Harry Potter (novel)/WMG/Main

The Sorting Hat is a Horcrux.
Like Riddle's Diary, the Sorting Hat belongs to that rare category of objects that can think for themselves. Nothing else in the series but a Horcrux has been shown to be capable of sentient thought (and personal creativity, as shown by its composition of circumstantially appropriate songs).

Over the next few years, the Statute of Secrecy and the Masquerade will fall apart due to the Muggle internet.
Now that most people have some form of digital cameras, something that used to be routinely Obliviate-able will be instantly uploaded to the internet. The resulting link on YouTube will go viral, and the Wizarding government will find it impossible to take down all the uploads/downloads of said video.
 * Alternatively, someone will witness a breach of the Statute and upload it, but no one will believe the video and assume it was due to special effects.

The mascots and God are behind everything
Recall the Love Room? It is implied God lives there. Considering that the "forces of nature" are implied to exist as well, we have ourselves a pantheon: Thus, the Wizarding World, and the universe at large, is governed by Eldritch Abominations following the classical esoteric theme, with four beasts subservient to the light. Those Lovecraftian beings passively possessed four people, guiding them to build Hogwarts.
 * Love/God represents Spirit
 * The Badger represents Earth
 * The Snake represents Water
 * The Eagle/Raven/whatever represents Air
 * The Lion represents Fire

Obviously, God Is Evil, and requires human sacrifice in order to operate, and so the beasts have been tasked to make the Wizarding World as violently elitist as possible. Sometimes, they are more proactive, and evil beasties like the Dementors are shat into existence to make everyone's lives miserable.

As their master dwells in the Department of Mysteries (though he sometimes shows up to the nearly deceased to torment them as he takes the appearances of their loved ones; his conversation with Harry was an exception because he wanted to have thw whole of Voldemort to eat and rape), the beasts are spread across the world, bringing misfortunes and evil. The Lion and the Snake were in Britain during the events of the series (although they were briefly in mainland Europe, specially when Grindelwald was active); contrary to popular belief, they're not enemies, but friends with benefits, and they thought the whole wars were not only funny, but sexually arousing. Meanwhile, the Raven/Eagle is in the USA and the Badger is in the Middle East, stirring conflicts among muggles and maybe also among the local wizard populations.

Cut to 2017, and their master will probably call them into direct action.

The reason Snape hates Neville so much

 * Neville reminds Snape of Peter Pettigrew. Not the sharpest tool in the box, kind of quiet, follows the Gryffindor trio around, probably similar in appearance. Snape still hates Peter for Lily's death, and takes it out on Neville.
 * But Snape seemed to dislike Neville before it came out that Pettigrew was the one who betrayed the Potters and he couldn't possibly have known the truth before if they didn't tell Lupin, who was James' other best friend and Snape had already fallen out with Lily and Dumbledore himself didn't even seem to know about the switch until the third book (he would have cleared Sirius' name if he did). Actually, if he saw any similarity to Pettigrew in Neville, you'd think he'd be nicer during years 1-3 because Pettigrew, as far as the world knew, had tried to avenge James and Lily's deaths.
 * Possibly, but Peter also went around tormenting Snape throughout his childhood, and Severus probably assumed that he was just doing it for James, not Lily.
 * Nah, it's because Neville could be the chosen one, and in that case he Lily wouldn't die. So every time Snape sees him he thinks about how Lily could still be alive if that little guy were chosen instead of Harry, and that makes him really bitter.

Snape asked to be sorted into Slytherin.
Come the end of Deathly Hallows, we are made aware of Snape's true loyalties, which actually marks him as more suited to any of the other three houses then Slytherin. He is found to be very brave, as a Gryffindor, smart (possibly to genus levels, if his old Potions book is any indication) as a Ravenclaw, and fiercely loyal as a Hufflepuff. He never shows the trademark ambition of a typical Slytherin, and it is known that he wanted very much to be in that House.
 * I disagree. I think he does have Slytherin qualities, and they're very prominent. Gryffindors are brave on the upfront, in the reckless kind of way, not in the sneaky way of Slytherin. We've seen that Slytherins don't want credit for helping, so they do it from the shadows, shown with Malfoy and his cronies, and the other Slytherins who were mentioned via Word of God for coming back. Hufflepuffs aren't just loyal, they're hard-working. Snape worked remarkably hard to keep where his true loyalties lie a secret, and worked hard as a spy for many years. I think Hufflepuffs are really just an extroverted Slytherin. Ambition is nothing without the hard work and loyalty to whatever one is ambitious towards, and likewise, what is hard-work and loyalty without ambition? Pottermore's opening letter for Slytherin states that Slytherins look out for their own (unlike Ravenclaw), and are loyal to those they care about, just like Hufflepuff. And as for Ravenclaw, we do see that Slytherins aren't stupid. Not all of them. Look at Voldemort, at Slughorn, at Merlin! None of those wizards were stupid. Just because you're smart doesn't automatically mean you're a Ravenclaw. Hermione, McGonagall, and Dumbledore weren't, and they're shown as being very, very bright. Snape belongs in Slytherin, he didn't ask. He would have asked for Gryffindor, to be with Lily, in the House he suits the least, since he lack's that bull-headed, up-front bravery that lacks any sort of level-headed-ness. Snape thinks things through and is brave from the shadows. Gryffindors just dive right in without much thought, or completely lose their heads trying to think (like Hermione and Molly). Slytherins can remain calm in the face of danger and think things through. Snape embodies Slytherin House.
 * In Snape's memory in Deathly Hallows, Dumbledore makes a comment that he thinks Hogwarts sorts their students too early. It's possible that Snape at age 11 was much more like a traditional Slytherin, but he's gone through a great deal of personal change, being affected by Dumbledore and
 * Yet all that—even Dumbledore's view—overlooks the key factor that would've overridden all young Severus's other aptitudes, placing him unquestionably into Slytherin no matter how brave, devoted, or intelligent he was. It's what made him the Spanner in the Works for Voldemort, and what gave him the strength to sacrifice everything he did throughout the series: the sole, driving ambition that never wavered, for all that bitterness and envy might've masked it. Namely, his ambition to become the sort of man Lily could've loved, and forgiven. No matter what it cost him, no matter how long it took, no matter how much hatred he might incur along the way. That's what Snape had wanted as a child, what he twice betrayed in moments of weakness he'd never forgive himself for, and what he died to live up to in the end. Ambition—pure, undiluted, Slytherin-caliber ambition—but directed toward a purpose Voldemort and his ilk could neither comprehend nor anticipate.

Hogwarts Houses of Adult Wizards.

 * Hagrid: Hufflepuff- He is unfailingly loyal to Dumbledore and Very hard-working. The exact traits Hufflepuff values.
 * Word of God says Hagrid is in Gryffindor. Also, Hagrid is incredibly brave in the books.
 * Cornelius Fudge: Slytherin- He displays a desire to keep his power as minister for magic and was always afraid that Dumbledore would take it.
 * Tonks: Gryffindor- She displays enough courage to become an Auror and fight for the Order of the Phoenix at a young age.
 * Word of God says Hufflepuff link
 * Scrimgeour: Gryffindor, pretty obviously. He's even compared to an "old lion" in the books.
 * Kingsley: Probably Ravenclaw - if he indeed went to Hogwarts.
 * Moody: Gryffindor.
 * Before I got on Pottermore, I assumed that Quirrell and Ollivander were Ravenclaws.
 * Newt Scamander: this troper assumed Ravenclaw, but Pottermore says Hufflepuff.
 * Dolores Umbridge: Slytherin, with the teensiest chance of Hufflepuff. She can be fanatically loyal when it suits her.
 * The Pottermore welcome letter for Slytherin says that they stick together and Umbridge is definitely keen on sticking together with her fellow Slytherins.
 * Dedalus Diggle: Yes - Dedalus Diggle. For some reason, I imagine he was a Ravenclaw. Capable, yes, but came off as somewhat odd.
 * Gilderoy Lockhart: You get the impression that Lockhart was a Gryffindor gone horribly wrong (cf. Peter Pettigrew, Cormac McLaggen) He's certainly got all of the bravado, but his actual courage and capabilities don't quite match up.
 * There's a picture of him in Ravenclaw quidditch robes in the second movie but it's debatable on how canonical that is.
 * I would say Slytherin, given how cunning and ambitious (in terms of fame) he is beneath that foppish exterior.
 * Pius Thicknesse: Slytherin. I imagine he was a pure-blood. However, he is also silver-tongued and is capable of putting on a good face for the masses - traits that Tom Riddle himself had in his early years and traits that Voldemort probably valued himself to the end.
 * Barty Crouch Senior—Slytherin. Not a bad dark wizard Slytherin, but the ambitious, political sort, akin to Horace Slughorn and the like.
 * Barty Crouch Junior—The hat *wanted* to put him in Hufflepuff, since his chief attribute is loyalty, but being a "Well Done, Son" Guy he begged to be in Slytherin like dear old dad. Unluckily for him, he was placed in Slytherin around the time of Voldy's rise to power, made friends with future death eaters, and was swayed to the dark side. It's also possible that since his father never paid him much attention, he looked to Voldemort as a replacement father figure.
 * (Madam) Rolanda Hooch—Either Ravenclaw (she's connected with a bird Animal Motif - eyes like a hawk and she flies a lot, albeit on a broomstick)...or Hufflepuff (fair play > referee)
 * We can probably safely assume that any heads of houses were students of said houses during their time at Hogwarts.
 * Aurora Sinistra: Ravenclaw. It would probably take a good brain for something specialized like the study of magic as it relates to stars.
 * Ludo Bagman: Slytherin. His nature is a bit slippery, and one can imagine that his housing didn't help matters at his trial. His age isn't given, but it's fairly likely that he was contemporaries with at least some of the first-generation Death Eaters. Yet, somehow he managed to slither in to a Ministry position after that trial and worked his way to becoming the head of the Department of Magical Games and Sports.
 * Rita Skeeter: Ravenclaw. Yes, her bitchy nature pretty much screams "Slytherin", but that seems a bit too easy. She seems to be a sucker for knowledge - or more specifically, knowing things that other people don't. (And then she twists that knowledge for her own ends, knowing that people also want to feel like they know things other's don't.)

Bertha Jorkins was pregnant
Voldemort's new body resembles a baby or a fetus, which came from Bertha after they had no more use for her memories. Her mind was too broken to possess, but she was already pregnant when they found her so they used her baby instead. I'd say Wormtail raped her, but considering he'd only been around Voldemort for that summer, that would only be possible if the Volde-fetus was only a month or so old. Though it would explain the tail...

Arithmancy is the art of creating new spells
Which an only be done by incredibly dangerous experimentation, eg: shouting random words, or an incredibly complex combination of maths and etymology.

Xenophilius Lovegood is the bastard child of Albus Dumbledore
They are both more than a bit odd, and this would of course mean that Luna herself is the direct descendant of Dumbledore.

The spell that Dumbledore cast at Voldemort at the end of Order of the Phoenix was an Elder Wand-level Petrificus Totalus.
Its effects are never revealed, and it's listed under Fate Worse Than Death, so, it could be a Petrificus Totalus so powerful it trapped Voldemort for all eternity.

Aberforth Dumbledore is almost as powerful as Albus
Come on: he's the brother of the most powerful wizard in history. It makes sense that he'd be extremely powerful too. The only reason he  was because he was caught completely off-guard by the unimaginable agony (Cruciatus) curse.

Merope Gaunt's 'dying wish' was a final spell
Specifically, that he would look like Riddle Sr. Descriptions in the book state "He was his handsome father in miniature." Could be simple genetics, but with a bloodline as tangled as the Gaunts, magic seems more likely.

Dolores Umbridge WAS a Death Eater
We know Voldemort had many plants inside the Ministry, and he would be expected to keep some of these very close to his chest, their true loyalty only known to him and themselves. The only evidence that she wasn't a Death Eater was Sirius saying so, and he would have had no way of knowing for sure and I don't remember him even giving a reason. She's clearly compatible with the party line (hatred of "half-breeds", no hesitation in using the Cruciatus Curse) and rose through the ranks of the new Ministry uncomfortably quickly for the former Minister's second-in-command (being that she was supposedly loyal to the old order, you'd expect them to lock her up rather than giving her another position of power). She was clearly in the Ministry simply out of a desire for power and no ideological reason, and it's easy to imagine her having her fingers in many pies in this respect: why be a mere Ministerial official when you can be a Death Eater and a Ministerial official? If Voldemort returns you can take your place at his side and if he doesn't you still have your place in the Ministry.

Ron is severely retarded due to inbreeding
It's pretty much canon that pure-blood wizards are all related, and the probably dumbest main character in Rowling's universe happens to be one. Coincidence?
 * Ron is sharp as a tack when he applies himself. Almost all of his grades are the same as Harry's and he is the champion chess player in the group.
 * Harry is hardly the sharpest tool in the book. Say Ron's grades match Harry's is hardly praise. Now if they matched Hermione's...
 * Regardless, he's not actually dumb, just lazy and reliant on Hermione for school (which, by the way, Harry also is). You can't be an idiot and be as excellent at chess as he is, and he has more than a few brilliant moments throughout the books as well. Now, Crabbe and Goyle, on the other hand, that you can make an argument for.

Snape had a good relationship with his mother.
He doesn't seem to have any hatred or resentment towards women in general; in fact, he appears to have had a great deal of respect for McGonagall (and not just because she could hand him his ass in a duel without breaking a sweat). This implies that he and Eileen were fairly close. (Maybe because Eileen knew a little something about being bullied at school, or they might have just stuck together because they didn't have anyone else to turn to.)
 * It was probably more complicated than anything. He was placed in Slytherin, which probably helped convince him to become a Death Eater in the first place. For a while, he was convinced he was an abomination because he was a half blood. After his mother's death, he learned, with help from Dumbledore, to forgive himself and her, which converted him to being in the Order of the Phoenix.

Crookshanks is the Potters' old cat.

 * Since we do not get a description of the cat that the Potter's had it could have some how survived the house exploding which made it's face squashed and unrecognizable to anyone that was friends with the Potters EG Lupin, Sirius. It knew that Peter was a rat and tried to tell Sirius, not Lupin because he was a werewolf. Crookshanks was looking out for Harry in the following years, even jumping on his lap in a latter book despite being very anti social with everyone but Hermione and Sirius.
 * Crookshanks didn't tell Remus because he was a werewolf?! That's one racist cat!
 * Maybe Crookshanks was AFRAID of Remus because he could very easily be eaten.
 * Are we forgetting that, whilst Remus was a wolf, Sirius was a dog? Why would Crookshanks prefer to tell either over the other, since Crookshanks could easily become the prey of either?
 * Have you ever even owned a dog? Dogs do not eat cats, and cats are not their "prey." But anyway, in the books, it says that Crookshanks could tell that Sirius was not actually a dog, which is why it was willing to work with him and help him find Scabbers.
 * It's possible, but he'd have been pretty old by then. (Assuming that the cat was, say, a year old or a little less when the house was destroyed, he'd be thirteen-ish by the time Hermione takes him in. Which isn't to say it couldn't happen, since cats can live to be 20 or older.)
 * Of course, he could be a human that transforms into a cat!
 * He is half kneazle, which might explain its long lifespan.
 * And the lady at the store said that he had been there for ages.
 * So are we agreed that Crookshanks is an Animagus? Maybe even Prof. McGonagall? Crookshanks could look different from the McGonagall cat in the first movie either from McGonagall changing the Animagus spell on herself, or just from inconsistencies. It's more likely McGonagall changed the spell, because they would have recognized her from the first year by the time Hermione buys Crookshanks in the third year.
 * He's not an Animagus. Word of God put an end to that rumor years ago on 2/18/04 in the "Rumors" section of her website. Plus, an animagus doesn't get to choose which animal they turn into. It's a reflection of the witch or wizard, so McGonagall is a cat because of her intelligence and independence and she's described as having markings around her eyes that resemble her glasses. (To further prove this point, look at Sirius. He's a dog with long, matted fur, because he's extremely loyal and unkempt.) And if you actually read the books, you'd know that McGonagall never transformed into a cat in front of the class in Harry's first year. She did so in their third year, after Hermione bought Crookshanks.
 * (same troper as above) It could also be Lily, Harry's mom. Considering that Sirius, Peter, and James were all Animagi, they might have shown her how to cast the spell. Then, when Voldemort "killed" her, she transformed into her cat form. She became trapped in that form, and waited thirteen years before she eventually gained contact with Harry again. This explains everything!
 * No, it doesn't. For the most part, it seems that someone's animagus form is the same as that of their patronus, unless there's a significant amount of emotional upheaval changes it, so Lily would've been a doe. Secondly, if Lily hadn't died, Harry wouldn't have gained the blood protection, and it kind of cheapens most of the emotional part of the series. And he wouldn't have been able to bring her back with the resurrection stone. Plus, Crookshanks is male.

Harry is killed soon after the epilogue
He has revealed to hundreds, if not thousands, of people that he is master of the Elder Wand. He may be a powerful wizard, but he's not the most powerful.
 * Harry put the wand back in Dumbledore's tomb, without telling anyone besides Ron and Hermione, after the battle. Why would someone go through all the trouble to kill him for something he doesn't have?
 * Because they BELIEVE he has the Elder Wand.
 * Not only that, but Word of God has said that wands are semi-sentient, explaining how Harry's wand . Just because Harry doesn't physically have the wand on him doesn't mean that he is not still  ; it's the wand's decision. The history of the wand shows that it has to be 'won', but   But Draco disarmed Dumbledore before Snape killed him, so the wand itself recognizes, due to the semi-sentient state Rowling has given it and the particular criteria the wand itself uses, which do not seem to line up with the common belief about how the wand is won. It does make sense that power-hungry people who want the wand might believe Harry still has the wand and go after him for it.
 * It also seems that the wand doesn't need to be present for its allegiance to change. Draco becomes the wand's master by disarming Dumbledore from the Elder wand itself, but Harry becomes the master by disarming Draco from his own wand. This means that the wand recognizes the first duel defeat as the moment ownership shifts, regardless of whether it is the wand being used by the current master at the time. Therefore, if Harry is later defeated even though he is not using the wand, the victor will still become the master of the Elder wand. There are probably a lot of methods possible to reunite a wizard with his or her lost wand, as it is the most important tool for a magical person and there have probably been countless retrieval methods developed throughout history. Once a person becomes the master they could probably find the wand. So it would make sense for people to come after or try to kill Harry even though the wand isn't on him.
 * Try to kill the most famous wizard alive, someone even Voldemort failed to kill when disarming him would suffice?
 * That'd be a tough out, to say the least. Keep in mind, by the epilogue, Harry is head of the Auror's Office. Obviously, he had some connections in the Ministry by that point and the fact that he's got, "Oh, by the way, I killed freaking Voldemort" on his resume didn't hurt him, but let's not kid ourselves. By the time he finally did kill Voldemort, Harry - mostly out of necessity - was a far more skilled duelist than the average 17-year-old. And in the 19 years following, he would have only gotten better with experience. And, of course, that's if you got to him. He would have no doubt been protected in the Ministry and in the field by a squadron of the Ministry's Top Aurors - most to all of whom probably also had some degree of experience in the Second Wizarding War. Then, if you got past the Auror Office's cream of the crop and beat Harry himself, then you'd have to get back out of the Ministry before anyone knows what happened, find some way to get to Hogwarts (which is protected) and to Dumbledore's Tomb (and nobody living but Ron and Hermione knows that the Elder Wand is indeed in the tomb), get back out of Hogwarts. All of that without being killed or disarmed or defeated in a duel at any point, because if you get killed, well, you're dead. If you're disarmed, then you're still alive, but all your previous actions are futile unless you somehow go back and beat the person that beat you. Long story short - pulling all of that off would probably require a Wizard to be just about as powerful as Voldemort, not to mention sneaky and a bit lucky. And even if someone succeeded, they'd have a target on their back like the last person that did it.

Harry Potter is a figment of Ron Weasley's imagination that Ron convinced certain people was real.
Harry Potter was created by Ron's subconscious as a perfect best friend that complements every trait of Ron. Harry is famous, an only child, rich, powerful, and adventurous; Ron is unpopular, is the sixth child of seven and youngest boy, poor, magically incompetent, and shy. Hermione, Ron's closest friend (other than Harry), was convinced that Harry is real. Harry is now a figment of both imaginations and is affected by this.

In their first year at Hogwarts, Ron and Hermione defeat the dark lord Voldemort. Since they are shy and don't want to jeopardize their families by the reputation of killing Voldy, they claim that it was Harry Potter who did it.

In their second year at Hogwarts, Ron's sister Ginevra is captured by a remnant of Voldemort, who magically wrecks her mind. Hermione stays in the hospital due to unrelated injuries. Ron goes alone to find his sister and helps her defeat Voldy. Sadly, Ginny is delusional and susceptible to suggestions. Because of this, she is convinced that Harry is real right around when Hermione comes back. Ron, Hermione, and Ginny make up a story about how Harry fought Voldy singlehandedly, rescued Ginny, and solved the mystery (which was related to his past). Now Harry has three believers and is affected by all of them.

Next year, Ginny spends most of her time at a hospital because of injuries both physical and mental. By the end of the year, she is healed and perfectly sane except for her belief in Harry Potter, whom she has a crush on. During that year, Ron and Hermione are involved with an escaped prisoner called Sirius Black. To cover up the facts, they pretend that Harry fought Sirius not quite singlehandedly, rescued Sirius, and solved the mystery (which was related to his past).

In Hermione and Ron's fourth year at Hogwarts, Ron begins to feel some resentment towards Harry. He realizes that Harry is getting credit for stuff Ron (and Hermione) did. Ron begins to consciously reject Harry; Hermione and Ginny keep the Illusion alive. Hermione, Ginny, and Ron fight Voldy once again, but they fail to prevent the death of Cedric Diggory. The three project their survivor's guilt and sadness onto Harry. Since both Ron and Hermione are sick of Harry by now, they curse him to eternal whining and survivor's guilt. The illusion of Harry is kept alive only by Ginny. Ron and Hermione begin to feel some romantic feeling for each other.

Next year, Hermione, Ginny, and Ron have yet another adventure fighting Voldy and his minions, which they once again credit to Harry because of their failure to prevent the death of Sirius. Hermione and Ron further develop their relationship, and Ginny still has a crush on Harry.

The same scenario is repeated in Hermione and Ron's sixth year—Hermione, Ron, and Ginny, after fighting Voldy's minions, fail to prevent the death of Dumbledore. Once again, the three project their sadness and survivor's guilt onto Harry as a coping mechanism so that they can have adventures.

In Ron and Hermione's seventh year, a lot of people die. Ron, Hermione, and even Ginny are sick of Harry, so they hallucinate that Voldy killed him. Voldy's death is attributed to Harry. But when Ron brought his memories to J.K. Rowling, for publishing, she demanded that Harry survive. This is the series we now know.

Witches born in May will marry Muggles
So goes the folk wisdom Ron heard from his mother, and the reveal date of Helga Hufflepuff's Chocolate Frog card would indicate that she was born in May. So she married a Muggle man named Smith, and that's why Zacharias and Hephzibah have such a common surname.

We could have been killed. Or worse, expelled!
This isn't a case of Skewed Priorities. Hermione's studies of "Hogwarts, A History" have turned up some disturbing facts about the expulsion ritual...
 * Alternatively, it may be that muggleborn wizards face tough time being expelled. This most likely includes memory modification to them and their relatives to prevent them from disclosing the magical world.
 * Would it be worse for someone to be expelled and keep their memory but not be allowed to do magic or to forget all about it?
 * Either way. One of two things could happen to Hermione: First, she could be forced to go back to her family and spend the rest of her life pretending that she doesn't realize there exists a whole magical world, never again performing magic or meeting with her friends, forced to never reveal the truth to any other Muggle by the threat of memory modification or worse. Second, she could have her memory wiped, which would probably be better in the long run, but which might compare unfavorably to death from Hermione's perspective. Both of these (especially the first) could arguably qualify as a Fate Worse Than Death.
 * Note that Hagrid was expelled, and had no consequences except being forbidden to do magic; but then he is not muggleborn.
 * Although this may be because Dumbledore went to bat for him, really knowing that Tom Riddle was the culprit.
 * This troper always felt that the punishment for expulsion (having your wand snapped in half) was unrealistically steep, anyway, given the fact that attendance at Hogwarts isn't even mandatory to begin with.

The Marauders Map Killed Fred And George
...Sort of. James/Sirius and Fred/George are so similar because the bits of consciousness in the map seeped into Fred and George, turning them into a reincarnation of the dead (or dying) marauders. This was probably unintentional on the part of the marauders, or done without considering the moral implications, but whoever Fred or George might have been was lost forever, tainted by a magical echo—an old joke.
 * They shouldn't have trusted something with a mind when they couldn't see where it kept it's brain.
 * ... Except they were pranksters already before they found the map.

Ambient magic has no effect on modern electronics on its own; the mental aspect of magic and the perpetuation of the myth that it does makes it so.
Electricity is a primal, elemental force, just like fire, light, earth, etc.; there are spells and incantations and potions that allow a witch or wizard to create or manipulate them, so electricity should be no different. (Light and electricity are very similar forces...) Plus, the effect of ambient magic on electronics has been displayed rather unevenly throughout the book series; sometimes it shuts them down altogether, and sometimes it leaves them entirely unfazed. Supposedly, a laptop or cell phone won't work on the Hogwarts grounds, but a motorcycle or car would; why would lead-acid batteries be more resistant that lithium-ion batteries? And there's a department in the Ministry of Magic created specifically for the discovery and confiscation of magicked Muggle items.

Given that much of whether magic works a certain way is in the belief that it'll work that way, the only reason ambient magic in an area would affect electronics is because the wizarding world believes that it does; otherwise, like anything else not intended as the direct target, the effect of magic on such items is negligible at best.
 * If magic truly stopped electricity from working, then the portion of London that contains the Ministry of Magic should be dealing with an irreversible blackout. It isn't. It's too much magic which overwhelms electricity. This also means that too much electricity should cancel out magic. But if you keep them balanced, both should work fine.
 * One badass fanfic assumes that lots of magic can cancel out technology and vice versa and goes on from there - it's why satellites don't pick up Hogwarts. Long story short, there's a squib with a grudge trying to expose the magical world; to protect herself from the wizard manhunt she's started, she hides out on a tech college campus (it might have been MIT), where there's so much engineering and technology that magic doesn't work. It's much less goofy than it sounds.
 * What's it called?
 * This Troper assumed that electronics didn't work on Hogwarts Grounds because they'd included anti-electronics spells in the wards around the school, intentionally so that muggle-borns get fully involved in the Magical world. They can make exceptions for teachers and lower the barrier during the summer, while the students are away. They made the wards, after all.
 * Or it's simply that all that magic -which we know can make light and whatnot, ie. electromagnetic interference, overwhelm electronic circuits and fry'em. A lead-based battery, with relatively short cables (compared to their diameter) connecting to the ignition wouldn't be affected, but the oh-so-delicate electronics just give up and spout the magic smoke of doom.
 * Alternatively, Magic has no impact on Electronics. It's simply a myth that it causes them to cease functioning because Wizards lag so far behind the mundane world. Notably, we never see anyone TRY to get it to work in the stories other than Arthur Weasley.
 * Alternatively alternatively, magic doesn't cancel out magic... when it's being used correctly. Hogwarts is full of students struggling to master spells, potions, etc.; the concentrated misuse of magic in a small enough area is enough to disable electronics.
 * Both the motorbike and the car that operated on Hogwarts Grounds had been magically modified. They likely didn't run on electricity any more, the ignition system was probably magical after Sirius' and Arthur's tampering respectively.
 * And there's also the Knight Bus, which also, clearly, has been magically modified, what which incredible acceleration, and the whole, things jumping out of its path trick.

== The Ministry of Magic is purposely keeping the Wizarding World ignorant of how the muggle world really is to prevent conquest-happy wizards from becoming unstoppable threats and to keep them under their rule. == Supposedly, the Wizarding World is purposely kept separate from the Muggle World to prevent the latter from decimating the former in a war and (presumably) prevent the latter from exploiting the former as a cure-all resource. While this may be true, there's also the added, underlying threat of what would happen if a wizard or witch suddenly came into possession and full knowledge of Muggle weapons and technology.

They say that against a wizard with a Killing Curse, a Muggle with a shotgun would win every time; imagine if said shotgun was enchanted and wielded by a deranged wizard. With the magic world completely inept in the ways of the non-magical folk, it ensures that they can't combine the best of both worlds and create an unstoppable weapon of mass destruction or invincible army to conquer both worlds. Plus, if wizards knew the ins and outs of Muggle society, technology, culture, etc., it's likely they'll pull an "Amish in the City" and abandon the old traditions for a more technomantic life, thus throwing the Ministry's carefully balanced iron grip on Wizarding society into jeopardy. Alternatively...
 * There's no way a muggle with a gun would beat a wizard with a wand. A quick Expelliarmus would disarm him straight away. Or if you don't feel like disarming him, which would be easy as hell, you could send a stunning spell or Perificus Totalus to knock him down. Or blast the gun out of his hands with Reducto. Or you could transfigure it into a rubber chicken. There must be some sort of spell that blocks physical objects, the shield charm for example. All relatively simple spells. Seriously, the muggle wouldn't stand a chance.
 * Compare the length of time it takes to finish pronouncing a five-syllable pseudo-Latin word to the time it takes to pull a trigger. Also consider that wands only work at pistol range, and firearms can work at sniper rifle range. And this is all before we get into grenades, bombs, artillery...
 * Wandless magic. Once Calling Your Attacks is out, all bets are off. Also, the Weasley's "weapons-grade jokes": conventional smokescreen vs. pitch-black Peruvian Darkness Powder; hypnotism vs. extra-strength Daydream Charms; complicated disguise makeup vs. a hat that instantly makes your head invisible. In terms of pre-packaged magic, wizards are at an advantage... after a pair of joke-loving teenagers put some thought into it. That no one thought to create some sort of "magic-bullet-proof vest" before probably falls into the WMG below.
 * Although most of those items are joke items, actual wizard combat powers doesn't seem to involve anything more powerful. Human (Muggle) science and technology is adaptive. Magic stagnates to the point that simple logic problems are considered drastic security measures.
 * Yeah, but at the same time the premise here isn't a muggle with a Gun. It's a wizard. With an enchanted gun. If a muggle with a gun is at a slight disadvantage (At best), a crazed wizard with a gun will have a significant advantage. If, some how, said wizard managed to avoid falling into the 'All important wizards are certifiably insane' aspect of the Potterverse setting, well, Wizards are screwed.
 * Speaking of wandless magic, uncontrolled wandless "accidental magic" seems to protect young wizards from mundane accidents (Neville bouncing like a rubber ball when dropped out a window, etc.). Perhaps this isn't restricted to the young. If Hagrid thought it ludicrous that a car crash could have killed Lily and James Potter, the same might hold true for a bullet or a bomb.
 * If that's the case, then why do people banish things at each other in duels?
 * Shield charms work to protect against moderate magic, not physical impact. Furthermore, wizards have and have used swords. If a SWORD could work on a wizard, there is no reason to assume a gun wouldn't.
 * Only on magical creatures, and it was a highly magical goblin-made sword.
 * When Ron comes back in book 7, Harry uses a shield charm to keep Hermione from attacking him. If it works on humans, why wouldn't it work on bullets?
 * Because humans dont break the speed of sound? The most likely conclusion is that a strong enough shield charm would stop a bullet from a high-powered gun. And that enough bullets would break the shield, just like Magic does in the books.
 * A shield charm can save you from falling hundreds of feet. Bullets don't actually have all that much energy; they are merely pointed, thus exert a lot of pressure.
 * Isn't it mentioned somewhere that the threat of uncontrolled magic is virtually zero once a wizard's been fully trained? Neville, Harry et al. had no idea how to use their powers, hence all the involuntary magic. Once they know how to use it, the threat goes down.
 * The same badass fanfic as last entry posited that the Ministry purposely censored all wizarding knowledge of technological process, starting sometime between World War I and the rise of Grindelwald. Effectively, this boils down to bitches don't know 'bout my atom bomb in later chapters. Wait...is the person writing these the author of that fic?
 * It's worth noting, in all this Fan Wank, that there's something not taken into account, and that's that, while a Wizard might be more than a match for a muggle with a gun, a muggle with a high-powered sniper rifle firing on a wizard who doesn't know he's even around is probably going to come out on top. Even if a shield charm stopped every bullet ever, and you could get it up before someone could shoot, you're not going to be able to stop a bullet from someone you don't even know exists.
 * This also goes the other way around; the Muggle with the high-powered sniper rifle is equally defenseless against a wizard who's scouted the area (magic would probably help a lot in finding a hidden sniper if you think it's a good precaution to check) and sneaks up behind him. This actually works against the WMG, however; all the wizards who would want to conquer the muggle world don't have this sense, they're too busy feeling superior to think about doing anything about the muggle with a gun than stand in front of him. The kind of wizard that's of the right mind to learn how the muggle world ticks and make this situation work for him would have no interest in doing so.
 * Magic in Harry Potter actually has a hard time detecting non-magical objects. But this discussion is Dramatically Missing the Point: There are about 10000 muggles for one wizard and those are definitely not the odds the Wizarding World wants to face. A wizard with a wand will not win over 10000 muggles with guns. A HP wizard is definitely not strong enough for that, so they defer to secrecy.
 * Mind you, all wizards can use magic, when all muggles are not soldiers...
 * Also, remember Moody's Foe-Glass? It seems actually quite simple to detect threats and enemies. It never says that the glass only detects wizards, and why would it? And this kind of magic surely can exist in spell form, or at least in more portable form.
 * A related idea: A wizard builds his wand into a shotgun, thus enchanting every shot fired with a spell. An Avada Kedavra blast would mean that every little piece of buckshot carries an instant-death curse. This would be bad.
 * Yep. But it would be much harder for him to cast lots of other stuff. Even the darkest wizard wouldn't deprive himself of a shield charm.

Unconscious Magic is Much More Effective Against Muggles.
We only ever see this kind of magic used against Muggles i.e. Harry Apparates away from bullies. However, this never happened against a wizard - Neville didn't do magic to save his parents, Harry doesn't Apparate away from Voldemort, etc. This would also tie in with the Muggle vs. Wizard scenario. Assume that a wizard can detect Muggle threats as they can the traces of magic, and a Muggle's a goner. Plus, a wizard world vs. Muggle world war would be a curbstomp battle in a wizard's favour: Apparate into the Heads of States' homes and capture them, break up supply lines, hide in Muggle-impenetrable areas, Transfigure armies' guns... the possibilities are endless. Finally, enchanted bulletproof vests, anyone?
 * You do know that Harry and Neville were babies and didn't understand what was going on at the time right? Unconscious magic happens when the user is angry or scared, besides, who says Neville was even with his parents at the time? If he had been, the death eaters would probably have tortured him to insanity as well. It'd probably be far more effective in making the Longbottoms talk. Besides, wizards who use unconscious magic aren't going to be more effective as trained wizards, because trained wizards can direct their magic in a more effective manner.

Magic makes wizards dumber.
Throughout the series, there are examples of wizards doing things that range from offbeat to wacky to downright mind-bogglingly dumb. And they show a remarkable lack of knowledge of anything Muggle—Arthur Weasley has no concept of how a bus route would work, or how to work a telephone even though one entry into the Ministry of Magic building involves one! -- despite a sizable fraction of them having at least one Muggle parent or grandparent. This has to make you wonder. And then it turns out that electronics in the presence of ambient magic tend to have (in the best of cases) little glitches and skips ... and what is the human brain but a great big meat-based gadget passing a lot of electronic signals between its parts and pieces? It's only to be expected that a brain might not work quite as smoothly as it should when there's a lot of magic around. (The survival value thus conferred on magic blindness through improved brain function may explain why the magic gene hasn't made itself ubiquitous in the population at large.)
 * The average wizard's ineptitude and insularity in regards to the muggle world that surrounds them may be Truth In Literature. Have you ever been to Quebec? In spite of being surrounded in their nation and all over its subcontinent by the two largest English-speaking nations on earth, not to mention being isolated from other francophones by an ocean, many [Quebecois go all the way through adulthood without knowing more than a lick of English. Modern-day speakers of various archaic British languages (Gaelic, Cymric, Armoric, Manx, Cornish, etc.) might be even more precisely what Rowling was referring to.
 * By "Cymric", do you mean Cymraeg? Like, Welsh? Sorry, nitpicky Welsh person speaking.
 * Maybe so many of the older, male wizards have beards because they don't trust themselves with big sharp razors? That is, they are too dumb not to cut themselves.
 * Alternatively, given the size of the wizarding population and the number of pure-blood families still in existence, maybe it's just all the in-breeding.
 * Further support comes from almost every muggle-born wizard being smarter. Hermione, Harry (a half-blood), even Tom Riddle (another half-blood despite what he tells people) - they all had a break every summer from magic brain-frying, in addition to having their important childhood brain development outside of wizard interference. The children of Purebloods are educated by wizards because of the Masquerade, and wizards are already dumber than muggles for environmental reasons; thus, the Pureblooded wizarding world is in a vicious cycle which is making it dumber and dumber every generation.
 * Going even further, Dumbledore knows this, which is why he spends so much time in Muggle society and why he sent Harry to live in Muggle-world.
 * This explains why Ron got progressively stupider and goofier as the series went on.
 * And that Brain-sucking jellyfish thing was beneficial in the long run, reversing the process to a degree by book 7.
 * It's not necessarily magic that makes wizards dumber; it's the overemphasis and over-reliance on magic to wizards. To wizards, magic is pretty much everything (fear of muggles, discrimination of squibs and those with muggle parentage, etc.); as a result, they exclude such things as muggle sciences and a lot of the arts from their education. All they teach in Hogwarts is magic: no English, no live foreign languages, no art, no theatrics, no psychology, no humanities in general, no courses on ethics. The only mathematics is Arithmancy; the only history taught is Wizard history, and that is taught very badly. Not an intellectual group for a race that reads a lot. If they were, many pure-blood supremacists would be against the concept of the Hogwarts Express because the steam engine and railroad system are a muggle invention; but none of them have seemed to realise that.
 * Reminds me of the "instinct vs. technology" aesop in Twister. Also, maybe in the HP 'verse, wizards invented steam power, but it took muggles to get it going, so to speak.
 * The children are taught those basic things until they were eleven, and it wasn't needed anymore once they went to a Wizard school. Maybe their brains developed quicker in Muggle studies, but then again that contradicts the whole theory.
 * Again, where do the children of Purebloods and other assimilated wizards learn these things?
 * And having a collective education level of an eleven-year-old about anything other than magic still explains a lot...
 * We only know what Harry knows, so maybe courses like "Magical Art History" exist.
 * It's highly likely that "Magical Art" and/or "Magical Art History" exists in particular, given the unusual nature of the paintings at Hogwarts (which must require magic paint, canvases, brushes, and a vivid imagination in order to create). A "Magical Photography" class is also probable. There are Wizard rock bands, who presumably use magical abilities in their music-making, although it's never explained precisely how (is magical music "better" somehow?). There don't appear to be any music or art teachers at Hogwarts, though. Based on statistics, there are probably not many Wizard musicians/artists in Britain, and so young wizards interested in studying music or art would probably have to become someone's apprentice.
 * Word of God via The Marauder's Map (which Rowling supposedly drew herself) shows rooms like "music room" and things like "charms club" are mentioned, so it's possible they exist, just as extra-curricular activities. Here's a link to a replica on ThinkGeek. And in the movies, it's implied that Flitwick is the choir teacher.
 * This troper recalls how much worse his ability to do simple calculations got since being given his first calculator in middle school...
 * Precisely. How badly did your ability to spell decrease once you stopped getting assessed on it? Unless the teachers also correct any spelling, punctuation or grammar errors (unlikely), then the average wizard is going to write like a muggle sending a text. Their should be some class where wizards learn basic English and mathematics, just to get their heads above water.
 * Or perhaps many wizards lack a decent capacity for critical thought due to their education at Hogwarts. Boarding school is a conformist place where standing out or thinking for yourself is a definite no-no. With no university or third level education to speak of, wizards and witches aren't going to be thinking outside the box. Consider the following points:
 * 1) Everyone was afraid of Voldemort when the Death Eaters did all the leg work.
 * 2) Some Death Eaters would have continued Voldemort's reign of terror when Voldemort disappeared, with it being business as usual.
 * 3) Being a Death Eater would be a lot harder, with many people going for the Dark Arts, homemade explosives, costly last stands, hit-and-run attacks, and vigilante work to make them pay, even using the same tactics they use.
 * 4) No one seemed to realise that a lot of Death Eaters attended Hogwarts when Dumbledore was teacher or headmaster, and aside from a few speeches, he and his staff did almost nothing to stamp out the rampant pure-blood supremacy or prevent students going to the Dark Side.
 * You have a very good point there, especially if you consider that both Hogwarts and the ministry are keen on proclaiming their opinions on young ones.
 * In the first book Hermione even says 'Most wizards don't have an ounce of logic.' when faced with Snape's potion puzzle, which supports this theory.
 * This is pretty much canon if you look at what Hogwarts actually teaches. They have a lot of practical, technical, and vocational classes, but there's nothing in the way of culture or literature or language or critical thinking, or anything else that most modern places teach. And, when you get down to it, they were complaining about things like writing four inches of an assignment or by the end 'Two Feet'. That's... two pages. Hand written. With a quill. 3-5 pages, Typed, is pretty much the norm in most Highschool Level courses these days.
 * ouch no wonder they were complaining their hands must have ached
 * Yeah, it's much more likely that the wizarding worlds complete lack of common sense is more of a cultural thing- they aren't going to know things that are exclusive to a culture they deliberately segregate themselves from. Their way of life is different, and it seems normal to them, the right way to go about things (sort of like how people in dysfunctional families sometimes have no idea they're actually dysfunctional, and don't know there's another way of going about things, which also means that the cycle can get repeated when the children grow up and start their own families... Not the most precise analogy, but good enough.) Although to add to the theory, I actually recently wondered myself whether or not magic does affect people's brains. Specifically, I wondered how wizards could be so stupid yet have such good memory. They learn all these spells, and seem to have to know how to brew all these potions by heart and so on, and it makes you wonder whether or not magic enlarges the parts of the brain involved in memory, and perhaps leads to other parts of the brain shrinking in response (maybe the part responsible for logic and decision making or something like that). I'm not sure whether of not their memory is only specialized in regards to spells, but I think it makes sense. Hermione is renowned for brains and excellent memory- maybe she developed it and treasured it because among muggles such good memory is extraordinary and those around her likely praised her and encouraged her to capitalize on that gift, whereas with wizards such a thing is normal and nothing out of the ordinary, and as such they weren't really encouraged in the same way Hermione was. Thus, ordinary grades. On the other end of the spectrum, we have Neville. Neville who was at first suspected to be a squib by his family- maybe his terrible memory is one of the reasons they thought he wasn't magical? (Even then, as far as I can remember, Neville doesn't seem to have trouble remembering spells and plant names- just other things.)
 * It doesn't necessarily take magic to make the brain favor memorization over, say, logic. Mental skills reflect usage even under perfectly mundane circumstances, sometimes to a surprising extent.

Slughorn gave Snape's old textbook with the notes in it to Harry on purpose to give him an edge.
Slughorn prides himself on kingmaking - hand-picking and fostering up-and-coming young witches and wizards. He could have noticed that Snape had a gift for potions and a bad habit of writing in textbooks and put two and two together, giving Harry the old textbook with the brilliant notes in it so The-Boy-Who-Lived would excel in a subject he has no real talent for. Plus, it's been established that Slughorn was teaching at Hogwarts when Lily Evans was there, so it's hardly out of the question that Snape, who started the same year, would have been taught by Slughorn.
 * The favoritism thing would be understandable, but his social networking skill relied more on finding already-talented people and giving them a leg up (tying a string of obligation and gratitude to them in the process). Harry had no talent in Potions outside of using Snape's notebook and, outside of possible Auror work, wasn't likely to use the subject at all, let alone achieve the kind of fame for it that Slughorn would be looking for.
 * Slughorn knew that Potter wouldn't be able to make it into Auror training without decent marks in Potions and suspected that becoming an Auror would make him that little bit more famous. And it would make Potter all the more grateful to Slughorn; Potter was already sufficiently famous to call in a few favours on Slughorn's behalf.
 * But Harry did have some potions talent. He had a pretty good O.W.L. score despite receiving no positive reinforcement, after all. As much as Snape was devoted to flunking him, Harry did more or less all right even with a clearly faulty (if Snape's notes are to be believed) textbook. Perhaps Slughorn noticed the latent talent and wanted to give him a better guide.

Grindelwald surrendered.
Rita got this much exactly right. Facing a duel against Dumbledore which could only end one way, Grindlewald allowed himself to be defeated. Perhaps there were a few minor sorties at the beginning, with both sides doing impressive looking but ultimately ineffective spells because of their unwillingness to strike the killing blow; in the end, Dumbledore backed Grindlewald into a corner and gave him no choice but to strike true or surrender, and Grindlewald folded. Cagey Dumbledore probably considered what his sacrifice would mean for the people of England: a win-win situation.
 * But in this case the Elder Wand would not've pledged itself to Dumbledore - its previous owner must be forcibly defeated for it to swing allegiance.
 * Define "forcibly." According to the fairy tale in-story, the brother with the wand had his throat cut at night- no magic duel or anything. So, the end result would be- if you lose in any way, you lose the wand. If Grindelwald surrendered, then he lost the battle. The fact that Dumbledore used psychology instead of magic or bullets seems irrelevant.
 * The "rules" for transference of allegiance seem sufficiently loose for almost any purpose.
 * For the Elder Wand to switch allegiance, its master needs to lose a confrontation against their will. Antioch Peverell getting murdered in his sleep obviously counts as this.

Ariana Dumbledore was raped.
The nature of Ariana's attack is left deliberately ambiguous. If what happened had been anything besides rape, it would have been described or at least directly stated.
 * Given the primary target audience of the books (older kids and teenagers), describing a rape scene wouldn't be nice to the readers. It would be traumatizing.
 * The exact quote is "They got a bit carried away trying to stop the little freak doing it. (...) It destroyed her, what they did: She was never right again." There were three guys, and one girl. Normal beatings normally don't have such traumatizing effects on girls, so it definitely had to be something much stronger. Also, the father wouldn't have risked himself Azkaban just because some punks beat his daughter, but I bet he would if she had been raped.
 * Anything JKR could write would pale in comparison to our sick imaginations.
 * It doesn't stop people who aim for Newbery Medals.
 * While this troper agrees it was suspiciously ambiguous (and I came to this conclusion myself), I can't fathom a 6 year old girl being raped just for doing magic, or even the implication of it being in a children's book. Picturing the Salem Witch Trials (movies/books, mind you), I can see them stoning her and yelling at her to the point where a 6 year old might be unstable. Or maybe I'm just in denial...
 * If they were throwing stones at her, then they would have been standing far enough away from her that she could have run away. The fact that she didn't implies that she couldn't, because they were forcibly holding her.
 * As this troper can attest, a sharp blow to the right (or rather, wrong) portion of the head by even a relatively small rock can instantly drop you and render you dazed for at least a minute, even if you are a twenty year old male in good health and the thrower was just tossing the rock aside fairly lightly. To a six year old girl who is being deliberately aimed at, I wouldn't be very surprised to find out that she suffered severe permanent trauma to her brain and enough temporary/permanent trauma to her limbs to keep her from running away. A thrown rock to the knee from a older teen/adult male would have a good chance of just cracking, or even outright breaking, her kneecap, for instance.
 * Or maybe they just got scared of her, thought she could hurt them, and beat her up just a little too hard out of fear. (is it wrong that this troper is disturbed by the fact that people seem to want this theory to be true?)
 * That's what I get out of the "They got a bit carried away trying to stop [her]" line above. That makes it sound like they were just scared and did something stupid in a panic. I don't see rape coming from that. The trauma could have been from her thinking they were going to kill her (near-death experiences really change people), or the event could have simply been the straw that broke the camel's back.
 * I think most people who subscribe to this theory forget that the muggles who hurt Ariana were children who were only a little older than she was. Rape probably wouldn't have even occurred to them and it's disturbing enough as it is that they traumatized her that much simply through torture without them being capable of something like that at that age..
 * Although in Brisbane in 2008 a 14 year old boy raped an older teenage girl. And there may have been adults involved that aren't specified. I don't think people "want" this to be true (Captain Obvious) but applying Rape as Drama - which can be therapeutic for people who have been raped, especially if they were children at the time. The fact that people won't talk about traumatic things like this is why childhood rape victims repress it for so long.
 * This troper knew a girl who, at the age of no more than 6, was stripped naked by a boy of about 8 who got her alone for a few minutes. Context suggests his motive was at least partly sexual, though he probably (hopefully) didn't know how to perform actual rape, and was quickly spotted and stopped. Without wanting to speculate further, TT wouldn't entirely discount the possibility, but still thinks it highly unlikely.

Voldemort subconsciously sabotaged his own plans.
Yes, Voldemort is a bad, bad guy who does evil things, but he's also his own worst enemy. The overly complicated plans, the "Give him back his wand" thing, telepathically revealing the location of all the horcruxes. He even destroyed himself at the end... it's all a cry for help from his well-buried conscience.
 * I honestly don't whether to glomp you or strangle you for that.
 * Not to mention the whole thing about making Horcruxes out of extremely conspicuous items rather than a random pebble or something. Vanity? Or self-sabotage?

Slytherin house was only kept open so that the sociopathic wizard children aren't mixed with the general population. It's the "special ed" section of the school.
Of course, it backfired; by now, it's become tradition, and nobody remembers the real purpose of the House.
 * Maybe the "special ed" class was made into Hufflepuff since there's not much mention of it or what the common room is like in the books and the Sorting Hat said they'd take anyone who doesn't fit the other three houses' qualities.
 * There are more qualities than courage, ambition, and wisdom, though. And given that later interviews suggest Hufflepuff's fairly comfortable as opposed to Slytherin's dungeons, well...

Slytherin doesn't have more evil people than the other houses; it's evil members are just more ambitious.
There are immoral people in all four houses. But, only a really ambitious immoral person would rise to become a murderer, or a dark lord, like Voldemort. In real life, most sociopaths are not violent, because nothing is motivating them to do anything violent, though they will do smaller cruel things to others. There are Hufflepuffs, Gryffindors and Ravenclaws who would sell their mothers into slavery if they thought it would benefit themselves. But they don't try to take over the world or kill anyone, because they aren't ambitious enough.
 * Looking out for yourself above others is specifically said to be, a Slytherin trait, as much as ambition is. I generally agree with your logic overall, though.
 * Except looking out for yourself above others is not really a Slytherin trait. Slytherins take care of each other, Ravenclaws are the backstabbing ones.
 * This is probably canon; I mean, look at Wormtail—clearly an evil person, but can't stand up for himself to save his life and always follows around the bigger, more powerful people. And he's a Gryffindor.
 * The Slytherin house probably wasn't always the dark wizard house. Or at least considered such. In the years shortly following the founding of Hogwarts it was probably know as the conservative/isolationist house. Considering the traits associated with being Slytherin, the house probably became known as the house for future politicians, spies, and aristocrats - and who likes them? (JK) It's probably not until the Wizarding Wars start that Slytherin starts to become known as the 'dark/evil' house. Give the Harry Potter world enough time and a lack of dark lords and I'm sure the stigma against the house will fade back to the usual.

Magic is a public utility
Just like water or the electrics. You pay your utility bill, the Ministry pipes magic to you. That's why the Weasley's being poor matters; they can't afford the magic. Harry has a trust fund (the Gringrotts vault) paying the bills, or maybe Hogwarts foots the bill for its own magic (as is likely the case for Muggle students).
 * And there's a limited (either total or slowly regenerating) supply, which is why the Wizards want to keep the whole thing secret.
 * Imagine the "Magic Crisis" and "The War on Voldemort: Is it just for Magic" headlines.
 * It exists naturally at low levels as a kind of background radiation; this is not enough to power an adult witch or wizard, but it is enough to get an untrained kid started. The ability to use magic is inborn but must be reinforced at an early age. This would help explain several things about both muggle-borns and squibs:
 * The presence of muggle-born witches and wizards - no adult magic-users to monopolize the magic supply, which allows the kids with magical potential to develop. Also, muggle-born and muggle-raised kids seem to be stronger, on average, than wizard-raised kids, possibly because they learned early on to do more with less.
 * Squibs tend to show up in pureblood families - wizarding children with naturally low sensitivity to magic may have trouble getting any at all if they're surrounded by a large family of magic-using adults. This explains why Ron and Neville both seemed to have trouble in their early years at Hogwarts but ended up being fully capable wizarding adults - both came from large families (Ron's immediate family was large, and it sounds as if Neville spent a lot of time with large amounts of his extended family as a small child), which lessened the amount of magic available to them.
 * The idea of their always being little magic to use could explain the small global population of wizard and witches
 * Can't be the Ministry controlling the supply though, otherwise how could condemned criminals (like Sirius, not to mention Voldemort himself) use magic if the Ministry could just cut them off?
 * I don't know. In one of the books it mentions magical food doesn't actually provide nourishment, and we've all seen spells eventually wear off. Perhaps the Weasleys house is built from regular construction materials, and the magic keeping it up has to be periodically topped up. And isn't the currency gold-based? If so, that also explains why poor wizards exist: it's the only element that can't be transfigured. (Well, it can be, but not everyone has a Philosopher's Stone.)

Cornelius Fudge is a Death Eater.
Or he's sympathetic to them. Look at what he did. He killed literally the only person who could corroborate Harry's version of events at the end of Goblet of Fire. Oh, he didn't do it directly; he let a Dementor do it, which conveniently allows him to plead stupidity (which Dumbledore no doubt believed). However, it would take utterly gross incompetence or negligence for someone to allow a witness to be killed in that fashion; it just makes more sense that it was intentional.
 * The Dementor was under orders from Voldemort to waste any potential witnesses.
 * If Fudge was willing to walk around with a Dementor, then he almost certainly knew how to cast a Patronus Charm. A flick of his wand could have saved Barty Crouch Jr.
 * The explanation they offered seems pretty reasonable, Fudge was terrified of the idea of Voldemort rising to power again and would do anything to remove evidence of that, not only to keep society from finding out and freaking out but also to maintain his own denial.
 * A boggart posing as a dementor was enough to stop Harry. The real dementors work by screwing with your mind. Fudge is hardly the most competent person around, and he's dealing with an international crisis (somebody's been kidnapped at the Triwizard Tournament), so it's doubtful Fudge would have been able to do anything. The reason Dementors don't waste Ministry folk is because that's against the treaty. Plus, this is Barty Crouch, who tortured the Longbottoms to the point where they turned insane- Fudge isn't the sort to think anything through, so he might have even supported the Dementor. So, incompetence, not malice.

Nobody heard the full Prophecy
Trelawney went through her trance; partway through, Snape was found by Aberforth. Trelawney came out of her trance thinking merely that Snape had interrupted; in all the hubbub, nobody, not Snape, not Albus, not Aberforth, heard the Prophecy in its entirety. It was only after the fact, via the Pensieve where he could focus on Trelawney without distraction, that Dumbledore realized just what Trelawney had revealed.

Salazar Slytherin, no matter what his descendants might get up to, was not such a bad sort
The Big Evil Man always seemed less a proto-Death Eater than a Batman-type - certainly not nice, but not evil either... just eminently practical. Considering the time period during which Hogwarts was founded, not trusting Muggle-borns was nothing less than common sense. "Let's see, you're (at least nominally) devout followers of a faith that comes right out and says in the source text, 'Thou shall not suffer a witch to live'? Why sure, come on in and hone your abilities! Maybe in ten years you can come back to destroy us at the head of a Crusading army, and say that your powers came from the Lord and allowed you to discover this den of wickedness that you might purify it!"

Plus, y'know... Slytherin's symbol is a snake. Serpents say 'European-style dark/light-duality wisdom cult', which at that point in history says 'completely wiped out (with maybe a few discreet exceptions).' Logically, the man's fear and anger could have been driven by bitterness over injustice that he experienced (cue any combination of Even Bad Men Love Their Mamas, Death by Origin Story / Death By Knight Templar, Abusive Parents, Parental Abandonment, and Rape as Backstory) as opposed to the simple arrogant disdain of most Slytherins we meet throughout the series.

It doesn't excuse his actions, but it does explain them - hell, for all we know, the Basilisk might originally have been intended as a failsafe. If Muggles ever tried to storm the school, they'd be met by Sal's successor and a little surprise.

Because of the overwhelming atmosphere of Does This Remind You of Anything? from Book 4 onwards (even if it derails a bit when you try to imagine Scrimgeour as Winston Churchill), this theory can be summed up as 'Salazar Slytherin Was Nietzsche Before It Was Cool.'
 * Probably he was some sort of Anti-Hero and just like Severus Snape: willing to sacrifice allies to pull off a bigger defeating scheme against the enemy.
 * Y'know, I'd buy this. It makes a lot of sense. For instance, Salazar Slytherin and Godric Gryffindor were supposed to be best friends before they had a falling-out and Slytherin left the school—it wouldn't make much sense if Slytherin was "the evil founder". In fact, in this light their falling-out seems like a clash between progressive and reactionary where both sides have valid points: Gryffindor argues "These children are witches and wizards and deserve to be trained just as much as pure-bloods", and Slytherin argues "These children have been raised by Muggles and are a potential fifth column, and can't be trusted". Of course, a thousand years later when magic has been fully hidden from the Muggle world and wizards are no longer persecuted, Slytherin's viewpoint is no longer applicable and all you have left is prejudice.
 * Plus, I bet Slytherin set up the Basilisk in the Chamber of Secrets as a secret weapon, fully expecting that within 20 or 40 years or so the school would be stormed by some kind of Muggle army, and Salazar or his kids would then get to tell all the other Founders that "I told you so." Right away, like, within a few years of the school's establishment, rather than centuries and centuries later and for completely different ends. It's a little on the paranoid side, maybe, but also pretty sensible given the times they lived in. If he had lived during Harry Potter's era (or the ones preceding it somewhat) and seen that Muggles were no longer a threat to wizards, he probably would have realized that all the anti-Muggle or Muggle-born prejudice had become a big, obsolete waste of time.
 * Besides, Slytherin doesn't leave in a blaze of glory, knocking off the muggleborns. He just leaves. Which seems... reasonable. He was best mates with Gryffindor, who I'm sure, would have something to say if his mate was a murderer.
 * I agree with all above. The Anti-Muggle movement Slytherin started was probably just a 'there's more of them than there are of us and they want us dead.' reaction. As proven by history, people justifiably freak out when people want you dead for something that's biological and you can't control. It's about 700 years later that the Statute of Secrecy comes out after the witch trials start; perhaps proving Slytherin had a valid point for the first time and revived his movement. It's around that time that the anti-muggle movement went from 'they want to kill us all' to a 'we're better off without them' movement. By Riddle's time the social/political philosophy has transformed into 'we're better than them' as expected of a culture that's been practicing isolationism for roughly 300 years. The Slytherin house probably did not become the home of 'dark/evil' wizards until Grindelwald and Voldemort started recruiting. I mean I bet his house was heralded at some times in history as the house where all the 'good' wizards end up and the Gryffindor house was looked at as a mix of the well-meaning idiots that will get us all killed and the dark lords who are bold enough to be braze about it.

Dumbledore's unidentified spell in The Order of the Phoenix was meant to destroy or remove Voldemort's soul
The spell is only performed once, never connects, and is described rather impressively. Voldemort retorts that it is foolish that Dumbledore not seek to kill him, to which Dumbledore responds that there are other ways to destroy a man. When "destroy" is used in reference to people, and death itself can be referred to, "destroy" implies something horrible such as complete mental breakdowns or worse. Given the stories' emphasis on the Soul, destroying Voldie's soul makes the most sense. Include that the prophecy indicates that Dumbledore can't kill Voldemort (although the sixth book Josses how accuracte prophecies are), and destroying Voldemort to leave Harry to finish off seems reasonable.
 * But then, if this spell connected, Dumbledore would probably become a Dementor by doing the same thing they do.
 * There are so many alternatives... To say, the spell could have worked by forcing Voldemort to feel remorse for his (many) sins. Ghost Rider uses it a lot, and works.
 * That's what this troper thought as well. Hasn't it been said that forcing Voldemort to feel remorse would kill him or cause extreme pain, or something to that effect?
 * Bearing in mind that Voldemort's body contained only 1/7 of his soul (so the spell wouldn't have done anything except dely his rise further) and Dumbledore's hatred of Dementors, this seems unlikely. Something to do with love, or the remorse idea above, seem far more useful and in character.
 * Technically, Voldemort only had 1/128 of his soul left in him...
 * You forgot.
 * Actually, it is 1/128..
 * Nowhere is it etched in stone that every single successive horcrux split leaves the soul in an even, neat division by perfect mathematical fractions. In fact, probably the split is uneven in favor of the part of his soul left in his body, since this is explicitly said to be the central part of him now.

Riddle and his Death Eaters are the last part of a Dementor plot to collapse Wizarding society
This comes from here - and it makes sense.
 * Why, exactly, would the MoM keep the Love door locked? Because that was part of the bargain that got the Dementors working for them. But the Dementors aren't satisfied with the morsels thrown to them, and they want more. They want a cold world, filled with fear and hate, that they can feed from. Hey, look at the Death Eaters' aims: inspiring fear and hate! And it's not like anybody was around to protect Riddle as a child. They found the perfect candidate for the job - a wizard baby who would be around Muggles until he was old enough to go to school, by which time their Mind Rape would be complete.
 * Dementors feed off happiness. They merely leave despair behind.
 * Then why does a ball of pure happiness chase them off? Shouldn't it be like candy for them?
 * The basic form of the Patronus Charm is like candy to them. What the basic form does is form a shield or decoy that the Dementor feeds off instead of the caster. Presumably, the attack form is like being bludgeoned over the head with a giant novelty chocolate bar.
 * Dementors feed off of misery. That's why they start breeding when Voldemort comes into the open. They are repelled by happiness, and so as a defensive mechanism they suppress happiness in their victims and feed off of the depression that arises as a result.
 * If the Dementors ate misery, then after they left, their victims would be happier. They showed up at that Quidditch game in the third book because so many happy people were in one place. People feel like crap when they breed because the Dementors are eating all their happy thoughts.
 * Who said the people at the Quidditch match were happy? For starters, it was a sporting event; at any given time at least have the crowd at a sporting event are unhappy with the game's progression. It was between Hufflepuff and Gryffindor, so it wasn't an interesting inter-house rivalry match you'd get with Gryffindor and Slytherin, so it didn't create that kind of rapid obsession. Slytherin and Ravenclaw didn't have a vested interest beyond who would play who in the next game, so they aren't creating any strong happy feeling. Added in to all this is the fact it was a thunderstorm and the entire crowd was being rained on. It wouldn't be impossible that many of them were not happy at all. The only people who would be genuinely happy are the sadists who want to see who got injured worst playing in these awful conditions, and the die hard Gryffindor and Hufflepuff fans who wanted to see who beat who. Been a while since I read the book, but I'm fairly certain it was just "powerful" emotions.
 * Or the Dementors do eat misery, but the feeding process is similar to a mosquito that injects you with anticoagulant so the Dementors use an emotional equivalent of an anticoagulant to bring up successively worse and worse memories to feed off of until you drown in them.

Dumbledore had a magical duel in the London Underground.
Where did Dumbledore get a scar that looked a map of the London underground on his right knee? Perhaps during a fight (maybe with Grindelwald) in a London Underground station, his knee hit a map, and with melting bits of metal and plastic (or metal and metal) all over the place, his knee was scarred...
 * That must have been a very small map.
 * Or it had been shrunk with magic!

Neville was placed under a memory charm when he young.
Perhaps the reason Neville was so clumsy was because someone tried to make him forget something when he was a baby. Perhaps he had witnessed his parents being tortured, and then someone (like his Granny) placed a memory charm on him so he would forget about it. We have seen Gilderoy Lockhart having his memory modified, and he is clumsy and forgetful much like Neville was portrayed. Maybe something happened to him in Book 7 so that he recovered and became competent. Remember how his remembrall from Book 1 always glowed, trying to tell him he had forgotten something? (Though apparently severe magic damage like this is usually untreatable.)
 * A fanfic series touches on this. In that 'verse Neville was partially memory charmed, having seen his parents being tortured as above, by Lockhart before Mad-Eye Moody stopped him from turning toddler Neville into a vegetable. In his 5th year Neville starts dosing himself with a memory enhancing potion and takes a level in badass, even defeating Harry in a duel. If only Canon Neville had the same potion, he might not have had to wait until the last book to do.....anything.
 * His grandmother probably put the charm on him because infant Neville had been around when his parents were tortured (Bellatrix probably just ran out of time to kill or hurt him). In her own shock and horror, his grandmother overdid the charm, which would help explain her pressure on him to do well - she always felt guilty about having accidentally harmed him after what happened to his parents, and wanted to see him get over the damage already.
 * Most likely Jossed. Nothing was ever mentioned of it in later books. Besides, wouldn't the attack have happened at a point when Neville was too young to remember?

Kreacher fixed the Vanishing Cabinet.
When Harry Potter told Kreacher to keep an eye on Malfoy and to not let on to him that he was being followed, he didn't specify to Kreacher to not help Malfoy in whatever he was doing. So to help this relative of the Black family, Kreacher looked at the Vanishing Cabinet and fixed it without Malfoy knowing about it. (One of the dangers about trusting Kreacher not to twist around your orders when he doesn't like you.) Remember how surprised Malfoy was when it finally was fixed, as if he hadn't done it himself?

The Restriction of Underage Wizardry is an attempt to avert Schmuck Bait laws in the face of the Masquerade.
It is shown that the Ministry neither knows nor cares if underage wizards and witches practice magic in a magic household or other such situation; but any underage wizard that uses magic in a non-wizarding area is immediately busted. It is likely that the Ministry phrased this law as they did so that underage wizards can intentionally disobey in ways that don't break the secrecy thing and keep the muggle unawareness thing as a "more important law that shouldn't be broken" (as well as make it look like they aren't being unfair to muggle-borns).

Slytherin sorts for sociopathy
This is just a necessary non-canon assumption for the Wizard of Oz and special-ed theories above.
 * Ambition, guys, ambition... Ambition and sociopathy have a high correlation.

Lockhart was already under a memory charm
Think about it. He claimed that he tracked down these people who saved lots of lives, found out how they did what they did, and wiped their memories. But for no one to call him on it, he would also have to wipe the memories of those they saved, everyone in the chain of information that eventually led him there, and anyone else in the chain of information that led him there. It's much more logical to assume that he did those things himself but, realizing that he could be a serious threat if he ever came after former death-eaters, the Death Eaters put him under a memory charm to make him forget his skills and become incompetent. He was always a braggart, but once he was at least an honest braggart.
 * Jossed by Word of God; she wanted him as a joke character, as she knew a guy exactly like that.
 * This sort of thing makes Death of the Author tempting.
 * What reason do we have to assume that Death Eaters would solve the problem of this dangerously talented wizard by Obliviating him instead of simply killing him like they do to every single other one of their enemies throughout the series?
 * As a form of mockery. They're sociopaths, you must remember.
 * Since when is Lockhart a "dangerously powerful wizard"?

Gryffindors and Slytherins normally leave each other alone.
The two houses have a long history of being completely awful to one another; because of this, members of the two houses tend to avoid each other. In each house are a few complete jerks who go out of the way to screw with members of the other house, becoming representative of it in the process. As a result, each House seems to the other to consist only of the most evil students to the other.
 * To clarify this a bit: as observed in the movies, Slytherins and Gryffindors will happily associate with everyone except each other.
 * There are several things that could explain why this is true: for one thing, the obvious fact of the books being from Harry's perspective means we see the Slytherins at their worst, because he commands such a high profile that he attracts excessive attention anyway, both good and bad. Also, the Malfoy wields a great deal of influence, and given the way Harry snubbed him, some of his year-mates probably found it easier to fall in line. (This ties in with a related argument that less Slytherins are Death Eaters than it appears, for similar reasons: the ones who aren't feel less reason to antagonize Harry, and so simply don't interact with him much and get little screen time.)
 * Probably an even better explanation - Slytherin has as many "evil" or unsavory characters as it does because it is filled with the children of Death Eaters, a wave of kids loyal to their parents and/or bent on revenge. If Harry had joined Hogwarts in any other generation (besides the one immediately before his), he probably wouldn't have found so many antagonistic Slytherins. This may or may not extend to his kids' terms, as some of the children of Death Eaters may have held grudges to adulthood, while others did not (I.E, Malfoy's lack of antagonism).

The Sorting Hat takes into account family relation when sorting

 * Thus explaining why a cowardly traitor like Pettigrew and a moronic lackey like Goyle got into Gryffindor (bravery/loyalty based) and Slytherin (cunning/ambition based) respectively. It's similar to Harry choosing to be in Gryffindor, in this case more like, because your family is so ingrained in the house that that ties of family will be a factor rather than one's personality.
 * Pettigrew could conceivably fit under loyalty - his loyalty was to the strongest and was of the slavish kind. Goyle could easily still qualify for ambition - you don't have to have brains to be ambitious. But as is mentioned elsewhere, student's wishes can influence or change the hat's decisions.
 * Hasn't Rowling said the Sorting Hat's consideration of Slytherin for Harry was due to the bit of Voldemort inside him?
 * Really? Well, so much for the similarities between them. Harry's always been perfectly perfect and pure then, and one of the most interesting aspects of the series (that it's our choices that make us who we are) was never true at all.
 * I can't find a single piece of evidence that Rowling ever said that. Besides, Dumbledore very capably sums up why Harry would've done well in Slytherin in Chamber of Secrets, and certainly doesn't say anything about the soul(which at no point in the series did Rowling show to effect Harry's actual personality) being a factor in all that.
 * Well, think about the two Slytherins in the story who were shown to have had no business being in that House whatsoever: Regulus Black and Severus Snape. If the Hat really did Sort on personality alone, Regulus would have been put in Gryffindor and Snape would have ended up in Ravenclaw. But think about just how deeply ingrained both the Black and Prince families were in Slytherin House. Same thing with the Weasleys: Ron really didn't have enough courage to be in Gryffindor (running away and boo-hooing because he was hungry? Yeah, I want him on my team if I have to defeat a genocidal maniac!), but the Hat put him there anyway because the Weasleys are a Gryffindor family. If someone from a pure-blood family with a long history in one particular House doesn't want to be there, they have to specifically ask not to be Sorted into it (see: Sirius Black). So really, the only students who are Sorted by personality alone are Muggle-borns. It makes perfect sense.
 * Snape, no business being in Slytherin? I don't know what you're thinking, but Snape seems pretty much the archetypal Slytherin - he's cunning enough to deceive Voldemort, ambitious enough to excel in Potions as he did, etc..
 * Adding to this, Fred and George are Ravenclaws, Percy's totally a Slytherin, and Ron would probably be Hufflepuff.
 * Sorry, but anyone who says Ron wasn't brave clearly hasn't read the books properly at all. Plus, there's the difference between Padma and Parvati, and the placement of Sirius, and the presence of all the Muggle-borns. The high correlation between families and houses is more likely due to the fact that the Sorting Hat honors choices—students from old wizarding families would be placed into their preferred houses as long as they were reasonably suited and the reason for their preference was not petty. Perhaps Peter's placement could have been something like this: Peter sees the three friends who he met on the train get (alphabetically) sorted into Gryffindor. The Sorting Hat decides that since he wants to go there so much, there was a genuine chance that Peter could grow into a brave wizard if he had such good friends to guide him. A major theme Rowling writes into the books is that choices win out over abilities, and so the house system is more guiding students into whichever house would help them reach their potential and make these choices clearer, rather than sorting solely on the basis of ability.
 * Except Potter is after Pettigrew alphabetically. Which raises the observation - Sirius was that sure James would be a Gryffindor, that he asked to be placed there before James was Sorted. Sirius must've really liked his new friend...
 * In Sirius' specific case, simply wanting to be in Gryffindor proved he had enough courage to qualify, since it involved going against the clear wishes and values of his family.
 * We don't know that the Prince family was ingrained in Slytherin house, as we know next to nothing about them. In fact, the clues in the books imply that Eileen was not a pureblood witch (in particular something Bellatrix Lestrange said when visiting Spinner's End, saying they were probably the first pureblood witches to ever set foot in that place) and that perhaps the 'half-blood prince' nickname Snape chose for himself was an ironic one, because most members of his family were half-blooded. This doesn't mean the Prince family didn't have a history of being Slytherins, but it is less likely than it would be for a pureblood family like the Blacks, whom we're explicitly told have all been in Slytherin for generations until Sirius. We're not even told what house Eileen was in, it just seems likely it was Slytherin because Snape already wants to be placed there.
 * Eileen was a pure-blood and a Slytherin. Also, Bellatrix is an Ax Crazy pure-blood supremacist, and was speaking like an Ax Crazy pure-blood supremacist when she said "we must be the first [pure-bloods] to set foot here." (She didn't like or trust Snape, remember?) Then consider that many cities in Britain [including Yorkshire and Manchester, the two most likely locations for Spinner's End] are almost a thousand years old; there is no possible way that Bellatrix or Narcissa could set foot anywhere in the country and be the first pure-bloods in that area. And lastly, it was stated in the books that Snape nicknamed himself "the Half-Blood Prince" because he, himself, is a half-blood.
 * I always figured that Regulus went under the hat thinking 'Not Gryffindor, not Gryffindor' the way Harry thought 'Not Slytherin' simply because of how he saw his parents treat Sirius when he became a Gryffindor.

The Pureblood agenda is ironically the only thing that's kept wizards from dominating the Earth over Muggles.
The Wizardry genes are dominant, and they commonly occur as a mutation in the non-Wizarding population. Also, wizards can live 100 years longer than Muggles and have the opportunity to reproduce more. In a case like this, the population of wizards should be high in this world, about as common as brunettes. However, the Pureblood movement, which encouraged inbreeding and sticking to wizarding stock, has limited the spread of the genes. With Voldemort's influence gone and the movement losing favor, it's quite possible that in the next 1000 years, Wizards will outbreed Muggles.
 * When Harry entered Hogwarts there were 39 other first years. According to Word of God, the average intake of muggleborn wizards is about 25%. That's about ten muggleborn per year out of the sixty million that make up the population of Great Britain, so it's not exactly common. And it's not clear whether all wizards live as long as Dumbledore (barring accidents) or if it's just the magically powerful ones. And a large population is much more difficult to hide. Hell, it's entirely plausible that over the next 100 years or so, the Masquerade will become untenable because muggle population increases squeeze the Wizarding World out of its hidey-holes. They're outnumbered by about five orders of magnitude; the planet would bust a seam before they made up that sort of difference.
 * Word of God thoroughly admits that she sucks at Math and that she imagined the population of the school at about 600~800 students, not the 280 that it would need to be if she had done the math. But yes, Wizardry is still quite uncommon, just not quite as bad as it seems. Also, the Hogwarts population does not take into account homeschooled kids, which no doubt some are in some of the more pureblood families. Also, in the 4th book, Malfoy says that he had intended to go to Durmstrang and that his Mother hadn't wanted him so far from home. So it is probable that a number of pure-blood and half-blood children study overseas. The sizes of Durmstrang and Beauxbatons are never mentioned; nor is it said that they are the only wizarding schools in their respective countries, although it is implied. Nor do we know how many other countries have wizarding schools.
 * Counter-argument: Muggle population density is utterly irrelevant to wizards, who can magically expand space in a Bag of Holding manner. Moody's seven-compartment trunk could probably be used as a luxury apartment - or seven efficiency apartments. It wouldn't matter if the population of Britain were a million or a trillion.
 * Also, Harry and his classmates were born during a civil war. Its entirely possible that the birth rate was dramatically reduced, meaning that there was a far lower intake of students than usual that year.
 * And then there's the possibility of the majority of wizards and witches being home schooled instead of going to Hogwarts. Population at Hogwarts doesn't necessarily equal total wizarding population of the U.K.
 * Regardless of the *wizarding* population at large, that doesn't change the fact that only, based on Rowling's vision of the Hogwarts population rather than her incredibly crappy math version, 28 new Muggleborns join British wizarding society every year. 700 million children are born in the UK every year. Since it's highly doubtful that there are more young Muggleborns being homeschooled, the likelihood of them rapidly growing the Wizarding population is slim at best. It's also likely based on the mass inbreeding of pureblood society that they have a low population as well. Most of magical society is probably Half-blood, meaning they bring with them a blend of modern muggle attitudes and wizarding traditionalism. As a result, they aren't going to go off any marry and have children with a much younger woman after the one they're with stops ovulating (note, it doesn't matter how old a wizard or witch can get, it doesn't mean they can have children later).
 * "700 million children are born in the UK every year", er, don't think you meant the 700 million there mate, the UK population is only 60ish million to start with.
 * Dominant does not equal common. Dwarfism is also a dominant trait.
 * In the comments in The Tales of Beadle the Bard, Dumbledore says it's likely that all (apparently) Muggle-born wizards and witches have some wizarding ancestry. He doesn't say why he thinks that, or whether it's a mainstream view, but it casts doubt on the idea that any Muggle could give rise to a magic user by simple mutation. That and the existence of squibs also suggests that wizardry doesn't follow simple Mendelian dominance.

House-Elves have hammerspace powers.
In the second film, it was supposed to look like Dobby had pulled the letters from his pillowcase; but the hole in the side for his arm was too high for when he removed the letters, and the edge of the hole for his sleeve was in the middle of where he disappeared the letters to.
 * according to parodies, he pulled them out of his ass....


 * Remember Hermione's Bag of Holding, showing that Hammerspace is a common occurrence in the Potterverse. Now given that House-Elves imitate human magic with their own, wand-less variety, this is practically canon.

Mrs. Norris is an animagus.
Possibly failed partway through her unauthorized training, so she can't turn back. Not just a really smart animal owned by an obsessive lunatic. So... yeah, that's all.
 * It's more probable that Mrs. Norris is part Kneazle, which are smarter than average cats (as Harry's Crazy Cat Lady squib neighbor can attest).
 * Rowling says that Mrs. Norris is just a very unpleasant cat.

The amount of magic in the world is finite and will eventually be used up
the world population of wizards is small because there would not be enough magic to fuel the community if it was larger. The difficult to use spells are only difficult because wizards have to gather a lot of magic for their use. Also squibs; like in another WMG are low sensitivity individuals who can't store enough magic to use their abilities.

One thing the Arithmancy class teaches is how to divide by zero.
A Wizard Can Do It. There has to be some reason it's called Arithmancy instead of Arithmetic. (Alternately, it's controlling reality via numbers instead of Canis Latinicus, but while interesting, it leaves zero indivisible.) comes to maths) would prefer it to something as woolly as Trelawney's Divination classes.
 * Uh...Arithmancy is a real word. It's fortune-telling by numbers. Also called numerology. Since we never get a look inside Hermione's Arithmancy classes in the books, we don't know if it's the same thing, but if it is, it's obvious that someone like Hermione (who likes structure, which is kind of mandatory when it
 * That would be Divination.

Ron is a seer.
This is based on 2 things:
 * 1: In Deathly Hallows, Ron almost predicts the taboo on saying "Voldemort." The exact words were "It feels like a jinx or something."
 * 2: His ability at Chess suggests that he has a well-developed sense of predicting moves.
 * Also, his predictions for Divination in Goblet of Fire (and Prisoner of Azkaban) are extremely accurate. Specifically, he predicted that:
 * Harry would work for the Ministry of Magic. He decides to become an Auror starting in Goblet of Fire.
 * Harry would receive "a windfall, unexpected gold", to which Ron requested Harry lend him some of it. Harry later won a huge amount of gold in the Triwizard Tournament, and he gave it to Ron's brothers.
 * He comes from a very old, powerful (the Prewetts) magical (hey, pureblood) family. Prophecy is apparently a genetic trait (as in Sybil being related to great seer Cassandra Trelaney) so it seems to be the sort of thing that would pop up most in families with a long history of magic, rather than muggle borns.
 * The movies (and we know JKR does plant clues in them: Hogs' Head goat, anyone?) have this bit of dialogue that seems to point to this theory.
 * Trelawney: Your aura is pulsing! Are you in the beyond? I think you are!
 * Ron: Sure
 * In The Chamber of Secrets we get this: "Could've been anything," said Ron. "Maybe he [Tom Riddle] got thirty O.W.L.s or saved a teacher from the giant squid. Maybe he murdered Myrtle; that would've done everyone a favor..."
 * Okay, so I thought this was interesting enough to google it. The first three results were all Slash Fic. Seriously, people?

Dumbledore is senile.
Which is why he's such a Cool Old Guy in the first few books ("As long as they don't take me off the chocolate frog cards!") and such an Idiot Ball-toting Jerkass in the last books. Same reason, different symptoms. He's not wise, he's just a Seemingly-Profound Fool. The times he was Badass in battle was because he was lashing out with his coolest spells at someone who PO'd him, not because he's all that competent.

The Basilisk was actually a secret keeper
In his old age, Salazar Slytherin became more and more paranoid, Mad-Eye style. He had an understandable distrust of muggle-born wizards (there were witch-hangings in his lifetime), and so he built the chamber of secrets as a repository of knowledge and hid it under a proto-Fidelius with the basilisk as secret-keeper (and secret weapon in case Hogwarts would be overrun by hostile forces). Sadly, the proto-Fidelius charm works differently from the modern version - when the basilisk died, the entirety of Slytherin's secret library was lost forever.
 * Or, more likely, Tom Riddle took everything that was in Slytherin's library when he discovered the Chamber of Secrets during his time in school.
 * Never mind the bit about the basilisk dying locking them out, as they . Anyway, this is Fridge Brilliance as far as this troper is concerned, finally laying to rest the years of contention over how the Chamber could've gone undiscovered all those years and how its entrance was in a 20th century bathroom despite being built around 1000 A.D.. This troper assumed the castle morphing took care of it, but this clinches the method of how.

The post-Prizoner of Azkaban timeline is an alternate timeline.
If Hermione hadn't gone back in time, Siruis and Buckbeak would've died, thus rendering all of Harry's Sirius related actions in the later books null and void.
 * So James Potter is alive?
 * No because he died prior to the start of the story. I'm talking about everything past PoA.
 * The other poster was saying that if Harry and Hermione hadn't gone back in time, the trio, Sirius and Snape would all be dead (or rather soul-sucked) since the time-traveling Harry wasn't there to save them. Hence, Harry couldn't have gone back in time to save them without having already been saved, resulting in a paradox which can only work in a "there was no first time" universe. Therefore, alternate timelines are impossible in the Potter Verse.
 * No, Harry, Hermione and Sirius would be dead or soul-sucked, as Ron and Snape were not present when the Dementors attacked, they were still up near the whomping willow. Also, being that they were both unconscious, it's unlikely the Dementors would have been able to detect them (the Dementors couldn't even identify Sirius when he was in dog-form because of his simpler mind, they probably wouldn't have been able to 'see' unconscious people unless they already knew they were there/were already in the process of feeding off them).
 * [petulant tone]Actually[/tone], I was saying the Harry wouldn't have been there to be seen on the first cycle, and it doesn't matter if he would have died or not (he would have, though), because if it wasn't a Stable Time Loop the 0th-cycle version of him would never have traveled to the first cycle, the first-cycle version would have had to have had a reason to behave the way he did (waiting by the lake, jumping out and using a full patronus) and the second and later cycles (which the canon version of PoA would necessarily have been) would have been functionally identical to a Stable Time Loop, with no changing the past.

Voldemort's rebirth potion.
The reason Voldemort went through that incredibly circuitous plan with regards to Harry and the Triwizard Tournament is because the rebirth potion can only be used (or used to its full effect) if brewed on certain significant days of the year. Those dates are likely ones that are connected to death, like Halloween, or the rise of darkness over light, such as the Summer Solstice. The Summer Solstice is when the length of the day starts to get shorter, most likely carries a magical significance on its own, and often falls on June 24, in the old Julian calendar. June 24 is also the date on which the third task of the Triwizard Tournament took place, and I don't have much trouble seeing the wizards refusing to adopt the new calendar.

As for why Voldemort didn't grab Harry earlier, well, he's still weak and Harry is under the protection of the only wizard Voldemort has ever feared, who likely has who knows how many tracking charms on Harry, and has a phoenix that can teleport through all known wards, including the those of the Ministry, Hogwarts, and the Chamber of Secrets.

The house-elves' "clothes" are cursed.
House elves being powerful magic users themselves—perhaps even more powerful than wizards—it's easy to see wizards wanting to do everything possible to keep elves from challenging their dominance. We know they denied them rights, treating them as animals despite having human-level intelligence; we know they didn't allow them to use wands, which would amplify their magical powers as it does for wizards. It's not too much of a stretch to imagine that they went as far as orchestrating the elves' magical enslavement, via forcing them to wear clothing which had a passive form of the Imperius Curse on it (the house-elves' enslavement resembles the Imperius Curse quite strongly—compelled to obey one master, an inappropriate sense of happiness, some can fight it with effort). The cursed clothing is so unlike actual clothes so that wizards could tell the crucial difference between enslaved elves and ones who were still free agents.

Ron is immune to the Killing Curse.
In the seventh chapter of the second book, Malfoy calls Hermione a Mudblood for the first time, and Ron tries to cast a spell at him. This spell is described as a jet of green light. Avada Kedavra is also described as green light. Therefore, Ron obviously tried to murder Malfoy (who was very lucky that Ron tried to do it with a broken wand). When it rebounded on Ron, it merely caused him to vomit slugs. Thus, Ron bears inherent magical protection from the Killing Curse (and possibly other curses as well), turning it into something much more harmless when used on him.
 * ...spells aside from Adava Kedavra can be green, y'know.
 * Hey, it's a WMG; just go with it!
 * That doesn't protect it from being outright stupid.
 * So, a twelve-year-old wizard with no apparent interest in the Dark Arts and no special talent for dueling managed to cast a silenced Killing Curse? It's a damn shame he never got a chance to duel Voldy.
 * Two problems with the theory: there's a specific name for the slug-vomiting curse in question, it's called Slugulus Eructo. Second, in the movie, Ron even says outright "eat slugs!"

The Potter Verse will become an Unmasqued World following Voldemort's fall
The Tales of Beedle the Bard is clearly written for both a muggle and a wizarding audience, and was published after the events of DH. It was supposedly translated by a (presumably adult) Hermione Granger and makes several references to the "most recent wizarding war."
 * The unmasque-ing will start when the vampires reveal themselves, although it'll apparently take a long, long time before all the other beings are believed.
 * Actually, The Tales of Beedle the Bard are edited by Dumbledore, so he is referencing the first wizarding war.

Dumbledore is a phoenix animagus.
This was here before, a rather in-depth explanation too, before the Data Vampires or someone who liked deleting things they thought weren't taking the WMGs seriously trust me, it was serious), but what I can remember was this: Mostly, the ability to teleport even on Hogwarts grounds, in a puff of fire in the books and fifth movie, as well as how he tends to take his time travelling (possibly flying places as a phoenix instead of going on a broomstick or apparating instantly?). There are at least four unregistered animagi in the books, and at least three of them figured it out during their early school years without detection, so why not the Greatest Wizard of All Time? There was more, so if anyone remembers it, could you please post it?
 * Related WMG: Fawkes was Dumbledore's mate. In settings where there are more than one phoenix, they usually mate for life, and Fawkes headed away never to be heard from again once Dumbledore died. If it was human-level sentience, like the merpeople (which Dumbledore could speak the language of), then bestiality wouldn't be a concern, and the animagus ability would act as the Male To Phoenix Universal Adaptor, if they even did anything like that. If phoenixes aren't human-level intelligence, Fawkes could have imprinted on Dumbledore in his phoenix form, and it just didn't go away when he turned back into a human.
 * So does that mean that Fawkes is actually Grindlewand? He was searching for the Deathly Hallows as a way of cheating death and along the way discovered that he was a phoenix animagus that allowed him to be "reborn" as it were.

Animagus are chosen by wizards as avatars of their personality.

 * Prongs was too good a pun for the womanising James to pass up so he became a deer.
 * Grindlewand was a phoenix (see above)
 * Hang on why would Peter choose to be a rat, hmm? If I were only hanging out with Marauders (and later Death Eaters) because it was convinient for me I wouldn't blow my cover with a massive anvil like that.
 * My subtheory: Potter screwed him over, by convincing Sirius to help him keep Remus from stopping their prank to carefully guide Wormtail's transformation-activating sequence into him becoming a rat animagus. It's more likely, though, that they needed something wolflike (moddhey dhoog), something that can hold back a wolf without dying of blood loss (anything with large, branching antlers that stick up instead of out like an elk or forward like a caribou), and something that can deactivate the whomping willow in case it grows too big for them to use a stick (cat or [if sapient species count as the animal form, see phoenixes above] kneazel would have been better, but that's just my opinion, they may have wanted something that could crawl amongst the roots in exchange for a decrease in speed).
 * Word of God says that wizards have no control over their Animagus form (or what shape their Patronus will take); it reflects their deepest personality. Which still doesn't explain why the rest of the Mauraders never suspected that Peter might betray them.
 * Maybe because they weren't following the idea that =teh evil!!!!1!!!!, but rather other things about  ? i.e. intelligence for example?
 * Agreed, domesticated rats are known for intelligence, cleanliness, and the strong bond they form with their owners.
 * Fridge Brilliance. Wormtail did 'rat' on the good guys.
 * Also consider the things on the Maurader's map - this includes not just classrooms, teachers offices, dorms, and other rooms that the boys might have been able to access in human form, but also presumably teachers private quarters which they would not have had access to and would have been in very very serious trouble if they were discovered in. Add that to the secret passageways - well, they had to find out about those somehow, right? And you can bet they didn't just happen to guess that the humpback witch was a secret tunnel, Peter probably discovered it in rat form. It's a crumbling tunnel underneath a statue, there are probably cracks or small holes that a rat could hide in but it's pretty damn hard to come up with a reason they'd have just happened across it.
 * In China, rats are known for shrewdness, cunning, and foresight- traits that could be positive or negative, depending on the person, so that sounds about right.
 * And it also seems that the animagus form is really a reflection of the core of the person - their biggest, best self - a potential that hasn't necessarily been realized yet. Sirius' animagus form is a dog because of his loyalty and capacity for love, but as a human being he has a lot of traits that don't reflect this - grudges, bitterness, and a willingness to hurt others (even those he loves, like Harry). Likewise, what we see of James does not reflect traits commonly associated with the symbolism of the stag. But they both have the potential to embody all of the good things about these animals, and the same is true for Peter - he COULD potentially have embodied the intelligence, craftiness, and loyalty that domestic rats display. But he didn't. The closest thing we see to a person really fully embodying their animagus form is in McGonagall, which may have a lot to do with her maturity.

The Rule of Seven Voldemort was going for would have worked if
His soul was in seven pieces, but the way I misunderstood the first time I read book six was that he should have had seven horcruxes, aside from the central soul that was powered-up by them. When he killed Harry's parents, not only The Power of Love saved Harry, but the fact that Voldemort had completed six horcruxes and his spell was straining for a seventh was what caused him to. Because of this, instead of one soul in the human and seven fragments forming a metaphorical septagram around him, it was one soul in the human, six fragments looking for the seventh point, and after the lashback, became. The end of Book Four just confused things even more.


 * When he went after Harry, he had made 5 of the intended 6 horcruxes: Diary, Ring, Diadem, Locket, Cup. He was going to kill Harry and make his 6th. Died, without realising it.  In Goblet of Fire, he made Nagini into what he thought was his 6th Horcrux, and was actually his 7th. So really, he achieved the Rule of Seven simultaneously with his fall.
 * When he went after Harry, he had made 5 of the intended 6 horcruxes: Diary, Ring, Diadem, Locket, Cup. He was going to kill Harry and make his 6th. Died, without realising it.  In Goblet of Fire, he made Nagini into what he thought was his 6th Horcrux, and was actually his 7th. So really, he achieved the Rule of Seven simultaneously with his fall.

Horace Slughorn has dabbled in dark magic, and actually wanted Voldemort to become a dark wizard.
Consider Horace 'letting slip' the information about the horcruxes to Voldemort. We know he enjoys having famous students, so what about infamous students? 'All publicity is good publicity' may have been one of Slughorn's mottos, or perhaps a good student is one that can do magic well rather then where their morals go. He knew Voldemort was something dark, and predicted he would go far. He sort of helped Voldemort along and expected to see a powerful yet questionably moral high ranked Wizard with slughorn to thank. What he didn't expect is Voldemort to get cult followers and declare a bloody war. Giving Slughorn still more to be ashamed of.
 * This would shed new light on Sluggy's initial reluctance to fight Voldy in Book 7.

The canonical series ends on page 657 of Goblet of Fire
In a Hofstadterean way, Rowling decided to conceal the true end of the series and leave clues so that a sufficiently assiduous reader would be able to find it. The kinds of hints listed in GEB (403) are: Now, Rowling said that Harry Potter would end on the word "scar". Furthermore, directly after this point we have the mix-up of the order of Harry's parents coming out of the AK. The series also slides into being far darker and edgier with the next three books, and there are several new characters and odd non-sequitur plot points introduced. The final canonical sentence, then, is "It was pain beyond anything Harry had ever experienced; his very bones were on fire; his head was surely splitting along his scar", and everything after that is left as an exercise for the reader as a sort of Bolivian Army ending.
 * A small but telltale feature that would signal the end
 * Extraneous characters or events which are inconsistent with the spirit of the foregoing story
 * A sudden shift in letter frequencies or word lengths
 * Errors appearing immediately thereafter.
 * The mixed up order of Harry's parents coming out of the wand was a publishing error that got fixed. this Tropers copy has Lilly coming out first and then James, which is the correct order.
 * Word of God (I think) said the last chapter was written first, hence why it seems so "amaturish".
 * Just a note on page number - the relevant page in my UK first hardback edition (with James emerging first frow Voldy's wand)is 570.

Salazar Slytherin put the basilisk it Hogwarts to protect wizards not hurt Muggle-borns.
He anticipated that Muggle weapons were becoming more dangerous a very fast rate and you feel a matter of time before they start attacking the wizards that were oppressing them.
 * This Troper actually read a very good Fanfic that used this theory (see the Fanfic Recs page for Harry Potter). When we first learned of the basilisk, it is mentioned that "...spiders flee before it." Yet we never see anything more than a few house spiders leaving the castle. When Harry  has to return to the Chamber to retrieve a Horcrux (Long Story), it has become overrun with Acromantula (what Aragog was). Harry deduces that Slytherin placed the basilisk there to protect the castle from being overrun with giant spiders.

Arthur Weasley is more competent than he lets on.
HE works in the department that is basically MIB for wizards keeping the locals from drawing suspicion not to mention the study work and trying to create great feats in magic and technology combination.

Hufflepuff House is actually the most dangerous one.
According to the Sorting Hat, Hufflepuff gets the students that are the most hard-working, loyal, and trustworthy. It would stand to reason that they'd be taught magic that's too dark to be entrusted to a Slytherin. They're tailor-made to be the black ops of the Ministry of Magic, and if one in a million of them do go bad, they never get caught. After all, who would suspect a Hufflepuff?
 * So while Aurors are like a cross between the CIA and Green Berets, and mostly come from Gryffindor, there's an even more secretive group of back ops members (possibly related to the Unknowables) comprised almost soleley of Hufflepuffs? Cool.
 * Tonks was a Hufflepuff. Hmmm.
 * So was Hogwart's champion, Cedric.
 * Also, their mascot is a flippin' badger: They seem all cute and cuddly and harmless... until they rip your face off. The honey badger is the most fearless creature on the planet, and can take bites from a friggin' cobra and all that happens is it takes a freaking nap, and goes right back to eating the cobra like nothing happened. Honey badger don't give a shit indeed. Nothing can stop them. Fear the Hufflepuffs. Fear them.
 * Alternately, they could make up the majority of the Unspeakables. If Aurors are the Black Ops of the wizarding world, then the Department of Mysteries' 'Unspeakables' would have to be something like Area 51. As Book 5 clearly shows, the Department of Mysteries deals with stuff that's abnormal even by wizarding standards, and they are sworn to secrecy. Note how Hufflepuffs are often the 'forgotten' house among the four. Not to say that a Gryffindor couldn't do the job, but Gryffs would probably tend toward being more on the frontlines. Additionally, one of the apparent 'weaknesses' of Gryffindor is that some of its members have a tendency to be brash, bullish, or even outright cocky.

The Mirror of Erised does tell the future, but in exactly the way that makes it look like a Mirror of Desire.
Harry does bring his parents back to stand behind him both literally and metaphorically, even if they aren't actually alive, and Ron overshadows his brothers both as a Keeper and a hero and gives much help in winning the House Cup in his first year. If someone wanted the Elixir of Life, they would likely see an image of them trying to find another way to make it and assume the potion they were drinking was a working Elixir, and people who don't have a future (through starvation or otherwise) would see, respectively, them seeing pretty images in the Mirror or heaven/and Ironic Hell (all that gold and nothing on which to spend it). If a perfectly content man looked in the mirror, he would see himself exactly as he was either because he was perfectly happy keeping his mind in the present (and thus not activate the mirror), or because the creator of the mirror thought that people with no aspirations have either no imagination, no future, or both. Harry sees himself with the Stone because he's about to have the stone, and Quirrel sees himself about to present the Stone to the Dark Lord because he's about to present the stone to him (even if it is still in Harry's possession at the time), or because he's seeing a future production of A Very Potter Musical and is presenting a different kind of stone.
 * Jossed by Rowling stating that Voldemort would see himself all-powerful and eternal and Dumbledore would see his family alive and well.

Voldemort is Haploid
Did you expect him to use his filthly muggle father's genes forever? Before he could garner the loyalty of pureblood fanatics he had to purify his blood. He wanted to anyway. Unfortunately, this left him with only a single set of genes (and a rather inbred one). He patched over the worst bits with snake dna. What he couldn't replace was the Y chromosome. Ever since the transformation, he's had no testosterone. This is why his voice is so high pitched. It also partially explains his obsessions. He can't have children, so the Slytherin line ends with him, so he must live forever. He can't truly be a man, so he must conquer the world and grind it under his heal.
 * So, after he purged his father's DNA from himself, he became a biological female with Turner syndrome.
 * Inheriting your mother's genes does not automatically make you female. Purging the DNA inherited from the father would not automatically female. As long as he retains his Y-Chromosome in his gamete, like what the OP mentioned, he would still be male

The creatures that Luna believes in are all Eldritch Abominations that only she can see
Her mother's experiments were attempts at seeing into the other dimensions and planes of the universe. When the experiment went awry, Luna was present and her mind was altered so that she is constantly seeing both our world and the various other layers and dimensions of the universe. Unfortunately, this has taken a toll on her mind and she has some difficulty differentiating between the reality of the creatures and such she sees and the fantasy of the various conspiracy theories her father comes up with.
 * Alternatively, her father can see them too, its just that nobody other than the two of them can. Everything in the Quibbler is true... somewhere. The Lovegoods simply can't distinguish there from here, since they see it all.
 * Lovegood. Lovecraft. Allusion win? Then again, if poor Luna is seeing Shoggoths in the third floor bathroom...

Gilderoy Lockhart is a Muggleborn.
At the end of Chamber of Secrets, after his memory is erased and Fawkes is getting them out of the Chamber, he screams something to the effect of "Amazing! It's just like real magic!" Except that if he'd grown up knowing about magic, he'd assume it WAS magic. He still knows how to talk, and presumably he'd been exposed to magic before learning to speak enough times that it was an accepted part of life by then, so you'd think that if he'd grown up in a magic household, he'd remember the existence of magic. Since he didn't, it can be assumed that he was a muggle-born. -This could explain his whole bragging schtick-he has an inferiority complex. He was teased mercilessly while at Hogwarts as a student, especially if he was a Slytherin, so he grew up with a need to prove those people wrong. He wasn't sure how to go about doing that so he just ripped off stories from a bunch of other people instead.
 * I'd assume he was a Squib. It's not accidental that we are introduced to the Magic Course for Squibs (or whatever it's called) in the very same book Lockhart appears.
 * But the original argument still stands because squibs are born into magical families and raised around magic and if he were a squib, he'd never have been able to do all those memory charms, especially not the one so powerful that when it backfired, he lost all memory of who he was but could still sort of function. If that's what he was intending to do to Harry and Ron, that'd have taken some finesse.

The evil plot in The Goblet of Fire made sense...if you're Voldemort.
Voldemort needed "blood of the enemy, forcibly taken." That means the victim had to be conscious and resisting. Any adult wizard would be likely to know a way to disrupt the ritual, and Voldemort couldn't take that risk. So it had to be someone young. Voldemort is proud, and insisted that the blood that resurrected him, that would henceforth be flowing in his own veins, must be that of the most worthy young wizard in Europe. Hence, kidnap the winner of the Triwizard Cup. Now, Harry sort of gets "points" for being his archnemesis and having blood with special properties, so Crouch was instructed to give him enough help to ensure he at least made it to the final challenge. At the last minute, Voldemort investigated the contenders and decided he didn't want Fleur or Viktor to win: no filthy mongrel part-Veela blood for him, and Viktor's loyalties were in question: if he turned out not to be Voldemort's enemy, the spell wouldn't work! Crouch was instructed to take the two of them out, but leave in Cedric as the "spare" in case Harry proved unworthy in the maze.
 * "Kill the spare!"

Fang was adopted when he was more than a puppy.
Fluffy: Got him when he was a small pup (emphasis on "small", considering Fluffy is a Cerberoid). Cutesy Glurge name. Norbert: Got him when he was an egg. Moderately cutesy name. Aragog: Got him when he was an egg, but 'e named 'imself, didn't 'e? Fang: Acquisition undocumented. Most specific reference leads only to "not full grown". Chompy name. Conclusion: Fang was already named when Hagrid got him.
 * That or Hagrid has a bit of self-awareness with his ironic nicknames, and gives the most intimidating name to his least intimidating pet.

The reason for all of those empty classrooms and that there are maybe eight teachers for the entire school, ten or twelve if the AP classes get their own specialist?
There used to be a lot more teachers, and probably but not necessarily a lot more students, but most of the teachers would have been involved with the wars against Grindlewald and Voldemort. Especially since they and the best students would be most likely to join the Order of the Phoenix or the Aurors, who had the highest death rates during the last war, many of Hogwart's faculty ended up dead during the forties and seventies. There are so many spare rooms, not just because of fluctuations in population over the thousands of years Hogwarts was probably planned to run (Chaos Architecture could have solved for that, and probably did), but also because many of the classrooms were places to hold other advanced and optional classes, and split up the houses into their own classes instead of having doubles classes all the time. In another few decades (or more, since wizards live so much longer than nonmagical humans and thus require longer to be considered a master of a craft), they might be able to hire up more teachers, split up the doubles classes (or put doubles classes on a rotating schedule, since it probably encourages inter-house fraternization), and go to having a Defense Against the Dark Arts curriculum with multiple specialists who teach shorter terms instead of a single teacher giving completely different aspects of the DAtDA lessons each year.

• That completely makes sense, when you think about it: comparable to the "lost generation" in post-WWI France (an enormous hole in the population where all the young men who should have been starting families were dead); considering that the books suggest the first war went on a lot longer than the second, the entire Wizarding population might be a lot smaller than it ought to be (which would explain a lot in and of itself, like how almost every adult seems to know one another).

Or they're not classrooms. Don't forget, Hogwarts was founded when witch burnings were a reality. So given that Hogwarts is a CASTLE which are typically built to hold off invading armies, which magically defenses, it's entirely possible that it was built to fit as many people as possible just in case. If you're gonna hide in magical castle from the crazies wanting to burn you alive, you would want some room and not be crammed into very limited space. Or it could both this possibility and the one above. Who says there can only be one explanation?

There is no curse on the DAtDA professorial post, it was planned that way.
The reason that no teacher has held the job for more than a single year in a row since Tom Riddle asked for it is because no teacher has held the job for more than a single year in a row since the class was founded. Instead of trying to find one, decent, well-rounded teacher and teach a little bit about lots of things each year, they hire a new specialist each year and work on a five to seven year cycle of subjects (GenEd, Specific Spell Defense and Charmbreaking, Mythical Creatures above level 3 [and thus not suited for Care of magical Creatures], Paranoia [defense against general spells and scrying]...) Maybe there was a Poison and Mind/Body Altering Substances Defense subclass, but it got absorbed into Potions and Snape got locked out of the job he became potions master to get to. Lockhart not doing his job and the war and job snatchings going on from book five onwards probably screwed up the curriculum a bit.

Only the cool families, like the Blacks, Prewetts (hence the Weasleys), and s get vaults at Gringotts.
Everyone else just has to make do with the usual "give the goblins your money, get credit for an equal amount" deal, but since you have to be physically present to withdraw from your account, there's no inconvenience of having it in a vault along with your other valuables instead of opening a checking account (beyond personal IOUs to people who know you're good for it, of course).

Ariana Dumbledore received brain damage from the beatings.
That's why she was "never the same" afterwards. I don't really remember the rest of the situation, but based on comments further up the page, don't you think someone breaking his daughter's skull when trying to stone her to death would be a sufficiently Azkaban-worthy reason for vengeance for Dumbledore Sr.? Especially if she had a shield like Neville, when he fell out the window and bounced, so they'd probably keep going bigger and bigger with the intent to inflict pain and/or injury until something broke through as she showed more magical effects.
 * While I do like this explanation, I think that the wizards could have fixed it. Brain damage is physical, not psychological. It does influence a humans behaviour, but in this case, a physical wound would have been the cause. I'm pretty sure a wizard could reverse a lobotomy, for example.
 * We went through this with the glasses thing. Brains, like eyes, could be "difficult".

Fred and George are Fabian and Gideon reincarnated
Shortly after Fabian and Gideon were killed in battle, Molly found out that she was pregnant. Before they were truly inhabiting their new bodies, their souls inspired her to sorta, kinda, partially name the babies after them, by giving them the same initials. Many a fan has postulated that Fabian and Gideon were spiritual predecessors to Fred and George (i.e. massive pranksters during their Hogwarts years), this is just taking it a step further.

Snape is Voldemort's son
Actually, the more you think about this the more sense it makes: Voldemort raped Eileen Prince during his "absence" from the Wizarding World. Eileen then married Tobias Snape to save face and pretended that her child wasn't the spawn of Evil Incarnate. Tobias, who was never sympathetic anyway, convinced himself that his wife was a slut and hated Severus for being another man's child. Tobias's hatred of Severus also explains adult Severus's jealousy issues with Harry and Lily. In addition, Severus Snape is shown to be an extremely powerful wizard, on a level with both Dumbledore and Voldemort in the last two books; he showed a knowledge of, and talent for, the Dark Arts by the age of eleven, he's intelligent enough to invent his own spells, he's the most accomplished Occlumens of his time (to counter-act his real father's aptitude with Legilimency), and in the seventh book, he uses spells that are described by other wizards as being the type "only Voldemort" would use. In book seven, Voldemort figures out that not only is Severus his son, but is also a more powerful wizard than he is, and kills him out of fear, rather than a desire to conquer the Elder Wand. ...You're still squicked out by the idea of Voldemort naked, aren't you?
 * Depends on which Voldemort you're talking about.
 * Book!Voldie.
 * To be fair, he would not have been a snake monster at the time.

Snape picked on Neville because...
Lily died.

The rationale is simple: Snape knew that the prophecy had two possible candidates for the "Chosen One": The Potters and the Longbottoms. If Voldemort had chosen the Longbottoms first and been brought down, Lily doesn't die sacrificing herself to save her child. So Snape hates Harry for being Mini!James and Neville for living while his Lily had to die.

We'll ignore the parts about this meaning James is still around as well or that this means Bellatrix goes after the Potters instead of the Longbottoms. Snape isn't the most emotionally logical person around.
 * ...Are you sure that's not canon? Because it should be.
 * Just because a theory is on this page doesn't mean it might not be proven right eventually. Yes, a lot of the ones on here are purposefully silly in nature but a few seem pretty serious, and this one is one of the more logical and likely ones. Though I might just be sticking up for this one since I believed it, too...
 * Snape may have also had a grudge against Neville's parents, who were aurors. They may have met in battle, or they may have interrogated him with traumatizing intimidation tactics.

Harry was secretly working with Quirrell.
The events of the first book are Fake Memories (although very close to the truth). Harry, bearing as he did a little bit of Voldemort's soul, was an evil little bastard, hence why he was locked in a cupboard and abused growing up. Shortly before Hagrid's visit, Quirrell showed up, told him about his link to the Dark Lord, and asked him to be a sleeper agent, to which Harry agreed in exchange for a promise of power. He insisted on being placed anywhere other than Slytherin, and befriended people he knew he could manipulate. Harry and Quirrell each went after the Stone separately as a failsafe (with Harry persuading his friends to help by claiming Snape was after it.) Once they met up at the Mirror, they realized they needed a Memory Gambit in order to get past Dumbledore's spell. Quirrell memory-charmed Harry into thinking that events had occurred as in the book, which allowed Harry to get the Stone. The plan was for Quirrell to undo the charm as soon as he got it, but then Dumbledore showed up. Now, thanks to the charm, Harry was a good guy. The only person who ever knew otherwise was Voldemort, and without Quirrell's wand he couldn't undo the spell. Well, and the Dursleys, but their behavior is completely consistent with Harry being a devil child who once bit off the mailman's ear, and is now unaccountably acting nice.


 * There's no reason he'd need to have Quirrell's wand to undo a memory charm though, and if they'd been working together for a year it's likely that they'd at least notice the love protection on Harry and realise what that would do to they're plan and adjust accordingly. It also doesn't explain why everyone elsess memories match up with Harry's. Nice idea though...

On the Life-Cycle of Dementors and Lethifold.
As the dementor (the adult of its species) feeds on more and more fear and emotion, its cloak gets thicker and thicker, until the dementor preforms the Dementor's Kiss the outer layer of cloak (now imbued with the life force of the victim) sloughs off like a snake's skin at the next dark or secluded area. The part of the cloak that separated becomes a lethifold, which creeps into human homes while they sleep and eats them, deconstructing them and eventually (after the escape of the sated lethifold) reconstituting it into a sort of humanoid form within its body. It is possibly that the lethifold requires more than one average adult human to become a dementor, but based on the rarity of lethifold attacks that have not been proven to be hoaxes and the lack of density of a dementor's body, this is unlikely. While the increase in lethifold attacks in recent centuries may be due to an increase in the human population, and thus an increase in faked lethifold attacks, it is also quite possible that the increase in attacks is due to the constant feeding the dementors get at Azkaban, and the adoption of the Dementor's Kiss by the Wizard's Council and Ministry of Magic as legal punishment.
 * At least one problem of this is that Lethifolds are only found in tropical areas, needing warmth and humidity. Although I suppose you can just alter this theory to say that, like a snake with skin, a Dementor needs a warm, humid area to shed the Lethifold and can carry it around (uncomfortably) for awhile before that. A Dementor who has performed the kiss needs to head South as soon as possible.

The snake that escaped from the zoo at the beginning of Philosopher's Stone was actually Voldemort
Think about it. Voldemort had the ability to turn into a snake. After he killed James and Lily (and turned Harry into a human horcrux) he went into hiding as a snake and ended up at the zoo. The day Harry was there, Voldemort recognized him. He decided he'd been in hiding long enough and escaped. Harry didn't actually set him free, he just thought he did. After Voldemort escaped, he found Quirrell and took up residence on the back of his head.
 * Word of God said it was Nagini, if this troper remembers correctly.
 * No. Word of God never said that... that snake was just a snake. It was a pretty non-evil one as well.

Squibs are a little more magical than Muggles
Muggles can't enter Hogwarts. Filch, who is a Squib, works there, so he obviously can. Squibs are probably able to see things Muggles don't see. They may also have some sort of ability to communicate with animals, especially cats.
 * Wasn't this um confirmed in the books? And even so this doesn't seen like WMG so much as stating the obvious

The points awarded to Gryffindor at the end of the first year were exactly equal to point spread taken away from Gryffindor and given to Slytherin, in Dumbledore's opinion, unfair reasons.
Taking points off for Potter being a Potter, Granger being a know-it-all, and Neville being easily panicked, and giving points to/not taking points from the Slytherins for being Slytherins and being Slytherins respectively really adds up over nine months.

Bellatrix Lestrange has a daughter
She was married, probably for a significant amount of time, and, when Narcissa is whining about Draco being made a Death Eater, she specifically says "If I had 'sons'..."
 * Thanks, I wasn't planning on sleeping for the next thirty years anyway... (Sorry, but I can't be the only person who is utterly terrified of the idea that someone like Bellatrix Lestrange would reproduce.)
 * Nope, you're alone on that one.
 * Hold it. I can make all of this worse. We never meet Bellatrix's husband. But who do we see her acting romantically around the most . . . ? (Hint: His name rhymes with Moldemort, and I have just given you nightmares.)
 * Sorry, but we do meet her husband - Rodolphus. in the "Goblet of Fire" Harry travels to Dumbledore's memories and sees Bellatrix and two other men appearing before the court. Later in the graveyard Voldemort says that Bellatrix and her husband are in Azkaban. And in "Order of Phoenix" during the battle in Mo M we hear Death Eaters calling Rodolphus' name - apparently, he's among them.
 * I think what they meant is we never really "meet" Rodolphus in the books besides some brief mentions and he does nothing of import but Bellatrix is a fairly large character for the series and spends her time being infatuated with Voldemort instead of ever interacting with her husband ever.
 * Helena Bonham Carter in the act of reproduction, and you don't want to see that?
 * Let's not confuse the actors with their characters, mmkay? See the very top of the page for the distinctions.

== James Potter got some Character Development  == That's why Lily fell for him. At first he was a Jerk Jock, but stuff happened and he grew as a person. Lily genuinely fell for the person James became, and he fell for her as well. She didn't fall for Snape because Snape had Character Development, but it was in the "wrong" direction. (Calling her names, using the Dark Arts etc.)
 * I love this theory for two reasons: One, people's personalities are never set in concrete, and if James wanted Lily badly enough, he would have changed and improved himself for her; and two, what if Voldemort had gone after the Longbottoms instead of the Potters? Snape wouldn't have had any motive to stop being a Death Eater or turn to Dumbledore, and probably would have ended up in Azkaban with Bellatrix, et al.
 * Uh, isn't this canon? That's what Remus and Sirius told Harry via flue in Order of the Phoenix when he asked them about it, that in his sixth and seventh year James stopped being such a jerkass. Possibly due to him reconsidering and stopping Sirius's 'prank' on Snape. (Sirius, OTOH, never seemed to change, at least not before Azkaban.)
 * Confirmed

Love potions are like any other drug when taken during pregnancy.
Only in the case of love potions, either because of the magical personality changer or some side effect involving it messing with the genes or developmental hormones, they turn the baby into a psychopath with strong risk of really wanting to be a snake demon (There's a WMG for you...).
 * J.K did confirm that being conceived under the effect of a love potion did affect his ability to love.
 * The pregnant person in question wasn't the one taking the love potion, her husband was.
 * Actually, intake of alcohol and other drugs can deteriorate sperm quality on the part of the sperm donor.
 * Didn't JK say that the circumstances of Voldy's conception were a metaphor for his loveless state, but not a cause of it?

Hogwarts is somewhat sentient.
The castle has over time used the enormous amount of magic inside it to form some sort of consciousness. It would explain why Dumbledore always seems to know everything that's going on there. The castle obviously does, and he - as the headmaster - is tied to the castle to the point where he knows what the castle knows.
 * I think this has been all but verified by Rowling.
 * I believe this theory, because if Hogwarts is sentient, who knows, it could an Eldritch Abomination, which make the story creepier, and I love creepy things.
 * At the least, the Room of Requirement is definitely intelligent.
 * You guys are gonna love this one...

Durmstrang is located in Russia.
It's in "the north". The only reason it remained (at least with its original name) through WWII was the adult Grindelwald's direct influence. Krum got in because his family was rich enough to send him there instead of a lesser school closer to home or a government-funded school like Hogwarts, and partly because he showed wicked promise as a Seeker even when he was ten (he was on the Bulgarian national team when he was underage! It's not much of a stretch), and they're sort of the Slughorn of wizarding schools (not necessarily in a bad way, though).
 * I have always sort of assumed that Durmstrang was in Bulgaria, since Viktor Krum went there and he's Bulgarian. But there is nothing that says you can't go to school in another country than the one you were born in (IIRC, Lucius Malfoy wanted to send Draco to Durmstrand even though they're British), so it could just as well be in Russia, I guess.
 * Seamus Finnigan is from the Republic of Ireland and attends Hogwarts, so wizarding schools don't seem to restrict entrants based on nationality. Durmstrang being in "the North" rules out Bulgaria though, which is quite considerably south (borders with Greece and Turkey!): the only Slavic country north of Hogwarts's Scottish home would be Russia. Add the year-round fur coats and the fact that the only other named students have Russian names and there's a strong case.
 * The name "Durmstrang" doesn't sound Russian (or Slavonic, for that matter) at all to me. Looks more like a German (or Germanic) name. It could be located in Scandinavia or Greenland (former part of Denmark).

In addition to dark magic, Durmstrang is an academy of Modern Dance.

 * This explains their beautifully choreographed introduction in the GoF movie. It's in Eastern Europe, well known for producing fantastic ballet dancers. And the total control of one's body developed by a dancer would probably to wonders for a person's wandwork.
 * I think you've gotten that mixed up with Beauxbatons, which is in France. Durmstrang comes out and does some stuff with staff. I've always wondered what Hogwarts would do. A perfectly-choreographed pantomime of a student being put in mortal danger due to whatever dark secret's lurking around the place that year?
 * Maybe Hogwarts is just the ghetto school.
 * Beauxbatons did a well-choreographed intro in the book, but in the movie they basically just walked around and sighed. Durmstrang's wasn't exactly a ballet but it was more impressive.
 * Or maybe they teach magical martial arts. Kind of odd for a school most likely located somewhere in Russia, I know, but perhaps someone from a border town near China brought it over?
 * The Harry Potter universe is the future of the Avatar: The Last Airbender world, and Harry is the most recent incarnation of the Avatar.

In the films, Voldemort customized his wand
There's simply no way Ollivander would create the overtly evil looking wand Voldemort wields in the films, let alone put it in the hands of a ten year old. The only explanation is that movie Voldemort customized his wand, or that it was altered by the nature of the magic he performed with it.
 * That is entirely plausible, actually. IIRC, at one point Ollivander says something about Lily's "first wand", which seems to imply that people generally replace their wands from time to time. A lot of things can happen to a wand, they are after all made of a thin piece of wood, and their owners usually keep them on their person at all times. It wouldn't be that far fetched to imagine that Voldemort lost his first wand (especially since he spent quite a long time without a body) and had to get new one, which also makes it easy to belive that he customized it.
 * It's plausible he customized it, mainly the handle, but the idea that he lost it completely and replaced it with the macabre-looking one from the films contradicts the priori incantatem factor which becomes a huge, plot-revolving point in the fourth and especially seventh books. Whatever the handle looked like over the years, the wand Voldemort uses to after being resurrected is outright proven to be the same wand he killed the Potters with and was sold to by Ollivander, with a two-of-a-kind phoenix-feather core, as a child in 1938.
 * The "Tom Riddle's Wand" page on the Harry Potter wiki says that the wand Riddle got from Ollivander's before he joined Hogwarts explicitly had a handle that appeared to be made of bone. Then again, the page also looks like a Self-Insert Fic with the wand as some sort of Mary Sue that keeps turning up every freaking time something related to Voldemort happens ("used his wand to create [a horcrux] using his childhood diary through the use of his earlier indirect murder of fellow student Myrtle by means of the Basilisk of the Chamber of Secrets", "continued to perfect his use of the Ollivander wand until he graduated from Hogwarts in 1945"), so I doubt its veracity.
 * I never doubted that this was the case. Lucius also has the metal snake-head wand handle and pimp cane sheath. I always assumed that you could go to Ollivander (or lesser wandmakers/wand-customizers) and have your wand fitted with a new handle, strained, carved, bent, or other various cosmetic differences we see in the film.

Sunshine, daisies, butter mellow, "stupid fat rat" was turned yellow.
...in the sense of cowardly, rather than the sense of a 570-580 nanometer wavelength. This is why Pettigrew was so cowardly and weaselly (instead of merely a brave yet wrong-sided double agent) despite having been accepted into Gryffindor; He had been turned "yellow" by the spell Fred and George gave to Ron.
 * Another possibility is that the spell only works on real rats.

Harry and Voldemort are related.
Harry's a descendant of Ignotus Peverell. Marvolo Gaunt had the ring, which he claimed was passed down in his family. The ring belonged to the brother of Ignotus (Cadmus Peverell). Ergo, Harry and Voldy share an ancestor.
 * ...Yeah? That's how genealogy works. However, see next guess...
 * Well, yeah, I know it's kinda obvious, but since it's never really been mentioned anywhere else, I just assumed that most people didn't make the connection. So here I am, clearing it up.

Harry is descended from Salazar Slytherin.
Salazar was an ancestor of Harry's and Voldemort's common ancestor. James Potter, Tom Riddle, and Harry Potter were the last living descendants of Salazar Slytherin until 1981, which makes Harry's lack of wizarding relatives a plot point for the second book. This is part of why the Sorting Hat was so adamant about Harry going into Slytherin, because it Wouldn't Do to have the Heir of Slytherin (who was only coincidentally a Parselmouth) in Gruffleclaw.
 * Well, it is pretty much solid fact now that the last common ancestor of all Europeans lived 1,000-1,500 years ago. So...
 * I think that they had the same ancestor, but it was through the Peverell brothers. I also thought that Godric Gryffindor was the descendant of Ignotus Peverell, and James (later Harry) was a descendant of Gryffindor; meanwhile, Voldemort is confirmed to be a descendant of Salazar Slytherin, who I think is also a Peverell descendant.
 * Word of God: Harry could not speak Parseltongue . Therefore, he cannot be a descendant of Slytherin. He is still related to Voldemort through the Peverell family, because the second brother's descendants married into the Slytherin line, and the third brothers descendants married into the Potter family.

The Dark Lord his Eternal Somethingness Lord Voldemort found the Chamber of Secrets because he was being a pervy little... perv, as a kid.
One day, while spying in the girls' bathroom and using his pet snake as a sort of makeshift periscope/lookout, or as part of a prank, he told it (in Parseltongue, so it could understand him and any girls in the room couldn't hear him) "Open the door". As soon as he said "open", the Chamber opened.
 * This seems unlikely because of the impression given in the books that Voldemort was celibate.
 * Bellatrix's behavior towards Voldemort does reek of Unresolved Sexual Tension.
 * On the other hand, being a dirty-minded youth doesn't preclude someone choosing celibacy as an adult - and since young Tom was good at hiding his true intentions, few if any people would know if he was a perv. Maybe he grew up to decide sex was too much of a distraction (or read enough of the Evil Overlord List to know not to risk reproducing).
 * It seems more likely that Tom Riddle discovered the chamber because of his Parseltongue, not that he discovered it by chance as a happy coincidence. It is unclear how parseltongue works, exactly; Harry can hear the basilisk speaking when he's in its general proximity, but it doesn't seem to rely on actually hearing the snake. Other people with Harry don't hear any hissing or spitting when he hears it speak, on top of which it is traveling through the pipes so is separated from Harry by both a stone wall and a metal casing. This implies there is a mental or telepathic component to the skill, which Harry doesn't know about because he doesn't research the parameters of the ability nor does he try to develop his own ability any farther than what comes naturally. He relies on verbal communication with snakes in the same way he relies on verbal spellcasting even though it is possible to use magic without speaking. Tom Riddle was much older than Harry when the chamber opened for him, and he was also much more studious and interested in Dark talents which would be associated with Parseltongue even though the ability itself is not Dark. When Tom discovered he could talk to snakes he would probably have done all the study necessary to take full advantage of it, likely expanding the range in which he could detect snakes and potentially developing the ability to communicate with them nonverbally, allowing him to communicate with it through the walls. It must hunt sometimes and it seems it is only let out of the chamber in order to actually confront students, not just to access the pipes. Tom must have heard it at some point and realized what it was, and taking the opportunity to ask the basilisk itself how to get into the chamber. Of course, that would bring up the question of why Harry didn't hear the snake in his first year, as it was already there then.
 * The basilisk wasn't in the pipes until the Chamber was opened.
 * That we know of. There must be some method for the Basilisk to move about on its own without the help of the wizard controlling it. Eventually prey animals would stop going into the chamber area and it would need to be able to feed elsewhere. There may have been pipes built specifically for the Basilisk by Salazar Slytherin himself to allow it to move around, especially since most normal plumbing wouldn't be large enough to accommodate an animal of that size. Ginny Weasley opened the chamber which allowed the Basilisk out of the pipes and into the school, which is how it was able to see its victims face-to-face. It also seems to have been able to return to the chamber without her assistance, suggesting a direct connection between the pipes and the chamber somewhere. It's also possible that the Basilisk typically hunts at night, which would be why Harry may not have heard it until it began breaking habit in order to attack students on Ginnymort's command.

The American School of Witchcraft and Wizardry has been somehow sealed away by the Men in Black, SCP Foundation or some other equivalent
This explains why no American wizards/witches turn up in the course of the stories; they can't escape from the containment.


 * Two American witches are seen at the Quidditch World Cup in GoF. It's blink-and-you-miss-it, but they do appear.

Fewer magical children than usual were born in 1980.
Word of God states that there are approximately a thousand students attending Hogwarts at any given time. If all years has about as many students as Harry's does (namely eight Gryffindors, nine Slytherins, ten Ravenclaws, seven Hufflepuffs and three students whose houses are unknown), that would only make give or take 260 students all together. However, Harry was born in 1980, when the First Wizarding War peaked and Voldemort was more powerful than ever. Maybe the number of children born into magical families decreased drastically during those last few years of the war, because wizards who under different circumstances would have wanted children chose not to have any. They were, after all, practically living in terror by then, and the future of the wizarding world was uncertain at best.
 * Word of God also has admitted that math is not her best subject, and later said that only about 600 students are at Hogwarts in any year.
 * Which still doesn't add up. A total of 600 students would make about 21 students per House and year. Even I, who can freely admit that math is not my thing, figured that out without any problems.

Snape lives!
"I can teach you to bottle fame, brew glory, even stopper death."
 * Except the word is stopper, not stop. To stopper death is to put a stopper in it—like a cork in a bottle. I always saw that phrase as his saying he'd teach his students to make poisons.
 * In fact, the Nagini's venom was one of the last ingredients needed for his resurrection potion, and he'd planned it from the start.
 * Unfortunately, it isn't without flaws, and he spends the next book in a mindless frenzy " STARS Aurors!"
 * Harry Potter 8: Snape's Revenge!

There are a disproportionately high number of Muggleborns and Squibs in Ukraine
One word: Chernobyl.
 * Mind....blown...
 * Like Chernobyl.
 * And, by extension, Belarus. Heck, the whole area might be lacking in wizards.

The Salem Witches' Institute organized the pressings and witch dunkings in and around the original Salem.
What better way to cast suspicion off of yourself than to get people riled up about someone with your group's name but a different description, and take care of the Muggles with Muskets coalition once and for all?

The Salem Witches' Institute was the magical equivalent of a battered women's shelter.
To allow recovery from physical and emotional abuse while working to prevent stalking from being an issue, as well as recovery from such things as love potion detox.

Snape deliberately burned his bridges with Lily, as the first step in establishing his cover
Hey, he was willing to kill his (maybe friend) and handler, the only one who could or would testify to his mole-status.
 * It does seem uncharacteristically...stupid, for Alan Rickman a schemer like Snape to let rip with a racial slur.
 * This... Is not a WMG; it's just plain stupid. Let me count the ways: When he called Lily "Mudblood", did it not occur to the OP that he'd just been humiliated in front of the entire school and, being an angry and insecure teenager, was speaking like someone who was angry and humiliated? All There in the Manual, dude. Second, Snape is not a Seer; he had no idea he'd turn spy for Dumbledore within five years. For that matter, he didn't know he'd be Voldemort's spy and apply for a teaching position at Hogwarts in that timespan. Again, All There in the Manual. Third: Alan Rickman is not Severus Snape, and Severus Snape is not Alan Rickman. Just because Rickman wouldn't do something doesn't mean that Snape wouldn't. One is a fictional character, the other is an actor playing a fictional character. This doesn't need to be in the manual; it's just common fucking sense.
 * Unless, of course, becoming a spy was his plan all along. We only know what Dumbledore claims are his reasons for turning against Voldemort. Maybe he had others.
 * You're not getting it. He planned on becoming a Death Eater, that was it. Death Eaters are Mooks; they do whatever Voldemort tells them to. Whether or not Snape wanted to become a spy is beside the point (and he very likely didn't; a spy would have been the single deadliest position for any Death Eater if they didn't know Occlumency, and the only reason Snape did was because Dumbledore taught him). As for turning against Voldemort for other reasons... Like what? His boundless, burning passion for teaching all those wonderful, beautiful little children at Hogwarts how to brew potions? Also, this guess is based on the idea that "Snape is a schemer". He isn't. He's intelligent, but as our Idiot Ball-toting Big Bad could tell you, an intelligent person isn't guaranteed to be a master planner (and it doesn't take intelligence or a master plan to want to stay alive; that's called "survival instinct" and all living things act upon it). As for Snape being "willing" to kill Dumbledore? What the hell book did you read?! Dumbledore had to force Snape to do it by telling him he needed to make an Unbreakable Vow and all but making sure Draco failed to kill him! And please keep in mind that if Snape had just said "Fuck you, Dumby, I'm not doing it" and Draco ultimately failed to kill him, he would have died (again, that pesky survival instinct comes into play). He was right when he accused Dumbledore of using him; in the end, Snape was just as much Dumbledore's pawn as Harry.
 * He would have called Lily a mudblood because a Slytherin (and, as he hoped to be, future Death Eater) being defended by a Muggle-born after being humiliated by Gryffindors... well, yeah.
 * Jossed

Had Harry died before Voldemort at or after the end of the fourth book, Voldemort would have eventually gotten Harry's body without the need for a resurrection spell.
Assuming  (rather than or in addition to whatever technicality Word of God seems to say is the case), his corpse would have had the same inherent protection as   and been immune to decomposition (Harry's life was the only reason he kept growing and possibly was able to become ill). Under the premise of the guess,. On a related note, see the next guess:

Two of the had already been used up by the time Tom Riddle's diary was destroyed.
The first two were used up the nights Voldemort and Quirrell died, and all that remained was the protective charms that Voldemort had placed on them rather than any inherent protection. I'm thinking the ring was one of them, and the locket or an earlier snake was another, either because Voldemort put them back because they were important anyway and he wanted to get some use out of the traps, or because he thought they could still be used. If the second one was the locket, he might have been rescued by Pettigrew before getting a temporary body and was told to put the locket back (without specifying where it should have been) or got a blind piggy-back-ride inside Pettigrew (like Quirrell, but patched together instead of with added benefits like senses and external speech) before getting his temporary body.
 * I don't have a source on this, but horcruxes are not "used up" like extra lives in a video game. They way they work is simply that their very existence prevents the maker's (remaining) soul from leaving this world. Even if the person's body is destroyed, the soul remains — but the other horcruxes remain as well.

Hogwarts is bewitched so that all students are confronted with a mystery to solve each year.
This happens the same way the DADA teaching spot is cursed—it guarantees the teacher will be forced to leave after a year, but from completely external, logical reasons. In the same way, a completely accounted for and external mystery will present itself to every student. For example, a fellow student has a problem that he is hiding, and his friends spend the year figuring it out what it is. The books detail Harry, Ron and Hermione's particular mystery. All the other students are investigating similar, but much less consequential ones. This is why no seems to think it remarkable, bizarre, or huge news that the trio have these massive adventures every year—they're just wowed by the type of adventure, because their's are always more mundane. Possibly, one of James, Sirius, and Peter's was figuring out that Remus was a werewolf.
 * I suppose Ginny certainly had a mystery of her own in Chamber of Secrets. And what Malfoy went through in Half-Blood Prince might loosely count as a mystery.
 * This is my favorite WMG ever, and makes perfect sense.
 * If the school came up with Cedric's and Myrtle's mysteries, it's more Fridge Horror...
 * Those two failed to solve their mystery.

Tom Riddle Sr had a Muggle child.
When Merope was looking out the window at Tom Riddle, we hear him talking to his beloved, a Muggle girl by the name of Cecelia. Soon afterwards, Marvolo and Morfin are imprisoned and Merope gives Tom a love potion and runs off with him.

What we weren't told in the book is this: Cecelia was pregnant with Tom's child when he left her for Merope. When Tom broke free of the spell and returned to Cecelia, she was unwilling to accept him, as she still felt hurt and betrayed by his abandonment. She elected to raise the child herself, which is why the child was never heard from in the books. The child was a girl. Let's just call her Jane.

Jane grew up and married a man. Let's call him John Evans. John and Jane had two children: Lily and Petunia...

That's right. Voldemort is the half-uncle of Petunia and Lily Evans, and the half-granduncle of Dudley Dursley and Harry Potter. This also explains the physical resemblance between Harry and Riddle, which was mentioned by the latter in the Chamber of Secrets. Incidentally this theory means that Harry was tied to the gravestone of his own great-grandfather in Goblet of Fire.


 * The child would have been born about 1926, (Same as Voldy,) and that gives 34 years to have Lily who was born 1960. So the math works.

Salazar Slytherin's wife and/or family were burned at the stake by Muggle witch-hunters.
Hence, his anti-Muggle bias is not just bias, it is a personal grudge. Slytherin could not have been massively prejudiced all his life if he were best friends with Godric, the Muggle-Lover, and he would not have abandoned his best friend and his beloved school over a simple clash of ideologies unless the ideology was immensely important to him. Therefore, his anti-Muggle prejudice had to have sprung up sometime after he became friends with Godric and built Hogwarts. The huge fight between Godric and Salazar could have been Godric, fed up with Salazar's personal vendetta, telling him to stop being so obsessive, and that just because some Muggles killed the Slytherins, not all Muggles and Muggleborns were evil. Salazar would have countered that Godric was being naïve to assume that Muggleborns would be loyal to wizards, and also lash out at his friend for supposedly betraying him/not caring about him, unable to be reasonable because of his grief over his family.

The Flame-Freezing Charm was a huge humanitarian achievement.
Fire is generally accepted as being powerful in a magical way, therefore, it would stand to reason that it was not always controllable by magic. Witch-burnings persisted because they used to work—fire being one of the few things that witches and wizards could not defeat. The Flame-Freezing charm was invented sometime around the 1300's (hence the title of Harry's essay "Witch Burnings in the 14th century were completely pointless", not just "Witch-Burnings were completely pointless") and was hailed as a massive step towards ending persecution of wizards by Muggles.

The Weasleys are descendants of Godric Gryffindor.
Think about it—the Weasleys are a very old family, and according to the Blacks, one of, or possibly the biggest family of blood traitors alive. Also, the Weasleys are extremely well-known, and held in uniform derision by both dark-leaning pureblood families like the Malfoys, and high-ranking Ministry officials like Fudge, who spend their entire lives getting through one headache after another, all caused by Muggles. Godric Gryffindor was evidently a Muggle-Lover, probably something of an Arthur Weasley type, and it's likely that Slytherin's descendants, pupils, and veterans of his house would hold animosity towards Gryffindor. Plus, Gryffindor was portrayed as red-haired on Rowling's website, and was described as being from the moor—possibly Ireland. Finally, the Weasleys are perhaps the most perfect textbook examples of Gryffindors. "...where dwell the brave at heart. Their daring, nerve and chivalry set Gryffindors apart." They all have bravery, nerve and daring in spades—Arthur's crusading on the part of Muggles despite ridicule, Bill's willingness to work in his dangerous job, ditto with Charlie, as well as his athletic prowess, Percy's going against his family (brave, even if not honorable), Fred and George's daring with their pranks, Ron's various acts of bravery that are beyond his years, Ginny's ability to defy Tom Riddle, even temporarily. They have chivalry too—like Ron's continuous defense of Hermione and all the brothers' relationship with Ginny. All the Weasleys also have a general lack of concern about what others think of them or their choices—hence "nerve". And they have all the attendant negative characteristics that goes with bravery in varying degrees—recklessness, impulsiveness, stubbornness, bluntness, rudeness, sensitivity to slights, etc. In short, they do not lack any of the traits attributed to Gryffindor, nor do they have any very prominent traits that are not in-sync with what is attributed to Gryffindor. They are the perfect Gryffindors, perhaps not just by house, but by family line as well.
 * Good theory, but no way was Godric Gryffindor from Ireland. We don't have very many moors, and isn't Godric an old English/Saxon name?
 * Maybe he was half-Irish? And anyway, you don't have to be Irish to be a ginger.

House elves and goblins are of the same species.
House elves are simply a separate, more timid/friendly variety of goblin; or, alternatively, goblins are simply house elves born outside of slavery. Physical and mental differences between them (speech, thickness of frame, etc.) are a result of nutritional deficiencies on the part of the house elves. All of those goblin rebellions were house-elf rebellions, though most of them failed. From these extremely bloody failures, house elf culture has been built around their continued enslavement despite hardship and misery. While born free, goblins possess an extreme hate towards humans due to their continued mistreatment of their fellow whatever-their-collective-species-is. The goblin's notion of ownership reeks of this counter-culture: that the "maker" of something, not the "purchaser", can really possess an item.

J.K. Rowling works for the Daily Prophet, and Michael Gerber (author of the spoof series "Barry Trotter") works for the Quibbler.
Both "Harry Potter" and it's spoof, "Barry Trotter," were originally written for Wizarding audiences. Rowling is a witch, either a half-blood or a muggle-born. She originally wrote "Harry Potter" as a biography, after interviewing Harry and agreeing to help him set the record strait, after Rita Skeeter wrote her version of the events. The book wound up in Muggle stores by mistake, but no harm was done; everyone thought it was just another fantasy story. Rowling took advantage of this, and now markets "Harry Potter" both to muggles as fiction, and to wizards as non-fiction.
 * Alternately, Harry Potter was an Autobiography - Harry was created to protect Rowling's identity.

Comical Writer Michael Gerber, meanwhile, is also a wizard with some muggle relations. As such, he writes for a number of humor magazines, both muggle and magical—including the Quibbler. He wrote "Barry Trotter" to spoof Pottermania, but his muggle readers only get half the joke. His wizarding readers understand that he is spoofing not just Harry's biography, but also the way it became popular among muggles. But of course, the only wizards who even read "Barry Trotter" are the Slytherins, and Fred and George Weasley.
 * But... if the books were intended for a wizard audience, why do they spend so much time explaining the wizarding world and none whatsoever explaining any of the Muggle concepts so familiar to Harry? Especially in the first book, the wizarding world is meticulously introduced to the reader, explaining all the concepts that wizards would know anyway—but when the narrative mentions TV or computers or shotguns, things wizard would need an explanation for, no explanation is given.
 * Because it's spoofing the Muggles' perspectives of Harry Potter and the wizarding world. Note that the wizarding world Gerber describes is nothing like the real one; it's much sillier, and raunchier. The Muggle world, he doesn't have to change much, because Muggles are already hilariously pathetic to wizards.
 * Or, perhaps she accidentally sent it to a muggle editor, who wrote her back saying that the book had great promise, and he thought she could make a lot of money off of it, but he was puzzled as to why she was taking so much time to explain the functions of video games and electric kettles while leaving out so much about this fascinating magical world. JK figured it would be good reverse psychology (as per an example far above): propose to the muggles a world of wizards right under their noses, and tell them about ridiculously famous war hero Harry Potter as if he was a fictional character, which had the added bonus in that, if questioned about him, a wizard could always state they were talking about a book character. So she re wrote parts of the book to explain the magic instead of the muggle world, and voila!
 * Or maybe she always intended Harry Potter for muggle audiences. At least since The Wonderful Wizard of Oz, witches have been portrayed as forces for good, and not someone you should burn at the stake. So the HP books were made to test the waters: a primer on Wizarding Britain, written for Muggles, disguised as an Urban Fantasy series. Depending on the reaction received, the wizards may have come out of the broom closet, so to speak. However, while the main characters are adored, the general opinion of the Ministry of Magic is that it is filled with incompetent Jerk Asses. Reform needs to happen before they join Muggle Society.

As a Horcrux, Harry couldn't have died at all except to things that can destroy Horcruxes (Basilisk venom, Fiendfyre, etc).
As Hermione says when she talks about Horcruxes, they're virtually indestructible. Any damage to a Horcrux will be repaired; the only way to destroy a Horcrux and render it inoperable is to damage it beyond repair with an incredibly destructive force. That's why Riddle's Diary was perfectly fine after being flushed down a toilet. So Harry, being a Horcrux, should have theoretically been invincible during the time when he had Voldy's soul in him, meaning that the only things that could have killed him were Basilisk venom, fiendfyre, and potentially the Killing Curse (technically, it doesn't destroy things beyond repair, since it doesn't do any physical damage, so it probably shouldn't be capable of destroying a Horcrux).
 * This troper got the sudden image of Harry dying of Avada Kedavra, and his body then becoming possessed by the fragment of Voldemort soul on him.
 * And that subguess has already been guessed above, including of course that it was Harry's body and not Harry himself that was the horcrux.
 * This might explain why (aside from being the main character, therefore unable to die or there'd be much less story to tell) he can survive so many attacks.
 * But wouldn't that mean the Horcrux part of Harry should have died in Chamber of Secrets, after he was bitten by the Basilisk? All evidence points to the destruction being instantaneous, so the Horcrux could've still been destroyed before Fawkes came along and saved Harry, the host.

A Horcrux does not require one murder, but one murder and one rape (no requirement for any connection between the two.
JK Rowling said that "something nauseating" was required beyond just a murder to create a Horcrux. Perhaps Voldemort just did this a lot of times so he could make as many as he wanted, which is why Harry turned into an unplanned one.
 * This troper thought that that other thing was never get any sort of remorse for the murder, as remorse would re-unify the divided soul, preventing the making of a Horcrux
 * I thought that creating a horcrux needed a special dark ritual, murder alone not being enough.
 * It's confirmed that it involves a ritual and a spell, and that Rowling knows exactly what that entails. If and when the HP Encyclopedia is published, it will be documented, and whatever it was, Rowling's editor said he "felt like vomiting" when she related it to him.
 * Maybe cannibalism? The term 'Death Eaters' makes one wonder...
 * Okay, seriously: does someone that regularly contributes to this page have a rape fetish or something? Because this is like the 30th mention of rape on a page of a series where there are exactly zero rapes shown.

There are ways other than murder to split the soul.
Mostly the sort of thing that can cause Angst Comas (when the functional majority of the soul flees the body) or even trauma-induced dissociative identity disorder (when both fragments of soul remain in the body and are each sufficient to have at least recognizably human motor skills and thinking capacity). It's just that nobody happened to realize this because nobody bothered to put a soul catcher on a person before they became the subject of Procedure 110-Montauk (etc.), nor has any wizard with Sight viewed such an occurrence without going mad from the revelation or experience.

The age line in Goblet of Fire was part of a Secret Test of Character.
If a student was under the age minimum and could find a sufficiently sneaky way to enter their name (or even any way, if the teachers weren't to stop someone tipping it in with an eleven-foot pole), they would be allowed to enter. It was only Harry's unconventional and illegal entry that caused the school heads to bring up his age, and they would not have complained (nay, they may have smirked with joy) had the small fourteen-year-old been Hogwarts' only champion. The age line simply acted as a pre-test for younger students, to prevent every immature student who thought the idea of being Champion was cool from dropping in their names. Of course, this follows my original assumption from the first time experiencing the story that the beards on Fred, George, and Katie (along with being expelled from the circle) were a result of Dumbledore adding an "insult-to-injury" clause to the age line's programming that punished anyone who attempted such an un-innovative technique as age alteration.

Ghost are a type of pensive or patronus.
Ghost are silverish in color, like removed memories, and patronuses which are made of happy memories. When a wizard dies unhappy they can leave all their memories behind so that the soul can move on unburdened, or be reincarnated. The coldness a ghost produce is from the feelings of depression left behind the same way dementors suck out all the warmth.

Wizards and Witches are descended from Fae.
This explains where their magic comes from. They appear as full human because the Fae blood has been diluted for centuries. They can have special abilities, such as metamorphmagi and animagi, because a few individuals have inherited more Fae blood as a genetic throwback to their ancestors. This explains why not everyone can become animagi. This also explains the wizarding world's rather skewed morals. The Fair Folk are known to be rather amoral.
 * So muggle-born wizards are changelings?

Only Horcrux's in living Objects work.
Otherwise we'd be up to our ears in dead Egyptians.
 * So, what you're saying is that none of Voldemort's Horcruxes apart from Nagini and Harry actually worked, and that Harry needn't have bothered going on that Horcrux hunt because the other Horcruxes, neither of which were in a living object, were actually useless? Well, that is an idea, but it means we need to find an alternate explanation for Riddle's diary and Slytherin's locket, especially the diary. And for the fact that Voldemort grew more and more monstrous-looking over the years before he'd even made his first working Horcrux (Harry, which was an accident anyway). The canon explanation is that splitting his soul so many times made him more and more monstrous, but if all the Horcruxes up to that point were duds, why does ol' Tommy still end up looking like Mumm-Ra's ugly brother?
 * All in all, I think a better explanation for why we're not up top our ears in dead Egyptians is because Egyptians did not make Horcruxes...

Severus Snape's cloak is a lethifold.
This is why it billows the way it does. And since only a patronus charm can dispel it, it would make good armor.
 * More likely a lethifold's skin, as the guess said before the original author changed the wording, since it doesn't try to eat him. It could be a tame lethifold, though.

Death Eaters
Voldemort came up with the name because he taught his followers some dark magic to steal the energy released from decomposing corpses. So they gain a power boost and the surrounding earth does not get fertilized. Eating Death in a literal sense.

== Wizarding England was in a severe cultural depression during the First Wizarding War. It stayed that way through Harry's time because Voldemort and the Death Eaters did a really good job of shutting the artists up. == Building on what JK said, there's no way that Wizarding England can be a mismanaged cesspool all the time or they wouldn't have had museums, a Snidget Reserve, a clearly-thriving sports industry, and a Wizarding Academy of Dramatic Arts. I expect that in any other time, Fudge would have been considered mediocre but bearable instead of Lawful Stupid and corrupt.

In many historical wars the first thing to be attacked was, in fact, the losing side's art. Literature, music, records, fashion/architecture, sometimes even sacred sites—you name it, the winners will either control it or destroy it. Why? Because among other things, art encourages independence. The Death Eaters would have killed everyone who didn't agree with them or wasn't scared shitless of them, which meant killing the artists who were protesting them (and their families), which meant that the surviving artists had to stop because they wanted to stay safe. The Death Eaters must have done such a good job of beating all the artists into submission that by the time Harry came around, the people who should have been the first to help his cause had become the most cripplingly terrified of Voldemort.

Half of Hogwarts' teachers were spies, which is why there are so few of them in Harry's time.
This ties in with the previous WMG and what everyone else has been implying about Hogwarts' bare-bones curriculum—that they lost half the teachers in the first war. They can't have been solely coincidental deaths (there are way too many conveniently empty classrooms), so it must have been because those teachers were the Order's/Dumbledore's spies. That they were all the artistic ones (drawing/sculpting/painting, music, language, etc.) makes sense because artists are smart, observational, creative, and extremely likely to protest what they know is wrong. The art teacher would have been a huge help with infiltration plans. The music and language teachers would have been the ones who actually went in for the job, and possibly helped with other things. Unfortunately when they lost a lot of teachers to Death Eaters, Dumbledore couldn't find replacements for them because all the other candidates had been killed off, mind-raped, or terrified at the thought of the first two. Hence Hogwarts had to go on a skeleton-crew, which was remedied a few years after Voldemort's final defeat.

The apparently nauseating act one needs to commit along with a murder in order to create a Horcrux is possibly...
Necrophilia, or something close to it.
 * It wouldn't be anything before the killing, or Moaning Myrtle would have remembered it. She's so gossipy I'm sure she would have included every detail when Harry asked her how she died.
 * If necrophilia is part of the ritual for creating a Horcrux, it would have to include oral sex as well as vaginal intercourse, as Voldemort created Horcruxes after murdering male victims. Also, the witch or wizard would have to be able to clean up their mess because Voldemort didn't do anything to the Riddles that had any physical evidence left for the police to find.
 * Maybe biting/eating the body?
 * Nope. Voldemort created his first Horcrux with the murder of his father and paternal grandparents and in the first chapter of Goblet of Fire, it is said that the police were baffled by the fact that all of the Riddles were unharmed except for the fact that they were dead. If he bit or ate part of anyone's body as part of creating a Horcrux, that wouldn't fit with the villagers' account of the Riddles' deaths.
 * The account of Rowling's editor feeling like vomiting when she told him triggered this troper to start imagining increasingly elaborate and disgusting Urban Dictionary-esque rituals involving individual sex acts with names like "Herpo The Foul". Move over Canada's History
 * Perhaps the person creating the Horcrux must murder a person, then replace part of his or her body with the victim's. This has nice parallels with the Horcrux's purpose: requiring one to fragment their body to fragment their soul. Also, it's pretty darn squicky to think of someone going all Nameless One and tearing out their own eye, liver, ulna, or what-have-you and replacing it with that of a corpse's.
 * I always got the impression it was a rather unpleasant ritual (something akin to how Pettigrew brought Voldemort back to life in book 4, only with a lot more blood, or something like that).

Wizardkind doesn't recognize national borders as the muggles do.
There is an offhand reference to either the Transylvanian Quidditch team, or the local Minister of Magic in Goblet of Fire, and in Order of the Phoenix, Neville mentions the plant he got was from Assyria. Transylvania is a region of Romania, and Assyria is the historical name for what is mostly Iraq these days. Wizards are so far removed of the muggle culture that they in areas, disregard these petty wars and national thoughts (but not entirely, as the Quidditch championships proved). That's why Durmstrang is vaguely Ruritanian. Hermione's book about European wizarding schools would suggest there might be more than just the three, but there can't be all that many.
 * Not to mention that Wizarding Britain and Ireland seem to be unified. Seamus, who's Irish, goes to a British school and is never indicated to be foreign; plus, in the fourth book the characters all support the Irish Quidditch team but treat it as a home team, and no Northern Irish Quidditch team is ever mentioned.
 * Couldn't that just mean that there's only one Wizarding school in the British Isles? It seems that England consists of England, Wales and Scotland, but Ireland is independent. They support Ireland, but there's no mention of Wales or Scotland. Or I might be wrong, and Ireland does have a wizard school, but Hogwarts is held in higher regard. Seamus is the only Irish student ever mentioned.
 * If one goes by the film portrayals, Cho Chang and McGonagall are both Scots. The latter probably makes more sense, given the name. As for the Quidditch teams, England's team was mentioned in passing. A lot of times, when there are a wide selection of teams from which to choose in a general area, casual fans will gravitate toward the most successful team. The implication in the mention of England's national team was that they weren't all that good.
 * BTW, also, Word of God states that the school itself is located in Scotland as opposed to "England" proper.

Umbridge was not fired after Kingsley Shacklebolt became Minister
Instead, she was made the sole staff member of the Centaur Liaison Office. It is well known that that office is the absolute worst job in the Ministry, since no centaur has ever shown the slightest desire to liaise with the Ministry of Magic. That, combined with Umbridge's phobia of centaurs, makes it, in this troper's opinion, the perfect job to keep her in, one she couldn't even resign from, so powerful is her need to hold on to whatever power she had left.
 * I love you. That would be Laser-Guided Karma for the evil pink one ...

Just like a wizard can do magic without saying the spell, they can also simply think the wand movements.
In the first book and movie, Flitwick tells them to "swish and flick" for wingardium leviosa. More complicated spells you would assume would require more complicated movements, but you never see anyone ever actually doing them.
 * It could be that they are just never mentioned, and Rowling does mention several times people "flourishing their wands" in heated duels, suggesting that they are flicking wands about in complicated fashions.

Severus Snape is multiracial.
This could be an explanation for his black hair and eyes.
 * JK Rowling said that Alan Rickman was pretty much perfect as Snape, and this comes across in later books. So no.
 * The books say nothing against it.
 * The books also say nothing against Hermione being related to Jennifer Lopez. Does that mean THAT is true?
 * My mental picture of Hermione wouldn't suffer from a little J-Lo family resemblance... (Nothing against Emma Watson, of course)

Severus Snape has magical creature ancestry.
This could be an explanation for his black hair and eyes. I have read Fan Fics where he is/has the blood of a/an elf, vampire, werewolf, incubus, veela (shudder), dementor, and (my favorite) selkie.
 * Would these fics happen to include PossessionSues?
 * Some of them, but there are a few that are actually good.

Severus Snape is a white half-blood Wizard.
Because this theory is just crazy enough for Wild Mass Guessing.
 * This belongs on the Darth Wiki.

Area 51 is the location of the American wizarding school (which still doesn't play Quidditch).
I mean, what would be a better place?
 * And there's also a small annex of the American equivalent of the British Department of Magical Transportation where they test brooms and flying carpets, which aren't banned in America. This is mainly why the airspace is restricted.
 * I am so glad I'm not the only person who has thought of that! I also imagine the American magical government would have to be the Department of Magic, rather than "Ministry", of course.
 * Everyone uses Floo powder to get to school and home, every day. American public schools usually aren't live-in. I also suspect American Wizards blend with muggles better than their English counterparts.

Dumbledore played Seeker for Gryffindor
Eleven-year-old Harry, we are reminded a few times, is the "youngest Seeker in a century". Exactly 100 years prior to Harry's joining the team would be 1891, when Dumbledore was ten. Of course, he wouldn't normally have been eligible to enter Hogwarts at that age, but perhaps an exception was made for the young genius, or maybe "a century" is a casual term for 99 years. Since no mention is made of Dumbledore's Quidditch career in the books, perhaps he simply wasn't very good despite early promise, and quit after a couple years.
 * With what a big deal Quidditch is at Hogwarts, I doubt Harry and everyone else wouldn't be aware of this. I personally always viewed Dumbledore as more of a spectator or someone who picked up the interest later in life, but there's no reason he couldn't have played though.
 * Incorrect. Dumbledore was 150 in the mid-90s. That means he was middle-aged (by Muggle standards) in 1891.
 * According to JKR, Dumbledore was born in 1881, making him 110 years old in 1991, when Harry entered Hogwarts. Therefore, Dumbledore was 10 years old in 1891. That said, I don't think for a second that he was the seeker. Chances are, the "youngest seeker in a century" before Harry was a second-year at best.
 * The youngest seeker would have to be first year cause even Malfoy was able to buy his way onto a team in his second year.

Why was James was so horrible to Snape?
He thought Snape was in an emotionally abusive relationship with Lily. Think about it. A creepy guy who knows an unhealthy amount of the Dark Arts and who is a member of the wizarding equivalent of the skinheads or neo-Nazis (face it, fangirls, he was) is constantly hanging around the wizarding equivalent of insert-oppressed-minority-here. She, who is normally a smart intelligent person capable of seeing people for who they are, constantly makes excuses for him and defends him even when he ruthlessly insults other muggleborns. This might not have been true, as Snape clearly loved Lily enough to switch sides later on, but James doesn't know that. All he sees is a Manipulative Bastard taking advantage and breaking down a woman he sees as smart, intelligent, and whom he is slowly beginning to respect and even love. So when Snape calls her a mudblood, that is it. He's unforgivable. Although Lily might have told him to back off of Snape later when they began dating, he can't. Her asking him to lay off Snape actually cements in his head that Snape was mentally breaking her down and as such hates him even more. Of course Snape wasn't, but all James can see is that bad side of him, just as all Snape (and 90% of the fandom) can see is James's bad side.
 * Since they were eleven years old, though? That's rather dubious. (Unless you mean "emotionally abusive platonic relationship".) But even then, James began sniping at Snape and vice versa on the train to Hogwarts before James had even met Lily. It could be a motivation for the escalation of hostilities between James and Snape, but not for everything.

The Downfall of Voldemort was orchestrated by Rodolphus Lestrange.
It all makes sense. He has a motive (Bellatrix loves Voldemort and not him). He somehow gains knowledge of the prophecy (he could have been around at the time), and decides to lend all of his energy to making sure Voldemort dies. He gets imprisoned in Azkaban, waiting for Voldemort to make his move, and escapes. From there, he slowly assists everyone from behind the scenes, possibly letting Snape in on it (He's not a double agent, he's on his own side). Then, during the battle, he allows himself to be captured. The only thing that goes wrong is that Bellatrix dies, while he only wanted Voldemort dead.

Wands
A list of wands that were not mentioned in canon. Feel free to come up with your own choices.
 * Molly Weasley: Oak with bugbear claw
 * Fig with bugbear claw
 * Arthur Weasley: Apple
 * Bill Weasley: Wild Plum
 * Charlie Weasley: Hickory with dragon heartstring
 * Ash, since Ron's first wand was inherited from him and it was ash.
 * This is his second wand.
 * Crabbe: Redwood with your mom.
 * Percy Weasley: Mountain Laurel
 * Fred Weasley: Cherry wood with jarvey fur or pixie wing core. Reason: Cherry wood is a focus of will, of getting things done, while the jarvey or pixie core is symbolic of Fred's prankish humor.
 * George Weasley: Cherry wood with pixie wing or jarvey fur core. Reason: Cherry wood is a focus of will, of getting things done, while the pixie or jarvey core is symbolic of George's prankish humor.
 * Ginny Weasley: Pine
 * Larch with dragon heartstring
 * Sirius Black: Birch with crup muscle
 * Or rather, hamstring/tendon.
 * Remus Lupin: Fig with mooncalf tendon
 * Aspen with mooncalf tendon
 * Severus Snape: Ebony with unicorn tail hair
 * Horace Slughorn: Beech
 * Minerva McGonagall: Elm with braided kneazle whiskers
 * Pomona Sprout: Eucalypt
 * Filius Flitwick: Walnut
 * Luna Lovegood: Hazel with thestral tail hair
 * Hazel, I think fits. Rowan (from its connection to the moon and power-working capabilities) would be a close second, though, or even primary considering how strongly Rowling pushed the lunar themes. The core, though... Mooncalf tendon (for obvious reasons) or demiguise hair (because... it fits the seeing things that other people don't theme, and...matches her hair... I don't know) might work better.
 * Thestral tail hair because she has an affinity for them.
 * As far as I can tell, she doesn't have an affinity for them so much as that she's one of five or so named people who can see them, and is one of the few students to not assume they're evil just because they look ominous and vaguely skeletal. Point taken, though.
 * Gellert Grindelwald: Rosewood with dragon heartstring. Reasoning: Rosewood (especially true rosewoods) are strong, beautiful, and resilient, and their mystical properties are considered dark and sometimes mysterious. Dragon heartstring just sounds right.
 * Albus Dumbledore: Phoenix feather core. Reasoning: What else. Alder (mostly known for its protection against death, and conveniently being red on the inside which kind of goes with the phoenix and Gryffindor themes) might work for the wood. The Alder tree also tends to have a bit of a metaphorical anchor or solid foundation symbolism to it, mystically.
 * Kingsley Shacklebolt: Teak with Pegasus feather. Reasoning: Teak represents his steadfastness. The Pegasus feather represents his destiny to take down a metaphorical chimera- the Ministry (a lion) in its combined form with a snake (Voldemort).
 * Godric Gryffindor: Oak with griffin feather
 * Helga Hufflepuff: Cedar
 * Rowena Ravenclaw: Rowan with spinx hair
 * Salazar Slytherin: Acacia with basilisk venom
 * Acacia with runespoor skin or ashwinder... stuff. The ash-corpse-thing a first-generation ashwinder leaves when it dies. This is mostly because there are only three magical types of snake mentioned in canon, not counting mystically enhanced or unidentified snakes, and the basilisk is very rare (unlike ashwinders) and has no specific regional territory from which to (carefully!) gather shed skins (unlike runespoors). I think runespoor skin is most likely between them, since the runespoor's heads are planning (ambition and cunning), dreaming (ambition), and criticism (being a Jerkass), and I'm not sure what the minimum solidity is for wand cores (ashwinder corpse may or may not be too powdery).
 * He owns a basilisk remember.
 * Merlin: Hawthorn with incubus hair
 * Hagrid: Oak with acromantula silk
 * I like the wood choices, but wouldn't most of these people have bought their wands from Ollivander? I'm pretty sure it's plainly stated that Ollivander only works with phoenix feathers, unicorn hairs and dragon heartstrings as cores.

Draco had asked Dobby to hex those Bludgers
It was his first game against Harry and he was willing to do anything for the glory of victory. Using his family elf to cheat seemed like a good idea. After he asked Dobby to make the Snitch biased to fly towards him, the elf (secretly seeing a way to accomplish his own objectives) pointed out that this might be too obvious, so they agreed on a trick that would be harder to trace back to them and could seriously injure Harry, a bonus for them both, but for completely different reasons.
 * Come to think of it… the Malfoys could have asked Dobby to do almost everything he did to keep Harry out of Hogwarts, but for completely different reasons than Dobby's. Draco just wanted to make his rival's life miserable, while Lucius didn't want that meddling kid to get in the way of the plan to kill the Muggle-borns and bring back Voldemort.

OK... I think it's stated in book 6 that Lucius had no idea that the diary held a bit of Voldemort. The bringing Voldy-back-to-life wasn't part of the plan... if I recall correctly. His only plan was to to disgrace the Weasley family.

Voldemort's Horcruxes can manipulate the Red String of Fate
In Book 7, the locket Horcrux implies to Ron that it can help him get together with Hermione ("All you desire is possible…"). Because the pair's mutual feelings had already developed by then, such help wasn't necessary. But perhaps Tom Riddle's diary-Horcrux made promises to Ginny regarding a then-uninterested Harry, to help win her trust and allegiance. (Remember, she didn't know the kind of evil she was dealing with, and in her culture Love Potions are considered acceptable.) Four years later, Harry finally got Strangled by the Red String. That's why his affection for Ginny arrives as the infamous chest-monster. Maybe it's even his own Horcrux at work. Lord Voldemort, matchmaker…
 * Text from the penultimate chapter of Book 2: "Little Ginny’s been writing in it for months and months, telling me all her pitiful worries and woes… how she didn’t think famous, good, great Harry Potter would ever like her…" All the time he spoke, Riddle’s eyes never left Harry’s face. There was an almost hungry look in them. Hmm…
 * Yeah, but...that means that Diary!Riddle must have found something attractive about Ginny. A 'spiritual' imprint in the body of a teenage boy leading an eleven- or twelve-year-old girl into a place called the "Chamber of Secrets"? Wrong...on...so...many...levels...

If Snape's life hadn't sucked so much, he'd have been at least as powerful as Voldemort.
As we see from Tonks and Merope, depression drains a witch or wizard's magic. Snape's life sucks far more than Tonks' but he's possibly the third most powerful wizard in the books. Therefore, if he hadn't had an abusive home life, driven away the girl he loved, and been partially responsible for her death, he'd be feted as a prodigy and potentially hailed as the next Dumbledore.
 * An observant and clever WMG if I've ever read one. I'd be interested to see what Rowling would have to say.

Why Harry passes out 12 times every book...
All of his drinks have roofies in 'em. And just his and no one else's.
 * They spiked the squirt. Everyone knows that only Harry likes squirt.

Voldemort had no plan to take over the whole world.
He only cared about England.
 * Voldemort only cared about immortality. But for all we know he had intentions of conquering the rest of the planet once he'd secured Britain.
 * JKR has explicitly said Voldemort's deepest desire is to be "all-powerful and eternal". Literally not dying was only most of his ambition. Control and ongoing influence are vital to him as well.

Slytherin isn't always the "evil" house.
It depends largely on the student body at the time. There are phases where the rash and jock-ish Gryffindors are the most antagonistic, same with the Ravenclaws, who would mock the other houses for being stupid. Hufflepuff probably does this the least.
 * Except Hufflepuff would be the most likely to gang up on an individual. Remember, 'Puffs stick together.

Students use a magical telescope during the Astronomy section of the O.W.L. exams.
The book has Harry looking for Orion in June at midnight (It's behind the sun in June, so you can't see it even if you wanted to), and also looking for Venus (which being the next planet near the sun is always close to the sun in the sky and therefore never visible at midnight). The students use a magical telescope which when pointed at the ground can see through anything blocking to the stars (the sun excluded) that would be there.
 * Well, Harry did get 'Acceptable' on the OWL, so he might of gotten those ones wrong...

Wizards are brain damaged.
It isn't clear how much wine the students drink, but they do give the 11-year old students wine. Their thought processes are impaired because they suffered brain damage from getting drunk on a regular basis as children.
 * What the --? When did this happen?!
 * Except that Europe isn't as crazy about the whole "Underage children must never drink or be near any alcoholic substance ever!!!" thing. I don't remember anything about them drinking, but even supposing that they did, that's probably more of a cultural thing.
 * The Potterverse seems to mostly use pewter cauldrons; perhaps people who grow up in the wizarding world are exposed to significant amounts of lead or other neurotoxic chemicals at especially sensitive ages.

The real reason Hermione was given the time turner.
Hermione says that Professor McGonagall wrote to the ministry requesting a time turner for her so that she can take more classes. But is that really a good enough reason to give a 14-year-old girl (an exceptionally bright and responsible one, but still) a time machine? The real reason she was given it was for the one scene in which we see it being used: the one at the end of the book where Harry and Hermione use it to save themselves and Sirius. McGonagall kept the time-turner after Hermione turned it back in, and some time after the events of the fourth book (likely after the events of the seventh) she traveled back to summer of 1993 and told herself (and likely Dumbledore) that in order for Harry Potter to survive the end of the year, he has to have access to a time turner. She doesn't tell her past self anything else because no one really knows what happens if you alter the timeline, and for all they know it could be more dangerous than Voldemort. They obtain a time turner from the Department of Mysteries and give it to Hermione, who of the trio has the most believable excuse for being given one.
 * And is, of course, far more level-headed and responsible than either of her friends.

The 1993 Daily Prophet Grand Prize Galleon Draw was rigged as part of a Batman Gambit
Although it seems minor, it was actually the inciting incident for the series' central Story Arc of Voldemort's return (and thus his eventual downfall). In Azkaban, Sirius read an issue of the Prophet featuring a photo of the prize-winning Weasley family, including Scabbers/Wormtail with his iconic missing toe. Realizing that The Rat was living in proximity to Harry, Sirius was inspired to escape. This in turn inspired Womtail to "escape" and seek Voldemort.

The mastermind behind this could have been any one of the characters who, however briefly, benefited from the ensuing events: a villain or a good guy. However, a Death Eater perpetrator seems likelier because s/he would have to know that Peter Pettigrew was both a rat Animagus and the traitor, and among the good guys, only Sirius himself did (so far as we know). Alternatively, perhaps the Galleon Draw is determined by a semi-sentient object like the Goblet of Fire or the Sorting Hat, and it chose to initiate this particular chain of events for its own inscrutable reasons.
 * Better yet, it was rigged for the simple reason that everyone wanted the Weasley to win after what happened to Ginny the previous year. This makes Lucius giving Riddle's diary to Ginny the inciting event for the whole series.

The first book was a Batman Gambit by Dumbledore, and Harry ruined it
It seems to convenient that all the "defenses" to the stone were simple to by pass except for the last one, and that Dumbledore mysteriously had to go to the ministry, and then came right back, on the day that Quirrell went to steal the stone. Dumbledore faked an absence from the school to lull Quirrell into a false sense of security, and waited for Quirrell to take the bait. However, Harry also took the bait, and Dumbledore had to focus more on saving Harry rather than capturing Voldemort.
 * I actually had a similar idea (currently trying to work it into a fanfic): The entire thing was a trap for Voldemort, which shows why the obstacles were easy enough that three first-years could get past them. The obstacles had to appear to be difficult, so as not to arouse Voldemort's attention, but possible to get past without too much trouble.


 * However, my theory goes a little further: The Stone hidden in the Mirror of Esired was a fake. In reality, when Hagrid got the real Philosopher's Stone to Dumbledore at the beginning of the year, Dumbledore and Flamel had already agreed to destroy it. Dumbledore knew that Voldemort had infiltrated Hogwarts (whether he knew about the situation with Quirrell or not is uncertain; he did know that something was up but may or may not have had all the details). And so, Dumbledore and Flamel make a decoy stone while destroying the real one—Flamel and his wife have enough elixir left to keep up appearances for a year or so, and so only those three people know that the Stone has been destroyed.


 * Over the course of the year, Dumbledore subtly let's Voldemort find out how to get past the obstacles, and then pretends to be called away from Hogwarts on urgent business. However, he had not counted on Harry getting to the same conclusions... and so the entire thing takes a slightly different turn than he'd planned, but the end result is that Voldemort is effectively purged from Hogwarts.


 * And so when Harry is in the hospital wing and the first thing he does when waking up is ask whether the Philosopher's Stone is safe, Dumbledore (impressed with Harry's bravery and knowing that the boy will have to face Voldemort again sometime in the future) just doesn't have the heart to tell him that the entire ordeal was completely unnecessary and that the Stone Harry saves was a worthless decoy. So he lies just a teensy bit, pretending that he and Flamel have just now decided that the Stone should be destroyed—when in reality, it had already been destroyed several months ago.

Lily contributed to the tips written by Snape in the Half-Blood Prince's Advanced Potion-Making textbook.
Lily and Snape were close friends until the end of their fifth year and may have been in the same Potions class. Slughorn frequently praises Lily as one of the best Potions students he ever had. It's possible that Lily and Snape worked together to discover the various tips and techniques found in the textbook. Hermione even remarks that she thinks the handwriting looks like a girl's.


 * No, This has already been disproven. Furthermore Just because the writing looks female does not mean it was written by a girl. There are men out there who have feminine handwriting.

The Ministry of Magic is a dictatorship
There are no elections - new ministers are picked from the Ministry elite. The mainstream media (The Daily Prophet and the Wizarding Wireless Network) pretty much say whatever the Ministry says. People are arrested and held without trial (see Stan Shunpike).
 * Good theory. However, in ''Deathly Hallows"", during the Potterwatch scene; Lee tells Kingsley he has his vote for Minister.

Being chosen as a Triwizard champion by the Goblet of Fire forms an Unbreakable Vow
Dumbledore mentions that the Triwizard Tournament was discontinued when the death toll became too high to ignore, which could be from younger students dying (through breaking the Unbreakable Vow) when they try to chicken out if they only signed up for the Tournament because of Eternal Glory!!1! and found themselves way over their heads. The age limit was imposed not only because of the advanced level of magic, but to prevent younger, egotistical students from being locked into such a dangerous tournament, attempting to back out, and die.
 * That would surely be illegal, unless the information had been lost after the Tournament being discontinued for so long.

Fiendfyre was introduced prior to Deathly Hallows.... just not in the books.
It was, however, introduced in the films. Half-Blood Prince specifically. Whenever the Death Eaters, this is what Bellatrix (nonverbally) casts. Think about it. The screenwriters did say that Deathly Hallows influenced how they wrote the script for the sixth film; maybe this was their own way of somewhat rectifying the rather Deus Ex Machina nature of it in the books, as well as keeping with Rowling's grand tradition of Chekhov's Guns. As a matter of fact, Fiendfyre may have even been introduced in the Order of the Phoenix film (not sure about the book; I haven't reached it yet): Wikipedia says Fiendfyre is a "Dangerous, uncontrollable and extremely powerful fire which can take the form of beasts such as serpents, Chimaeras and dragons". In Voldemort's battle with Dumbledore at the Ministry of Magic, he nonverbally summons an enormous flame which then takes the form of a snake. Granted, it says Fiendfyre is uncontrollable and Voldemort was controlling it (somewhat), but still. I mean, he is one of the most powerful wizards of all time. Who's to say he couldn't control a Fiendfyre spell?

Also, I wasn't quite sure where to put this WMG as the WMG page for the films says "WMG about the actors in the movies, the directors, the screenwriters, all go here", and this doesn't really relate to those save for just barely the screenwriters. If anybody thinks this should be removed and put in the film's WMG, I will gladly do so.

The snake that was released in the zoo was Nagini
Not sure how to totally work it out.... but it seems.... plausible?
 * But Nagini is venomous, and the snake at the zoo was a boa constrictor.
 * Ahhh, but, in both the book and the movie, Nagini is large enough to consume a human, which no nonmagical poisonous snake is capable of, but anacondas are. So ... snake escaped, Voldie got his hands on it, magicked it up and slapped a horcrux in it. Or maybe putting the horcrux in it lent it poison and the relevant fangs?
 * Jossed long ago, but most explicitly so in the second Fantastic Beasts film.

Gilderoy Lockhart is a sociopath
He has no empathy for anyone but himself and yet convinces everyone else he's absolutely charming. Plus he's very ambitious.


 * I think what you mean is Psychopath. Sociopaths are the result of a terrible environment. Furthermore they are not charming what so ever. Psychopaths are charming and manipulative. Since Lockhart was charming and able to fool many many people into believing and loving him I would put him as a psychopath or just a narcissist.

House elves used to be the dominant species in the wizarding world
They have been enslaved by human wizards for centuries, but when freed appear to be almost as powerful naturally as an expertly trained wizard. All civilizations must start somewhere, so at one point humans must not have had very strong magical powers, while elves did - one's magic requiring spells and learning, the other's nothing at all. Elves probably acted like The Fair Folk, and were the supernatural entities of most myths which predate written language. However, as writing started to become more well-spread, functional magic could be passed on between generations more efficiently. Human wizards started to become more powerful, and overthrew the house elves and bound them in servitude, since they were too useful to kill, but too threatening to keep at full strength. Since the elves no longer caused people to believe the old myths, gods changed from beings which were not impossible to be found bathing in your local pond into gods as we know them today - acting more like a magical council of elders (which might well be the magical organization at the time).
 * SPEW could be opening a bigger can of worms than they realise.

Muggles don't have souls.
Wizards assume that muggles don't make ghosts because their lack of magic prevents their souls from staying in this world, but it could be that they just don't have souls. I'm surprised Death Eaters never made that point.
 * The dementor wouldn't have tried to "kiss" Dudley if muggles didn't have souls.

Snape hated Neville because the Longbottoms weren't targeted instead of the Potters.
I always did wonder why he picks on Neville so much. While it's true that he's awful at Potions there seemed to be a certain vindictiveness that was normally only reserved for Harry and friends, which he directed towards Neville even before he actually became friends with Harry (Generally bullying him and doing things like the time he threatened to test Neville's antidote on Trevor as incentive to force him to get the potion right in fourth year). He's excessively cruel to Neville for no real reason other possibly being a Gryffindor and I always thought it was weird even for Snape, until this occurred to me.

Think about it. Voldemort had a choice between two families the prophecy could have applied to, the Potters and the Longbottoms. In the end he chose the Potters, but if he'd chosen the Longbottoms, Lilly would still be alive. It might be unfair to Neville, but with the way Snape projects his hatred of James onto Harry, it would make perfect sense to Snape.

Santa Claus is a wizard.
So tell me, what magical creature exists in the Harry Potter universe that has to serve their master no matter what? House Elves. What does floo powder do in order to teleport you? Puts you in the fireplace. The Reindeer? Their sleigh bells are enchanted, enabling Santa to fly at super speeds just like Mr. Weasley's car. He used to use reindeer before he was aware of the existence of floo powder and had a smaller rout than he does now.
 * And he has a time turner, allowing him to visit several houses at once. That's how he manages to visit the world's entire population of kids (except those who don't celebrate Christmas or believe in Santa) in one night.

Those times where they make note of a wizard being a Fish Out of Water are the exception, not the rule, and they get reprimanded for it later.
Because if all wizards were so ignorant of Muggle culture, they would be living in an Unmasqued World by now. There are very few places you could live that are all wizard (school grounds, Hogsmeade, maybe a few apartments above the shops in Diagon Alley), so using Muggle infrastructure without drawing attention to yourself is really a basic skill that they need to keep up the Masquerade. At least one point a wizard mentioning that he didn't know muggle men wore trousers, which implies he has never been on streets inhabited by muggles which, by the way, are most of them.

House elves are descended from forest elves, or something of that nature.
This is mostly based upon their name; calling them House Elves instead of just Elves implies that there are or were elves which were not House Elves.

Lily's parents were stage magicians.
Petunia said that her parents were ecstatic over having a witch in the family. This might be because they themselves were "magicians" but of the Houdini variety and loved that Lily's magic was "real."
 * Stealing for fanfiction. 3

James Potter and Sirius Black were mild sociopaths.
I'm a little flaky on how sociopathy works - can you have a "mild" sociopath? But if you can. . . James and Sirius showed definite sociopathic tendencies in Snape's worst memory. It certainly wasn't what I would call a casual incident, but the Marauders went about it casually and it was certainly implied that this horrific bullying was pretty normal for them. James and Sirius did it because they were bored and showed no remorse later (sociopaths don't have much of a conscience,) and after Lily told James what she thought of him and stormed off, instead of letting it go and leaving, which is what most bullies I know would do, James actually ups the ante. The only problem with this theory is that James goes on to have a pretty normal relationship with Lily, which sociopaths can't do. . . But Sirius doesn't have many close relationships, and his relationship with Harry was subject to mood swings, and he showed bad judgment. . . hmm.
 * Then again, what Harry saw of his fathers childhood was through Snape's memories. It's possible they might have been caricatures of their actual personalities, warped through Snape's eyes (I'm not saying that they never bullied him, or had at least some of the personality traits Snape remembers them having - merely that his mind turned it Up to Eleven).
 * Jossed because JKR says that Pensieve memories are completely third-person, so the memories were not warped in the slightest - they weren't affected by Snape's mind at all.
 * Possibly this applies to Sirius, who not only declined to show remorse (and remember, he actually willingly sent Snape into the habitat of a werewolf!) but also still acted like a bully towards Snape. Can't be sure about James though, considering we don't really know how he acted as an adult, and also remember he didn't agree on the whole "kill the unhygienic emo kid" thing to be a very funny joke. A cruel kid, sure, but I'm pretty sure we all know people who were jerks in school and grew up to be completely normal people.
 * Not really, but I'm sure they exist. From personal experience I mostly know of people who were cruel as teens and grew up to be criminals. I keep an open mind though . . . As for Sirius, yeah; I don't think he even had a particularly healthy relationship with anyone - not even Harry; he seems able to show affection but he's extremely irresponsible and careless as an authority figure, and I don't view his relationship with Harry as particularly healthy from his side anyway.
 * So, is "such-and-such is a sociopath" the new "such-and-such has Asperger's"? Because it certainly seems like it.
 * Haha, I don't know - is the Asperger's thing some kind of meme? I hadn't heard of it . . . But in my case I don't actually think that James, at least, was an actual sociopath. Sirius *is* a bit dodgy though . ..
 * Jossed

The Marauder's Map was a horcrux

 * A piece of writing that retains the memories and character of its creators, and is able to communicate with the reader. Remind you of anything?

Barty Crouch Jr. was under the Imperius Curse when he tortured the Longbottoms.

 * He says at the end of the book he hates nothing more than a Death Eater who walked free, so why was he trying to get off of a crime at his trial? He didn't know what he was doing. Kid grew up being the "Well Done, Son" Guy, and getting no love from his father. His mother who loved him died, and he was left into a family with a man who hated his very existence, even more since he tarnished his reputation forever, and a house elf who did what she could. Its possible that the Imperius Curse, if used for too long, might give its victim severe brain damage or cause insanity, he's the only character we know was under one for many, many years. He may have joined willingly to spite his father, or out of the lack of love he received from his father, whom he quite possibly admired, and was fairly loyal, but did not torture the Longbottoms of his own free will, since Voldemort calls him his most loyal servant. Or he was Imperiused by another Death Eater, and not Voldemort. His insanity from being under the Imperius for so long drove him to become a loyal member of the Death Eaters by the time Voldemort came calling. Due to his father being the one who imprisoned him, he grew to hate him, and hate him for putting him in prison, so he grew closer and closer to the Dark side, because in his eyes, the good side was made up of jerkasses like his father and the court who put him in prison, and Voldemort and his Death Eaters were far more accepting than his own father was.

Wizards are Immune to Bullets.

 * Obviously a gun could beat a wand in direct combat, as guns fire much faster than spells, so there is the obvious question of why wizards don't use them. I think that for some reason, bullets do not work in the wizarding world or against wizards.
 * Jossed. J.K. said that if it came down to a wizard and a muggle with a gun, you'd have a dead wizard.

Neville witnessed his parents being tortured.

 * At least, this troper was under the impression that Frank and Alice were at their home when Crouch and Co. showed up. The reason Neville himself was not tortured was either because there was no point in torturing a young child, or Wouldn't Hurt a Child (back then, anyway, though Death Eaters are known for wiping out families with young children), or Neville was well-hidden. Something about his reaction to the spiders being tortured by Crouch!Moody (book and movie) just makes me wonder... that would be quite traumatizing to a 5 year old (how old Neville was when his parents were tortured, or maybe I need to read Goblet of Fire again...) and would explain why he never, ever actually says this (the scene in OotP does not count as mentioning it, as Harry and Co. run into him) until the sixth or seventh book when Harry already knows.
 * I get the impression the attack on the Longbottoms happened just a few weeks or so after Voldemort's fall, which would make Neville a baby, but I can't think of anywhere this is stated affirmatively in the books.

Suffering the Dementor's Kiss while having a Horcrux is a fate WORSE than a fate worse than death
This idea spooked me. We all know that you can't die when you have a horcrux right? And when somebody is 'kissed' by a dementor they lose their soul. So what would happen if you had a horcrux because part of your soul would be away from your body.

This becomes Fridge Horror when you realise that not only would you become a living vegetable but ... you would never die of old age or get killed and thus be able to move on. You'd be trapped in a state of nothingness for ETERNITY. The only way out would be if somebody destroyed your horcrux ... but if you didn't tell them during your life then you would never be able to tell them after being kissed. And even if they knew, how many people have the skill to cast fiendfyre or have a basilisk fang present? Brrrr...
 * . . . AHHHHHHHHHHHHHH!!!!

Ginny's cessation of her Quidditch career has nothing to do with Career Versus Family.
Word of God confirms that Ginny played Quidditch for the Holyhead Harpies from her graduation from Hogwarts (probably captained the team in 1998-1999 and was picked up right out of school like Oliver Wood was) until she found out that she was pregnant with James Sirius. At the same time, Harry Potter is an Auror, probably in command of his own squad and tasked with the job of mopping up remnant pockets and/or splinter groups of the Death Eaters - something which happens often after a war and can often be as dangerous as the war itself. Either way, as an Auror, Harry likely spent long periods of time away from home, which would presumably be true as well for Ginny if she was playing in Quidditch matches all over England. So when she found out she was pregnant with James Sirius, she had to take a year or two off from Quidditch anyway and probably realized that both she and Harry couldn't be away from home for long periods of time if J.S. was to grow up in a stable home environment. So she did what many retired athletes do and became the magical equivalent of a sportswriter.

Armando Dippet's lack of awareness of the times in the Muggle World led to problems for the wizarding world later.
Dippet may have been, like many wizards, something of an isolationist. Brought up in the wizard world and dealing with wizard world issues, the problem of a muggle World War being right on Britain's doorstep might not have occurred to him. Harry Potter proved that one could spend his early childhood in an environment that was not very nurturing and recover from it if good family figures (in his cases, people like Sirius and the Weasleys) were put around him. There may have been several teenagers brought up in similar environments - wizards raised by muggles that may or may not have been killed during World War Two. Naturally, most of these children would end up in British muggle orphanages, exposing them further to the horrors of the war, but also cutting them off from nurturing contact from other, older wizards. And it's possible that it was this group of children that became the original Death Eaters. Word of God says that Voldemort was brought into the world in a one-sided act of passion (his father was under the effects of a Love Potion, which, despite its name, only causes strong infatuation - as mentioned by Slughorn in HBP) and raised in an environment where people felt obligated to take care of him...and that he would have turned differently if brought up in a loving environment. It seems strange that there were no families that would want to take in a seemingly bright, talented, and upstanding young man like Tom Riddle - or that there was nowhere in wizarding Britain where orphaned young wizards could live during the summer holidays. Dippet's and the Ministry's failure to make provision for these children, especially during WW 2, might have had a hand in creating the monster that was Voldemort (and by extension, the Death Eaters.)

Harry eventually becomes Hogwarts' Defense Against the Dark Arts Teacher.
I know that he became an Auror and head of the Auror Department, but afterwards, when there is less of a threat from Dark Wizards, you'd think he'd consider this option. Because of Voldemort's jinx on the job for a few decades, there must still be a shortage of suitable DADA teachers, and, provided the jinx was lifted after Voldemort's demise, he'd be an obvious option. He's very skilled at fighting the Dark Arts as was shown in the books, and he's had experience with teaching defensive spells to students back in Year Five with Dumbledore's Army. You don't get much better than having Harry Freaking Potter as a DADA teacher. Also, Hogwarts is his home, he's said so himself; he'd miss it eventually, and might consider going back there as a teacher once his Auror days are over.

'Ambition' is a nice of saying 'wizard supremacist'
Ambition can make people evil, but it shouldn't turn them into a mudblood-hating Nazi-wizard. We know that Salazar Slytherin disliked muggle-borns and had the ideal of Voldemort long before Voldemort was even born. Now, the teachers didn't want to come out and say this is the house for future wizard-Nazis, so they came up with the most politically correct term for people who want to wipe out all the mudbloods, enslave the muggles and glorify the purebloods - ambitious.
 * Alternatively, Slytherin's original qualities (ambition, drive, natural leadership) were flanderized into this, either by the passage of time, or maybe even by J.K. herself.

All the best wand-makers are some form of immortal.
Gregorovitch really is Father Christmas (which sadly implies that Santa is dead, or at least the European version is), and Ollivander has been operating his own shop since 390-whatever BC. In fact, Ollivander in the first movie looks oddly like the Second or (sometimes) Eighth Doctor... The reason it seemed like just yesterday that Lily (and James?) got her (their?)wand(s) could have been that for him, it literally was yesterday, because he works long hours and skips all of the time that a customer is not being seen (and that he is not being asked to do something else, like officiate for the Triwizard Tournament).
 * So wandmakers are Time Lords? I can agree to this.

Hedwig is a Hufflepuff.
Her defining attribute is loyalty (to the point that, at least in the movies, she'd - i.e., loyalty over obedience). Additionally, she's a particularly good finder; she can find Sirius even when he's in hiding and she doesn't know where to start looking.

The reason Luna has Attention Deficit Ooh Shiny tendencies is because she actually has ADHD.
In the Muggle world, she'd probably be diagnosed. This explains why she's so easily distracted when she's meant to be doing other things (like commentate a Quidditch match).
 * I myself assumed this to be the case. She definitely seems like someone with diagnosable attention difficulties. She's also absent-minded enough that people steal her stuff and hide it from her.
 * I always assumed she had Asperger's and ADD. Then again, it might be because I have those disorders, and I'm quite Luna-like.

The process of creating a Horcrux requires unicorn blood.
Each will save your life, but results in a Fate Worse Than Death. Horcruxes are a more extreme version, due to the other elements involved in Horcrux creation.

Bellatrix is responsible for Moody losing his eye.
Moody still had two normal eyes at Karkaroff's trial, which takes place after the end of the war. So how did he lose the eye? Well, when the Lestranges and Crouch Jr. were being captured by the Aurors, Bellatrix threw her knife at Moody out of spite and it hit him in the eye. You'll notice that Moody isn't mentioned being present when Harry sees the trial of the Lestranges and Crouch Jr. That's because Moody was in St. Mungo's at the time.

The Cruciatus Curse was originally designed as a tool for righteous retribution.
The curse was designed to be cast by only people who felt that they were really, truly justified in casting a torture spell, because it would be giving back what their tormentor cast upon them, or them by proxy of their family and/or friends. However, since magic isn't a perfect test system that can be written and rewritten before the final product is released, dark wizards noticed that the spell is actually looking for whether or not you really, really want it to work (presumably, nobody good would really want to torture someone unless it was in the name of truly righteous "justice" [or at the very least, retribution]). This is shown in the name of the curse: It (translating roughly to "the tormented" or "tormented one") refers to the people who were originally meant to use it, not the people at whom it would be aimed.

A part of the ritual for creating a Horcrux is a spell that endows the Horcrux with TYPE II Immortality
That is, a living creature that is a Horcrux will be immortal, but it will not die unless it's harmed beyond repair. If a living Horcrux could die of natural causes, why would Voldemort have chosen a living creature to be one of his Horcruxes? This scenario would be one where the living Horcrux is Cursed with Awesome: you're essentially immortal unless you're physically harmed beyond repair, but you're the receptacle for a mangled part of some evil, fucked up person's soul.

Slytherin House was much 'worse' than usual during Harry Potter's school days for a very simple reason.
A large portion of Slytherin House were probably not just children/grandchildren of Slytherins, but (grand)children of the first generation of Death Eaters, who obviously had all of the pureblood supremacy, except cranked Up to Eleven. This is obviously confirmed with Malfoy, Crabbe, and Goyle, so it would probably follow with many of the Slytherin children, to an even greater degree than other generations.

The Sorting used to be a magical selection system, but centuries of tradition have turned it into self-fulfilling prophecy.
Simply put, since the Sorting Hat associates, say, Gryffindor, with courage and chivalry, the desire every child has to fit in with his/her peers will eventually bring out those qualities.

Blaise Zabini's mother's character is a Stealth Pun.
Despite previous fandom portrayals to the contrary, Blaise Zabini is black - almost certainly through both parents. His mother was/is famous because she was a witch who had married several rich husbands, each of whom died not long afterward and left her and Blaise a rather large sum of money. The implications here are pretty obvious. In any case, Mama Zabini is a Black widow - paralleling the namesake spider, whose females kill (eat?) a male shortly after mating with him.
 * Okay, how the hell did no one notice this before?
 * I'm pretty sure he's only black in the movies, and the books say nothing about his race. Which means, if it's a pun, it wasn't Rowling but Casting Agency who came up with it.

Cho Chang's parents are from Hong Kong and emigrated to the British Isles (possibly Scotland) at some point during Cho's early childhood.
It would certainly be a very good explanation for a girl of obvious Asian descent to be attending a wizarding school in Britain. Also, one of the probable linguistic origins for Chang's name is Cantonese, which is the official dialect of Chinese spoken in Hong Kong. And, since the series takes place in the 1990s, Hong Kong would have still been under British control. As for why they moved, it's not hard to imagine that there wouldn't be a particularly large wizarding network in Hong Kong - or at least not a Wizarding School that had English as a first language. So, when they realized that Cho was a witch, they may have wanted to be able to bring her up around other wizards and witches. One or both of her parents probably would have found jobs, then, on the strength of a chance encounter with Dolores Umbridge, which would explain why they would be reluctant to get on her bad side. In the books, it's probable that Cho grew up in or near Tutshill, given her support of the local Quidditch Team (which would seem very random were she not from there). In the films, on the other hand, she has a very obvious Scottish accent. Make of that what you will.
 * Rowling is actually from Tutshill. I don't really see how this would be a "wild" mass guess, though, most Asians in Northern Europe are immigrants.
 * There are lots of Chinese living in Britain, many come from Hong Kong region. This is more like a regular guess than a wild guess except for your insistence that Cho was born in China and her family moved to Scotland when she was age 3. I see no problem with Cho being born in Scotland because her family moved here before she was born,

Percy Weasley "chose" his house, just like Harry did. Or, alternatively, the Sorting Hat chose one for him for his own long-term benefit.

 * Percy would have obviously come into Hogwarts on the very tail end of Bill and/or Charlie's time there. And, obviously, given the fact that both of his parents and older brothers (whom Percy probably looked up to as a young boy) were in Gryffindor, he probably felt a bit of direct or indirect pressure to become a Gryffindor as well. However, most of the second half of the series displays that he probably should have been put in another house. More than likely, Percy Weasley should have been in Slytherin. He was very ambitious and, on top of that, the Weasleys are a pure-blood family (it says nowhere that being a pureblood supremacist is a trait associated with Slytherin - simply being pure-blooded in and of itself. The Weasleys may not have acted like most pure-blood families, but they were pure-blood.) And the Sorting Hat probably reasoned that Percy would have been a good fit for Slytherin. From there, one of two things happened.
 * 1: 11-year-old Percy started muttering, "Not Slytherin, anything but Slytherin" or something to that effect, and the hat decided to put him in with his family in Gryffindor.
 * 2: The hat recognized that the Slytherin influence might cause his ambition to grow out of control and separate him even further from his essentially good-hearted parents and siblings, and thus put him in Gryffindor anyway, knowing he could "climb the ladder" as a Gryffindor without being tainted by Slytherin's potential negative influence.

Mrs. Norris is more than Filch's magical familiar.

 * Filch likely had Mrs. Norris since he became caretaker of the school, if not longer. If Filch had been there for a while before Harry's first year, that would have made Mrs. Norris a very old cat. On top of that, Mrs. Norris had to have been living at Hogwarts for an extremely long time to memorize nearly every passageway in the castle. Not to mention the fact that she seems to know where Filch is at all times is a bit strange. Also, while some people can certainly be ridiculous about their pets, Filch and Mrs. Norris always seemed a bit too close. Like the scene in the fourth movie where's he's dancing with her at the Christmas party? Creepy. Not to mention his over-the-top reaction to seeing Mrs. Norris petrified in CoS. In the book, he yells that he wants to see some "punishment." And, given the methods of punishment Filch would have really liked to use if he could have gotten away with it, he might as well have said "I want to see some torture!" In the movie, he was a bit less ambiguous. As mentioned before, some people can get really ridiculous about their pets, but Filch seemed especially emotional. The answer? Mrs. Norris is really a witch - or, more specifically, an unregistered Animagus. She and Filch fell in love at some point during their younger days, but since he was a Squib, her parents didn't approve and she ended up marrying Mr. Norris instead. Then, if she wasn't already an Animagus beforehand, she became one, faked her own kidnapping and/or death to get away from her husband, and ran off with Filch to become his 'assistant.' But she has to stay in her cat form so no one ever figures out her identity. (Or alternatively, she somehow botched the transformation process and can't turn back, and Filch can't/won't tell anyone for fear of her being exposed.)

Some species of animals (not counting Magical Creatures such as hippogriffs and the like) have their own 'wizarding' gene.

 * Only a select several species of animals are allowed at Hogwarts. Yes, this is partially for practicality purposes (the mess would be unbelievable if, say, dogs were allowed), but it seems strange that, out of so many small animals that could be practical to keep as pets in Hogwarts, only a handful are actually allowed, and all of them (except perhaps the toad) are animals that would not be or are not allowed to be kept as pets in the Muggle World. This suggests that the three selected animals, as well as the domesticated housecat (which seems to be a favored animal by witches) may have deeper connections to magic, despite not falling into the category of 'magical creatures.'

One of the members of the D.A. became the Defense Against The Dark Arts teacher by the Epilogue.

 * This would have been more likely to be a member who, unlike the Trio and others, may have been too severely injured at the end of the battle to take part in full-time Auror work, and settled down to teach instead.
 * This theory is supported by Word of God stating that Harry was brought in as a guest lecturer fairly often, indicating that the full-time prof was somebody that knew Harry knew his stuff.

Professor McGonagall and Augusta Longbottom were fellow Gryffindors, perhaps old friends and/or roommates in the same year

 * McGonagall certainly had a good memory when it came to the fact that Augusta failed her Charms O.W.L. So, unless McGonagall tested Augusta (which seems unlikely, given that they were about the same age), she probably found out when the two compared test results as students. Also, McGonagall had to be fairly confident in her relationship with Augusta to write her a letter essentially telling off Augusta for not appreciating Neville as he was. Not to mention that she was a bit more warm with Neville - not so much as she was with the Trio, but also a bit more than other students.
 * Additionally, her harsh punishment on Neville for dropping the long list of passwords (which, despite his bad memory, he likely wouldn't have needed if Sir Cadogan wasn't being an ass) was a Batman Gambit. She hadn't heard from Augusta in a while and wanted to talk to her, and knew Augusta would probably send a letter to the school after Neville told her what had happened.

Scorpius Malfoy, much to the shock of the Potter/Weasley children, is sorted into Gryffindor.

 * Why not? Word of God says that Draco raised Scorpius to be a better person than he had been in his younger years. And presumably, part of that involved telling Scorpius about some of, if not all of, the mistakes he (Draco) had made during his school years. He probably got a bit of this (although probably not as much) from his grandparents as well. In the end, he might have wound up with the same bad taste in his mouth about Slytherin that a lot of the main characters had in their first year at Hogwarts.

Albus Severus does not get his wish. He is put in Slytherin by the Sorting Hat, who has no choice...

 * ...because, in the years since the war, Slytherin House has been teetering on the brink of nonexistence. The war brought its reputation down to an all-time low and people began to wonder if the house itself was cursed. Long story short, the hat has to put some kids in Slytherin because hardly anyone wants to go willingly.
 * Why do people insist that Slytherin is a bad House? There are people who fit there naturally. It wouldn't become non-existent because nobody wants to go there because of it's reputation, it would continue to have the same amount of kids, because there are people who have Slytherin qualities. Slytherin isn't evil, and there actually are people who would still want to go there. Your theory makes absolutely no sense. There are people who belong there, it wouldn't become extinct just because there are no more Death Eaters. The hat is very forceful, and if it thinks you belong there, well, tough luck. Neville was begging to be a Hufflepuff, but was Gryffindor because that's the House he fits. In fact your theory actually contradicts itself. If the hat will force Albus, it can force other people. Ergo, Slytherin would never be "teetering on the brink of nonexistence". The hat won't just stick people where they don't belong. Harry could have gone anywhere, and the hat debated on Slytherin because Harry does have it's ambition, and, more importantly, part of Voldemort's SLYTHERIN soul in him. Harry as a person never shows much in the way of Slytherin qualities. It put him in Gryffindor because it knows Harry is a true Gryffindor. The Hat doesn't put people wherever just because the House is lacking. Albus would go wherever he belonged, just like everyone else.
 * OP here. That's exactly my point. Slytherin =/= evil, but in-universe, it wouldn't be so far-fetched for it to have a reputation as such after so many Death Eaters went through it. This was certainly the case in the first book, with sweeping generalizations such as "There isn't a witch or wizard who went bad who wasn't in Slytherin" - which was, of course, disproven by the appearance of Peter Pettigrew (who was sorted into Gryffindor.) Of course Slytherin House wasn't evil by default, but its reputation in the Wizarding World would have to take a hit considering that most of the top Death Eaters and Voldemort himself came from Slytherin House. And in the Wizarding World, many more of people's superstitions (like the suggestion that someone had cursed the D.A.D.A. Professor position at Hogwarts) turn out to be true. And as for suddenly forcing students to enter certain houses, there are some hints toward the hat being somewhat sentient...
 * Alternatively, Albus is automatically sorted into Slytherin for having the ambition to make a name for himself that doesn't automatically make everyone think 'Harry Potter'.
 * Just Harry Potter? That might be understating things a bit. Try Harry Potter, Severus Snape (who was probably Vindicated by History), AND Albus freaking Dumbledore.
 * He wasn't. Word of God says that even though Harry tried to clear Snape's name, everyone remembers him as the asshole who killed Dumbledore.

Hogwarts is a House Elf sanctuary.

 * When Hogwarts was founded, one of the Founders, most likely Helga Hufflepuff, decreed that any house elves who were "freed" and had no where else to go could come to hogwarts for work and the headmaster of the time had to welcome them. It explains why Hogwarts has so many, why they like it there so much, and why both Dobby and Winky both ended up there after being freed by their respective masters (other than Dumbledore's tendency to pick up strays). This means that if Hermione wants to fight for Elf rights, she's starting in the wrong place.

Tonks is so clumsy because she's a metamorphmagus.
It must be tricky keeping everything symmetrical if you can give yourself a pig snout at will, right? And that's likely to make you a little uncoordinated; "two left feet" means "clumsy" for a reason. Not to mention that if she decides she feels like being 5' one day and 5'10" the next, she's likely to forget exactly how tall she is and, again, that's likely to throw you off balance. If she changes the shape of her eyes, she might see things differently and expect her field of vision to be different than it is, and not see something out the corner of her eye that she's about to whack into. So she's a little bit Blessed with Suck.

The only way to produce a Patronus is if you're accepting of Muggles, Muggle-Borns, Squibs, and/or Blood-Traitors

 * Word of God says that the only Death Eater who could produce a Patronus was Snape. Snape was (at least somewhat) accepting of Muggleborns, Muggles, and Squibs, because he fell in love/lust (there is really no denying that his relationship with her wasn't at least part-lust.) with one. None of the other Death Eaters could, because they were all for the slaughter of people with Muggle-blood, Squibs, and those who supported both. Snape, though it's made VERY CLEAR that he doesn't care about any other Muggleborns, Muggles, or Squibs apart from Lily, since he is stated to be very rude towards them (Lily says he calls everyone but her of Muggle birth that dirty M-word), and he is extremely rude to her sister specifically because she is a Muggle. After she died, though, he wanted to protect her memory, and he still at least, supported those of Muggle-birth, as he is shown to hate the "dirty-blood" slurs (calling out Phineas Nigellus). Umbridge is a strange exception.
 * Reputedly, Umbridge was only able to while she held the locket Horcrux. Personally, this troper thinks that Snape was able to because, despite all his flaws, what he did during the events of the books was out of love rather than of hate, which is how most Death Eaters operated.
 * Or Umbridge actually got her jollies from having the existence of others in the palm of her hands. It actually crosses over into Fridge Horror territory when you think of it like that.

The Power of Love DID save Harry - just not Lily's Power of Love.

 * I always thought that was kind of dodgy, surely Lily wasn't the first mother to sacrifice herself out of love for her child? An explanation recently hit me: Snape managed to get Voldemort to make an Unbreakable Vow to not kill Lily. When Lily threw herself in the way of the Killing Curse, Voldemort accidentally broke the Vow causing him to die. Harry's scar is a side-effect of the accidental Horcrux creation.

== An expression of electrical technology that is as or more powerful (and/or as or more simplistic) as a given work of magic, yet simplistic enough to survive from startup to the point where it surpasses the magic, is in fact able to cause magic to malfunction in the same way that magic causes technology to malfunction, and thus the industrial and technological revolutions have affected wizarding society. == As we have so far seen, the likelihood of technology malfunctioning in the presence of magic has a direct correlation between the power and complexity of the magic and technology (respectively) and the probability of both a malfunction in general and how catastrophic said malfunction will be. My guess is that the inverse applies: If extremely powerful technology is "practiced" around sufficiently complex magic, that probability that said magic will fail tends toward 1. Magic, warping reality at a level similar to the absurdity experiments used to describe the hypothetically stupid effects of quantum physics at a macroscopic level, is automatically much, much stronger than any technology available today, but also amazingly more complex in its spells' inner workings.
 * For example, if a wizard had attempted to turn a teapot into a wheelbarrow while the protagonists of the Ocean's Eleven remake set off the EMP bomb nearby, the transfiguration would have failed catastrophically and resulted in, say, a large, lopsided stone washbasin with a spout. However, if someone in the vicinity had attempted a simple candle-lighting charm moments later (during the blackout), using the typical amount of effort for such a spell, the candle would have flared up and taken their eyebrows with it.
 * Thus, technology has not only sent wizards into hiding because it allows muggles to better observe the world around them, but it has also become more difficult for wizards in muggle communities to practice magic. This is not to say that wizards in muggle communities are less adept at practicing magic; on the contrary, they would likely tend to develop stronger baseline magical ability, such as can be seen with Hermione Granger (one of the most powerful witches of her generation) and Harry Potter (a very, very promising wizard who neglects his ability and rarely bothers with practicing finesse in his work), who both spent most of their first seventeen years in modern muggle communities.
 * An additional and significant example of technology affecting wizarding society, and the primary drive behind this guess, is that the most complicated spells have died out because of technology. As spells fall higher on the scale of power, the ratio of power to complexity reaches a point of diminishing returns, and thus they are more easily toppled by technology even though they are more powerful. Creating a basilisk, for example, would now only be possible in certain parts of Africa or the oceans (and other places where satellite coverage is less dense or nonexistent and ground-level technology is lacking), and even then only by being very careful in making sure every step went right, more careful than Salazar Slytherin would have had to have been. If the wizarding community had developed less complex versions of these powerful, complex spells, such as those which might have been discovered or developed by Voldemort, they might have still been able to complete such spells of staggeringly mighty result even to this day. As it is, they just collectively decided that the true means of recreating the effects of these spells had been lost, or that something prevented these old spells from being learned from books without knowledge of the theory behind them (being-transmitted knowledge, in the case of the Interdict of Merlin).
 * To sum up: Technology interferes with magic if the magic is weaker or much more complex. This resulted in wizards being stronger, but the spells they can still cast being weaker.

If Harry had an animagus form, it would be...

 * A spiny mud dauber (a hairy potter), based on the theme naming from other animagi.
 * An otter.
 * A dog, but a more domesticated breed than Sirius' form. He's very loyal (almost unquestioningly so until Book 7), even if it has been trained into him by Dumbledore since age eleven, and he tends to go off halfcocked every time someone throws a (metaphorical) ball or tells him to do or not do something. Also, dogs are extremely normal, and the intense normality of Harry's full name is why the author chose it.
 * A peregrine falcon, or possibly an osprey. What other animal form would be available to a seeker who could perform a Wronski Feint during his early puberty?
 * A James' flamingo because it refers to his father's name and is named after Harry Berkeley James. I also read a fanfic that had this as his animagus form.

The House Cup point values are deliberately skewed to give and take points in greater amounts as students age.
A first year is expected to have a bit of leeway, so they get a few points taken off when they get in trouble. However, older students have gotten used to that sort of point reduction and should know better, so they get more points taken away for infractions, and are given more points (when they are given points) for having supposedly had to use more ingenuity/luck to stand out instead of simply getting points for following the rules.

The Bertie Bott's corporation has a promotional sponsorship deal with Hogwarts.
This is why Bertie Bott's Beans are used as a currency in the video games. They also set up the Bean Bonus Room as part of their promotional campaign.

Hogwarts was cash-strapped enough to have to accept corporate sponsorships during Harry's first few years there. After the whole Chamber of Secrets disaster, the school ended up with even less money for the next year, so they had to accept additional sponsorships from the Pumpkin Pasties and Cauldron Cakes companies. Eventually, the Triwizard Tournament made enough money for the school to do away with corporate sponsorships for the remainder of Harry's time at Hogwarts. They'll be back in a big way the year after Harry Potter and the Deathly Hallows, as the school rebuilds from the Battle of Hogwarts.

Wolfsbane Potion
For a while I thought the Wolfsbane Potion acted as a suppressant. But after some more consideration, it seems more likely to act as a tranquilizer. When Lupin is on the potion in werewolf form, he does little more then fall asleep. In the shrieking shack, the potion does nothing to suppress the werewolf mind, even though he HAD taken it many nights previous. Is the dosage taken on the night of the full moon the only important one? If so, why bother taking it on previous nights? It would probably take a very high dosage for a tranquilizer to knockout a werewolf, which further supports this theory.

Arthur Weasley was put under the Imperius Curse during the First Wizarding War
During Fake-Moody's demonstration, he used two of the three Unforgivable Curses to screw with particular students. The Cruciatus to affect Neville, and Avada Kedavra to get Harry. When Ron mentions the Imperius curse, Fake-Moody says "You're father would know all about that one," implying first-hand experience. He then used the Imperious Curse, hoping to get at Ron, who likely doesn't know this part of his father's story. Consider that Arthur is held in high regard, seemingly almost as high as the Potters and the Longbottoms, yet is shown to be working a dead-end job and have little-to-no money. The high regard comes likely from his actions during the war. At some point, he was captured and placed under the Imperious Curse. Given his connections to the Order, especially the Prewitt family and Dumbledore, his mission would likely have been killing the Prewitts or even Dumbledore. However, in an extraordinary display of will, he broke free of the curse. However, the strain of breaking free left him somewhat...damaged. This is why he is held in such regard.

Other ways to destroy a Horcrux.

 * Dementors: Creatures that easily pull souls from a resisting human body - seems that they could easily take the fraction of a soul weakly tied to a Horcrux.


 * Throwing through the Veil: Any object that has gone through the veil, living or inanimate, does not come out the other side. If the veil doesn't "kill" the portion of the soul thrown through the veil, it will leave it in a place where the soul cannot be reached by any means.


 * "Touch this Object and You DIE" Curses: We do know of at least one object in the Potterverse that has been cursed to kill by a mere touch. However, none of the Horcruxes has this feature, even though Voldermort would have the ability to do so. Since he wasn't above a softer version, that killed anyone slowly if he put on the ring, it would explain this oversight if the soul is killed or the object can't be made into a Horcrux if it kills anything it touches.


 * Poisons about as deadly as Basilisk Venom: If any magical poison is as strong as or stronger then the one found in the fangs of the chicken snake, one should assume it would hold true to any poison equal or greater in strength.


 * Nuke'Em: The shockwave that crumbles buildings, the intense radiation, and mostly the heat that would vaporize just about anything seems like it would satisfy the "beyond magical repair" threshold needed to destroy a Horcrux.

The horcrux inside the locket and Ron
The locket seemingly works on Ron's self-esteem, at least that's what I got out of it, but what if that's wrong... What if the horcrux/locket streamed into Ron's memories every single Harmonian fic ever written. The ones where he's not good enough, where he's too stupid, where he's considered worthless.

The ones where he's abusive, or a rapist, or a Death Eater.

Not only would he have the feelings of inadequacy, but also the idea that, if he was with Hermione, he'd just make her miserable, and hurt her, and with that, he left them. Not only does he feel inadequate, he also is afraid that he'll hurt his friends, not realizing that him leaving hurt more than he would.

When he left the locket's influence, though, he realized that he had the choice to hurt those he loved or not, and he doesn't want to, so he went back.

The Ministry of Magic is a horribly run government
This is partially canon, with it being know that the Ministry of Magic is horribly corrupt, but it is worse then what was explored in the books. We already know that the Malfoys basically own the ministry, along with a handful of powerful pureblood families, likely what remains of an old nobility system. We also know that the ministry was putting up a face of inter species equality, but in effect is incredibly... would it be racism or speciesism? against other sentient beings. The only position that appears to be a matter of any kind of vote (with how much the vote counts seams to be somewhere between "minimal" and none), thus unpopular and very bad people have been able to hold all sorts of power, such as Umbridge. What would seam like very important parts such as random tampering of Muggles objects (just think of how badly that could go?) is both horribly understaffed, but also run by a man who tampers with muggles things himself, that have lead directly to at least one serious breach of wizarding secrecy. They also have few to none good international relations, unable to get any assistance against Voldemort period, with no signs of embassies or departments related to international affairs.

Rebellions have been a constant problem (at least twice over quidditch), yet they let the economy by the ones who have rebelled most, Goblins. The ministry has been overthrown by a group of less then 50 dark wizards using mind control curses. Their appears to be no form of either soft or hard constitution, nor any form of government oversight, which allows them to make one of the two newspapers run what ever they want, able to call full scale tribunals on the cases of underage magic, and make horribly laws that allow the termination of a large percent of the magical population on clearly false information.

Helena Ravenclaw is an illegitimate child
This is mostly to do with her surname. She bears her mother's surname, implying that her mother was not legitimately married to whoever the father was.
 * But if Rowena were married a man with the last name Ravenclaw, it wouldn't be an issue for her daughter to have the same last name. I have my mother's surname because she took my father's when they got married. That's generally how things work. Plus, it explains why the symbol for Ravenclaw is an eagle, not a raven. Maybe her maiden name had something to do with eagles.
 * Or it's possible that Rowena married 'down' - that is, fell in love with a man of lower social class. In which case, he took her surname instead of the other way around. It wasn't completely unheard of.
 * And by 'down', we could mean 'muggle'. Which would also explain Helena's apparent inferiority complex. The truth is that exceptional skills at magic in general have nothing to do with 'blood purity', and do not seem to run in families anyway, as neither Dumbledore or Voldemort's magical family members seem very powerful. However, it seems reasonable for Helena to think her 'averageness' is due to being half-blood, which would explain her issues with her mother.
 * Alternately, of course, she might not have married the Muggle at all, or married him in a Muggle marriage the Wizarding world didn't recognize.
 * Alternately, the four founders were only given those surnames retroactively. The founding of the school would have been sometime in the ninth or tenth century, and family names did not come into use in the British Isles until several hundred years later.
 * There's more evidence for this theory than the surname, or at least evidence for something odd. The books state that Rowena was desperate to find her daughter before she died, but not a single mention is made of the father, either helping look for Helena or being with Rowena as she died, which seems a rather glaring oversight in the history unless this was a subject you Don't Talk About. Even Helena doesn't talk about him! (It's possible, though, that he was dead at the time and thus completely irrelevant to the story.)

There were many other traits - not all of them positive - associated with each house that factored into the Sorting process. The Sorting Hat and staff just didn't talk about them.

 * Gryffindors were known for being brave and chivalrous, but also were capable of being brash, stubborn, and even cocky at times. James and Sirius are prime examples. Even characters like Fred and George were brash in a sort of endearing way.
 * Ravenclaws have a reputation for being knowledgeable and quick-witted, but seemed to have a tendency toward mental and emotional problems - not to mention they had little luck in maintaining relationships (romantic or otherwise) with people. Luna was obviously presented in a sympathetic light, but it's very possible she wasn't all there in the head. Cho had obvious problems handling her emotional issues, and even Roger Davies, a minor character, had hints of being a bit too obsessed with dating girls for his own good (was Fleur's date in Goblet of Fire, asked Cho out but was turned down, and then was seen not long afterward with a new girlfriend in Order of the Phoenix). It's also notable that it took both Cho and Luna (if you're following the movie canon as well) more time to find husbands than it did for anyone else.
 * Hufflepuffs are seen as hardworking, trustworthy, loyal, and fair, but they tended not to stand out without extra effort. That may indicate a lack of luck, a lack of charisma, or both. This may or may not have been part of Cedric's reason for entering the Triwizard Tournament, but that's a completely different WMG.
 * And then you have Slytherin. Cunning, strategic, and ambitious - in other words, people that knew what they wanted and also tended to know how to get it. Let's forget the reputation for turning out dark wizards for a second and observe some of the personality traits. Yes, Slytherins tended to be more willing than others to step on people in order to get what they wanted; but Slytherins valued more than anything their connections - whether it was with their pure-blood ancestry or great wizards and witches around them. As a result, though, they seemed to be an even more closed social circle than the other three houses. Occasionally you would see Gryffindors interacting socially with Hufflepuffs and Ravenclaws, and vice versa. But Slytherins only interacted positively with other Slytherins.

Eileen Prince was bullied by Gryffindors during her time at Hogwarts.

 * It's a known fact that Gryffindors not mature in their traits could be quite brutal to people they disliked. One would imagine that being captain of the Gobstones team at Hogwarts was somewhat analogous on a social totem pole to being the leader of the Chess club at your local muggle high school because Gobstones is, essentially, wizarding marbles. It seems strange that Snape, on his first train ride to Hogwarts, shows almost immediate contempt for Gryffindor unless there was some prior experience there.

Neville took the herbology professor job because he had a kid

 * Word of God says that Neville was an auror for a while before he became a herbology teacher. Although he was shown to be good at both, it seems like a strange jump in careers. However, if he found out his wife was pregnant, he might not have wanted to be in such a dangerous field, not because he was worried for his own safety, but because he didn't want his kids to grow up without a father, the way he had to.

General Winter is the codename of a line of Russian Wizards that make use of weather control against invaders
Isn't it a bit strange that both Napoleon and Hitler got the worst possible weather for their invasions?

The previous Prime Minister tried to kill Fudge on purpose, and was Margaret Thatcher
This is due a previous WMG that supposed a crossover. In this one, Margaret Thatcher already knew of magic for eleven years, and when Fudge announced he was the new one she proved herself a wonderful judge of character and tried to help Wizarding Britain by killing him. Sadly, Fudge wasn't so easy to kill, and survived, with the results we all know. On why Fudge called her a 'he'... Guys, smarter people than Fudge mistook Margaret Thatcher for a man...

McGonagall found Moaning Myrtle's body in the toilet...
...when she was a student herself in the 1940s. Olive Hornby was the last person to see her alive, but we're not sure who found her dead. McGonagall's the right age, she knows things about this and...mostly it's just for symmetry with the "Claude's ghost is haunting the bathroom" WMG on the Degrassi page.
 * Jossed. McGonagall was a student in the 1940s, but she started in 1946 (birth date was 1935). Myrtle died in 1942 - McGonagall would have been about 7.

Death Eaters Killed Mr. and Mrs. Evans
Lily and Petunia's parents were killed by death eaters, either as part of random muggle killings or directly because of Lily's involvement in the Order. Either way, this explains why Harry has no maternal grandparents, and also explain why Petunia, in addition to jealousy of Lily's powers, has such a fervent hatred of the magical world—she, like Harry, lost her entire family to Voldemort. But instead of blaming Voldemort, she blames the entire existence of magic and prefers to deny its existence and live a "normal" life.

Hogwarts Castle was initially built as a refuge for wizards and witches.
The year 1000 AD, the year of the school's founding, was mainly dominated in Britain by the blood-soaked battles between the Saxons, Britons, Vikings, and anyone else who cared to join. Naturally, the wizarding folk of Britain would want to avoid this, and they did so by hiding in the spacious, well-fortified, spell-soaked castle of Hogwarts. In time, the refuge that was Hogwarts Castle saw the arrival of children, and they needed to be taught the magical arts. The founders themselves began giving lessons to some of the children, and once things in the mainland calmed down, Hogwarts morphed from a stronghold to a school.

No magical creature in the wizarding world existed before the myth or myths attributed toward it.

 * Herpo the Foul was inspired by Pliny the Elder's description of the King of Serpents, and "invented" the Basilisk via a spell-laced ritual.
 * Some Saxon wizard, wanting to safeguard his riches, created a fire-breathing reptile in line with local tales, and others capitalized on it.
 * Several ancient Greek wizards, in jest at first, recreated various monsters from tales told to them at a young age.
 * Several sentient beings were made in model with several old tales, but they ended up rebelling, and became races in their own right.
 * A few witches and wizards, feeling malicious, recreated mythic diseases from Muggle ghost stories, which rebounded horrifically.
 * Of course, many magical creatures were made that had no connection to myths; in fact, a lot were made to satisfy a particular wizard's need, or on a whim.
 * Naturally, each and pretty much every one of these creatures, magical as they were, went mostly wild.

The giant squid in the lake at Hogwarts is there for a reason.
It might be guarding something within the lake, or was made to keep the violent aquatic residents of the lake in line. Or maybe it really is Godric Gryffindor, who's a giant squid Animagus, and returns to his former self on the eleventh hour of every night.
 * It could be a tentacruel. Not sure what a Japanese magical creature would be doing in Britain, though.
 * Since I don't think they there are freshwater squids it might be another giant Kelpie that likes to think it's a squid.

Salazar Slytherin was descended from snakes.
Or was himself a snake, made into a man. There seems to be little other explanation as to why or how he'd be able to pass the gift of Parseltongue to his distant descendants, when it can be learned just as well. Some other ancient wizards might've once been serpents as well, such as Herpo the Foul.

"Avada Kedavra" was one of the first spells.
While many spells have roots in Latin or English, the Killing Curse (according to J.K. Rowling) stems from an old Aramaic charm, used to cure illnesses. Given etymology, the Killing Curse could very well have been discovered by accident. "Alohomora", hailing from the Sidiki of West Africa, might also be quite older than most spells.

The "green flash" people see sometimes at sunset is actually wizards far far away on the horizon trying to kill each other.
Just because.

All the Horcruxes (except Harry and possibly Nagini) had malicious magic placed on them

 * The ring is obvious, that was a normal curse plus probably some sort of compulsion to put it on.
 * The diary included some of Voldemort's memories in addition to his soul (Remember, memory embedding is done all the time with paintings and whatnot. Presumably that's a spell.), and a spell to suck someone's soul into the Horcrux and let the memories and Voldemort's soul back out.
 * The locket is interesting. Many people assume that was purely the effects of being around Voldemort's soul...but that clearly doesn't make sense, as Harry's been around Voldemort's soul his entire life. Also it seems strange that a soul could rear up and attack people like that. So there seems to be a specific spell on it causing it to put horrible thoughts in people's ears.
 * The one on the Diadem of Ravenclaw? It's the DADA position curse! Assuming that Voldemort hid it on his way down after being rejected for the position, it makes perfect sense. And explains why he hide it in Hogwarts...perhaps it has to be located there to work. And yet a check for malicious magic won't find it, hidden as it was in the Room of Requirement.
 * The cup is unknown, it didn't show up long enough, but would possibly attempt to make people drink from it at some point, perhaps poisoning them. Although that's a retread of the ring.

Voldemort did not hide the Diadem of Ravenclaw in the Room of Lost Things
There's no possible way to think 'No one has ever found this room before' when looking the Room of Lost Things, which is full of a thousand years of junk. Clearly, people are in and out all the time. (In fact, there's a real question of just how much stuff got there, even with house elves using it as a trash can.)

But instead, let's look at the other way: You get the Room of Lost Thing by asking for somewhere to hide things. Perhaps the Room of Requirement is very unoriginal, so it can't think of anything to fill such a room with. So when you ask for that, it goes and gets everything anyone ever left behind in the Room of Requirement, and piles it up.

It puts the junk in the same location each time because people inevitable want to find their stuff again, creating the illusion that each thing has a 'place' and the Room of Lost Things exists all the time and has that stuff in it. But it's just recreating it from the stuff that house elves threw away and other people left behind in the DA room and stuff like that.

In other words, if someone leaves a textbook in the DA room, it would show up in the Room of Lost Things somewhere next time someone called that up. And, obviously, it would show back up in the DA room also if someone recreated that. When no room is active, it's in Hammerspace somewhere. (For some Fridge Horror, imagine what happens when you come out of a Vanishing Cabinet in Hammerspace.)

So basically Voldemort thought he found some other room, and never realized the Room of Requirement was anything other than that specific room. He hide the Diadem in 'that' Room, never realizing that he had entirely created the place out of thin air. And it got used the next time someone created a room filled with unspecified stuff.

This raises some interesting questions of what room Voldemort thought he found. Considering he spent years looking for the Chamber of Secrets, perhaps he first found 'The Room to Show The Heir of Slytherin Where the Chamber of Secrets Was' or something like that, and the Room, in fact, showed him. Or perhaps he was also looking for a secret room to have to do with Ravenclaw, which is why he left the Diadem there.

The wizard in the portrait in the muggle prime minister's office is an ancestor of Dolores Umbridge
Well, the only description we get of him is that he's small, ugly, and frog-like, and he announces himself with a distinctive cough...

The horcruxes have progressively smaller soul fragments
The first time Voldemort made a horcrux, his soul probably split directly in half. So half went into the first horcrux (the diary?) and half stayed in Voldy. Well, that means each horcrux has less and less soul—the next would only have 1/4 of a soul, the one after that only 1/8, and so forth. The earliest horcrux, the diary, was sentient in its own right and could possess people. The ring, which was the second, was able to effectively kill Dumbledore. The third, the locket, was able to exert evil influence on Ron but couldn't act directly. So Harry, being the last horcrux, has a very small soul fragment, which is able to talk to snakes and has flashes into the mind of the original, but isn't very powerful on its own. Of course, by extension Voldy himself would have the same size of soul fragment as Harry, but perhaps because it's in the original body / has access to the others, it's more potent?
 * Voldemort did become less human as time went on (as lampshaded by Dumbledore). His brain was probably still affected by the tiny soul fragment because there was nothing else in his body to compete with it - it was whispering/croaking in a quiet environment. In contrast, the Horcrux fragments each had to compete with an existing, complete soul to be noticed by the person they were trying to affect. Even the book fragment couldn't do much until Ginny had poured her own self into the diary, giving it a connection to her. The locket mostly magnified fears that the host souls already felt, and the ring had help from whatever protective curse Voldemort had put on it when he hid it.

A Duckbilled Platypus is a magical creature
But the magical government of Australia managed to screw things up so badly the ICW has given up on ever getting their existence back under the Statute of Secrecy. It helps that they are rather hostile and don't do anything that is obviously magical from a distance.

The Fat Friar is the ghost of the Real Life "Grey Friar"

 * The term eminence grise, essentially meaning The Man Behind the Man, comes from an influential advisor to Cardinal Richelieu who was known as the "Grey Friar"—basically a figure who organised The Terror from the back room. Hufflepuff House, as the trope they gave their name to implies, are never in the spotlight and nobody knows what they're supposed to be good at, and the mascot of their house is similarly obscure. So, what are Hufflepuffs good at? Getting stuff done without drawing attention to themselves. Keeping a low profile, and encouraging people to think of them as Living Props, if they think of them at all. Getting their powerful friends to do their dirty work. Kind of a change of image from the "bumbling badger of mediocrity", no? Suddenly, I find myself wondering what shadowy intrigues they managed to orchestrate while Harry and Voldemort were causing all that noisy commotion... -John Nye
 * So they're something that looks cute and harmless while secretly being totally badass? Makes even more damn sense if you know anything of the true nature of the honey badger.
 * Looks cute and harmless while secretly being totally badass? Sounds like Nymphadora Tonks to me! (Who incidentally, is a Hufflepuff)

A Lot of Muggleborns from the 80s can see Thestrals
The ability to see Thestrals is caused when you see someone die and understand exactly what death is. Magician Tommy Cooper died on live television of a heart attack, and his death was announced later. Now, who's to say that quite a lot of young Muggleborns weren't watching? The reason Harry didn't, you may ask? He was 2-3 and the Dursleys are bastards. I'd expect someone Percy's age to see them, however.

Harry did end up getting that tattoo of a Hungarian Horntail on his chest.
And how? Completely unintentionally! Voldemort's first Avada Kedavra to Harry hit him in the forehead and gave him his lightning scar. The second AK, however, which Voldemort cast in the forest, hit Harry in the chest, and in the process carved the macho Hungarian Horntail with his spell.

The wizarding community allied with the Dementors in Roman times.
It fit with the Roman view of punishment. It would also explain how medieval Muggles confused the innate, neutral abilities of the wizarding community with the dealings with evil spirits that people traditionally referred to as witches had.

Avada Kadavra is pure magic.
Magic interferes with electrical machines like an EMP. Humans also have many electric signals keeping us alive, but we are far more resilient and will survive an EMP blast as all our electronics are fried. However, given enough, even humans will die, although it takes a LOT. Avada Kedavra is just a bolt of pure magic. It doesn't have an intended purpose, it just is a green blob in it's purest form. It takes a lot of will to cast it, with the only piece of will strong enough is the desire to kill. In theory, a wizard could make it appear if they tried hard enough, but no wizard know it's true nature, and no one is testing it.

Magic is fueled by calories.
This explains why the students of Hogwarts eat three enormous feasts every day, and none of them, in fact no wizard that we see, is severely obese. A great many wizards are skinny, and those few who are somewhat overweight are not using their powers to their full potential, resulting in a buildup of magic and resultant fat. Such people include Molly Weasley (kills Bellatrix with relative ease when she gets serious) and Neville Longbottom (whether he's actually overweight is a matter of interpretation, but he's definitely not meeting his potential in the early books).

If any Death Eater splinched when summoned by Riddle, s/he got AK'ed.
"What? Not determined enough to get here?"
 * Voldemort was a Complete Monster but not the worst boss, as far as Complete Monster villains go. If anything, he didn't like killing those that he felt could be the slightest use to him. (Which may explain why he tried to recruit James and Lily as well as Neville before deciding to kill them outright.) He was probably more likely to torture or humiliate someone he felt had failed him. Hence, Crucio when a person had already left pieces behind. Yeeeeowch.

The basilisk in the Chamber of Secret is not there to kill Muggle-borns.
Why? Because it somehow manages to kill only one of them in dozen times it is let loose. Either that's some really crazy coincidences, or it's deliberately petrifying people instead of killing them. And the one time it does kill a witch that witch appears to have accidentally opened a door and looked straight at it, so that might have been an accident, or perhaps Riddle deliberately had it to kill that one time, as he was making a Horcrux.

Now, yes, it is apparently roaming around talking about killing people...but then fails essentially to kill any wizards, which raises an interesting question: Maybe this is all a horrible misunderstanding, or deliberately distorted history, and Salazar Slytherin put there to kill Muggles, not Muggle-born wizards, in case they invaded? And, for safety, it reversibly petrifies any Muggle-born wizards until which side they are on can be determined.

Lily and Petunia Evans' parents were Squibs.
Which is why they were so extremely happy that Lily was a witch, and may explain why Lily was allowed to use magic at home (they knew how the tracking system actually worked).

Lily and Petunia are actually the same person.
In some of of literal split personality way. Maybe it was from spontaneous magic, or maybe Snape did it deliberately, but this is why Lily is all good and Petunia is all bad.
 * There are a few issues with this. 1, it's not fair to say that Lily is all good (we only see idealized images of her from Harry and Snape's memories) and that Petunia is all bad (she'll never win Aunt of the Year, but she loves her immediate family and took Harry in when she didn't have to); 2, it would have had to happen when they were younger than 11 because Petunia has hated (or at least been jealous of) Lily's magic since she found out about it and both existed separately when they were in school and both shortly thereafter got married and had sons; 3, Mr. and Mrs. Evans would probably have noticed that they used to have one daughter but suddenly have two and, being muggles, thought that was a bit off; and 4, how would that even work? If it were intentional magic, it'd have to be some ancient, forbidden, dark magic (you can't just create a person out of thin air and you'd have to make up at least half a person twice to do it and would splitting someone into two involve splitting the soul? Would that make one or both of them a horcrux? I don't think Snape killed anyone in his childhood and the way Voldemort's soul going into Harry's body let him speak parseltongue seems to imply that the non-magical half would at least have some magic which Petunia definitely does not) and splitting a person into two people does not seem like the type of magic that can happen accidentally because it would be pretty common if wizarding babies could do it and splitting someone seems like it would take a lot of effort, power and concentration.

Harry and Ginny moved to Ottery St. Catchpole to start their family.

 * Harry obviously inherited 12 Grimmauld Place from Sirius, but he likely wouldn't have wanted to stay and raise a family there, given all the bad memories - to say nothing of the ghost of Walburga Black and the fact that the house itself was creepy and depressing anyway, even before the War. Not to mention that, in Ottery, Harry would have had the room and the pocket to build a much nicer house, where he could also be close to his in-laws and bring the children up around wizards instead of in a wizarding house shoehorned into a Muggle neighborhood. Also, the factor of Ginny being a former professional athlete and Harry being, well, Harry, living in London would have gotten them way more attention than either one of them would have wanted. So they moved out to the country. As for Grimmauld Place? Harry would use it as a rest stop of sorts if necessary if his work required him to stay in London for any period of time.

At one point in his life Ollivander picked up a muggle pencil...
...and immediately said "Ah, 7.5 inches, firm, red cedar with a graphite core."

Snape is the Heir of Grindelwald.
Grindelwald raped a British pure-blood woman sometime during his reign of terror. This woman was engaged to a guy from the Prince family, whom she eventually married. She gave birth to Grindelwald's child, naming her Eileen. Eileen went on to marry Tobias Snape, and then they gave birth to Severus.

That's right. Gellert Grindelwald is actually Snape's great-grandfather. It would explain Sirius's comment that Snape "knew more curses when he arrived at Hogwarts than half the kids in seventh year" (assuming he wasn't bullshitting to make Snape look bad), since he inherited it from dear old great-grandpa Gellert.

Stop looking at me like that. You all think it's cool, I'm just saying it.

Magic is nothing but a misunderstood remnant of ancient alien technology.
The phenomenon called "magic" is all that remains of the technology from an alien race visiting the earth thousands of years ago. The aliens, much more advanced then even modern men, set up a quantum manipulation field, with which they could alter the environment and, given enough energy, even create things seemingly out of nothing. The energy sources of this field are scattered all through the world, in the form of strange artifacts or even geological formations, such as hills, seas or old rocks. A lot of those sources diminished in power or even disappeared, but the biggest source still remains: the Moon, which had its core altered to relay and power the alien technology.

After the aliens disappeared, human beings very gradually managed to tap into this quantum manipulation field. They did this using trial and error, inventing incantations that resemble the old auditory commands given by the aliens. Human beings generally need wands to focus their own life force to make the field aware of them. Also, not all people have this ability, only the descendants of those the aliens experimented with. The centaurs could also be the result of an experiment gone haywire, involving combining human beings with horses.

Certain combinations of chemicals can also cause interactions with the field, which is the cause of potions. Lastly, most of the strange creatures are the descendants of animals the aliens altered for their purposes.

Blaise Zabini's mother is a master potioneer and/or very adept with the Imperius Charm.

 * This might go a long way toward explaining Zabini's presence in the "Slug Club" in Half-Blood Prince. Even for Slughorn it seems a bit dubious to associate oneself with a guy whose claim to fame is that his mom keeps coming up with money after her rich husband mysteriously snuffs it. On the other end of that, at about the sixth husband, someone had to have gotten a clue and thought, "But the first five guys this lady married all wound up dead..." Which indicates that, in order to keep doing the same thing over and over again without getting caught, there was likely some spellwork involved. Which dives right into Fridge Horror if you consider that Blaise himself might have been conceived under the effects of a Love Potion.

Ariana Dumbledore's eyes were green.

 * That's why Dumbledore frequently tells Harry that 'he has his mother's eyes' (namely green eyes)-because looking at Harry reminds him of Ariana.
 * HPWiki sez Ariana's eyes were bright blue/dark.

The Statute of Secrecy was due to the Enlightenment
The fact that Wizards are hiding because 'muggles would expect us to solve all their problems' was explicitly stated at one point, despite the fact that various other people seem to think it had to do with witch burnings, although it's also pointed out that this is mostly wrong. So let's supposed the first is true. The Statute of Secrecy was first created in 1689 and signed into law in 1692. Let's check what happened in 1689 to see if we can pinpoint it.

Isaac Newton was elected to English Parliament in 1689.

So he then spent his entire time there demanding that Wizards work for the Crown, specifically demonstrate how magic worked, so that everyone eventually could have magic. Until he could get everyone magic, he proposed some sort of draft for wizards where they had to work for the government. This eventually reached the point that the Wizards had to Obliviate the entire English government (Which resulted in history remembering Isaac Newton as doing exactly nothing in Parliament, as every single thing he did was connected to magic.), and forming their own government and a sort of 'treaty' with the Muggles three years later.

Dementors are The Corruption.
Remember what Lupin said about dementors? They turn you into "something like itself." What if that was literal? It's mentioned that they breed... what if the Kiss, if extended, could turn you into a dementor?
 * Holy crap this theory makes way too much sense. Dementors seem to have some form of sentience and independence, as they seemed quite content to serve as the ministry's enforcers before Voldemort came along. What if a dementor is a person that has had their own soul sucked out and in turn becomes a soul-sucker in the attempt to fill the void of their own soul not being there? That seems to fall in line with the Fate Worse Than Death wizards say that the Dementor's Kiss is. After all, wouldn't it be more efficient (and actually somewhat more humane) to execute the most severe criminals by Avada Kedavra or something? But forcing them to live the rest of their existences as a Dementor that (up until post-war) does the Ministry's bidding? No wonder the lot of them turned against wizardkind the first chance they got.

Chamber of Secrets had rape overtones in its narrative that may have been intentional.
Think about it. Young girl forms a trusting/confidant relationship with an older male 'friend' she doesn't know much about - a 'friend' who gets his jollies on domination and sociopathic behavior, by the way, and is willing to humor this little girl for as long as it suits his needs. After some of her encounters with him, she blacks out and wakes up not knowing what happened. She feels dirty inside and can't really explain why. And at the end of it all, she ends up being kidnapped and lured by this 'boy' into a place called The Chamber of Secrets, where she is meant to be used for his ends. For God's sake, the entire thing plays out like something straight out of Law and Order Special Victims Unit.

Note, I am not saying that Ginny was physically raped by Diary!Tom Riddle, although I certainly would not have put it past him. After all, Riddle was said to have done something to one of the orphanage girls that was extremely traumatic and about which we readers can only speculate. But the interaction between Riddle and Ginny plays out like an allegorical rape. Which also explains Ginny's reaction to the Dementors in book 3. By then, she'd had about two or three months to process the gravity of what had happened to her, which is enough time to realize how bad it was but not enough time to start healing. She's also Demoted to Extra in books 3 and 4, which may indicate that it took her a couple of years to get over her own personal demons even before Harry started having some real issues in books 4 and 5. Then Harry falls in love with her because she's the only person he knows that has gone through nearly as much interaction with Voldemort as he has.

J.K. came out on record as saying that Ginny was Harry's 'ideal girl', and, as she also said that Harry, by his mid-teens, had less sexual experience than other boys his age - make of that what you will. What this troper makes of it is that Harry didn't have a 'type.' He didn't have nearly enough experience with girls to have a 'type' that he liked in particular. He was physically attracted to Cho, but the relationship didn't work once it got rolling because he was seeking from her what he eventually found in Ginny - someone who had a small understanding of his burden. Note how he gets over Cho rather quickly; he knew that she didn't - and couldn't - get it. But Ginny did because of the above experience, and that's why she and Harry ended up together.

The Resurrection Stone works...
...But not in a very useful way. It pierces the veil, allowing someone to pull someone they love back from death...but sends the user towards death, because there is Equivalent Exchange. You can't 'create' life using magic, but you can 'swap' life. (Which is demonstrated in the similar example of Ginny and the diary. And note the Resurrection Stone returnees in Deathly Hallows are explicitly compared to the Riddle from the Diary.)

So if both people love each other equally, they're each pulling each other to life, so they both end up in a sort of half-life. Which, as we were told back in the first book, is not a state that normal people can stand. Hence the suicide in the Beedle the Bard tale, although it's been a bit simplified and didn't say the user of the Stone was also 'sad and cold'.

Harry brought four people across, which resulted in five people sharing one 'life', so we're probably pretty lucky he only did it for a few minutes, or he would have become fairly sad and cold and suicidal...hey, wait a second. 'He felt a chilly breeze...his body and mind felt oddly disconnected...'

Meanwhile, there is one circumstance where the resurrection stone does work. If someone tried to bring back someone they loved, but who didn't love them back, the stone would work perfectly. They'd succeed in pulling that person to the side of life, while trapping themselves in death.

Snape altered his memories to make himself out to be the victim
Memory charms can be used to alter memories as much as delete them over the years he created his "abusive" father so people feel sorry for him and he never had a friendship with Lily, he was just a stalker after she and James got together and James being a protective boyfriend told him to stay away, Snape simply changed it to make James and Sirius into jerks who bullied him for no reason. With his memories changed Snape beileved his own version of what happened leading to his betrayals.

The Philosopher's Stone was purposefully easy to get
The teachers didn't want everybody to die (which tends to happen to people who don't have access to the stone) but realized to pointlessness of trying to talk Flamel or Dumbledore into releasing it, so they made the obstacles purposefully easy to pass. Also, I notice that potion room only looks stupid because we all know that the potion pointed to is the one that works. Dumbledore presumably didn't check, and either assumed or was told that it was there on the off chance that it could get someone to drink one of the potions.

Aberforth did not get in trouble for screwing a goat, but for cursing a Muggle sports team.
In fall 1945 he was visiting a friend who had moved to the States, and said friend (in the Muggle Liaison department) talked him into going to a baseball game. He tried to bring a goat along, and was told to leave. He jinxed the Chicago Cubs in his anger. It just so happened that there was a local Muggle tavern keeper who had goats, a few Muggles escaped the Memory Charm, and so a legend formed around the Muggle tavern keeper.

The Dusleys were tongue-tied into keeping the truth from Harry.
In "Philosopher's Stone", when Hagrid lashes out at the Dursleys for not telling Harry anything, Vernon Dursley whisper "something that sounded like 'Mimblewimble'". Mimble Wimble is the incantation for the tongue-tying spell and in a later book Dumbledore tells Harry that he wanted Harry to grow up as normal and happy as possible, which is why telling him the whole Horrible Truth was stretched out over seven books.

The Marauders stole the "Half-Blood Prince" potion book at one point, which led to the confrontation in the flashback.
In the flashback in Book 5, James is shown to know the "Levicorpus" spell - which was created, of course, by Snape. Lupin mentioned once in passing that the spell enjoyed a "vogue" at one point during their Hogwarts days, which could indicate that James and Sirius, who were explicitly said by Hogwarts professors as being precursors to Fred and George Weasley, showed people the spell ("Hey, look what I can do!") in an effort to garner more popularity. While, of course, Snape stewed in some corner because James and Sirius were getting kudos for the spell he created. In any case, at some point, they perused Snape's book and saw the note for the "Sectumsempra" spell. ("For enemies.") They likely didn't know what it did, but James at least knew that Snape had some weird company and was way too fascinated with the Dark Arts. It would be tantamount to looking inside the journal of the weird kid at school and finding gun schematics. So James and Sirius might have had it at the back of their head that Snape may snap and go on a killing spree one day, which may have had something to do with why James eventually left Snape alone after a while.

Magic spells are programs/scripts, and Taboos are made using alias.
No, I haven't got lost looking for Dr. Strange, this is based on the way spells are used.

Every spell, even if it's non-verbal, has a name that must be said or thought to 'run' the spell. Instead of teaching kids to focus on a desired outcome when doing magic, schools teach them to use defined magic words. (Apparition is a notable exception, but it is shown to need a lot of practise and careful focus to avoid disaster.) Spell names are shown to work well even if the person saying them has no idea what the spells do.

Snape created spells as a student, including Sectumsempra and Levicorpus. Either those spells always existed and Snape managed to guess the names, trying them out on nearby students as he went, or he defined what the spells did and then gave them their names. The latter is more likely.

The name for a new spell shouldn't be a real English word, or English wizards would risk casting it by mistake. A short Latin phrase (e.g. "expecto patronum"), or even a deliberately miss-spelled and mispronounced English word (e.g. "Ridikulus"), is ideal.

If desired, whoever creates the spell can add other conditions besides the name. For example, most spells require the caster to be holding a wand, while some (including Lumos) just need the wand to be nearby. Presumably a basic wand check is included in most magical programming libraries.

The spell used to make a word Taboo is actually a wizarding version of the Unix alias command. The target word (e.g. "Voldemort") is aliased to a spell script (e.g. to kill nearby protective spells and summon some Snatchers). As long as none of the spells in the script does a wand-holding check, it will run any time the word is said by a magic user.

Presumably, whatever spell is used to create Taboos is pretty advanced, otherwise it would be a popular prank in wizard schools: imagine what would happen if you aliased "Wingardium" to a spell for making fart noises, just before the first years' first Charms lesson.