Common Crossover

Some fandoms just mesh well. The timelines and continuities can be made to fit without much difficulty, they might have similar premises or ideologies, and they have characters that you just know would love (or hate) to meet each other.

Some fandoms are so accessible that they are crossed with just about everything else.

Related to Fandom Specific Plot. A common form is the Doppelganger Crossover.


 * Buffy the Vampire Slayer and Doctor Who cross over so often in fics you can easily start mixing canon from both in your mind. The Tenth Doctor has been paired with Faith in one fic, and there's a Jack/Ianto/Dawn fic out there.
 * Technically, as of Buffy Season 8, they are actually in the same universe.
 * Halo and Mass Effect. Both Sci Fi videogames with Badass Space Marines killing aliens and saving Humanity from extinction.
 * The ISO Standard Anime Example: The Fuku Fic.
 * Ranma One Half in general has lots of crossovers.
 * The large number of Sailor Moon crossovers with Gundam Wing, which typically pair the Senshi and the Gundam Pilots romantically. This is presumably because Wing, by way of its Bishonen male cast, served as a Gateway Series to get girls into the Humongous Mecha genre. And the fact that both of them aired on Cartoon Network's Toonami block around the same time. This could explain why there are so many Sailor Moon/Dragonball Z crossovers as well.
 * House Fanfic is famous for its crossovers. Notable ones are Batman, Angel, Bones, and Doctor Who. Oh, and a few with Firefly, including one with River (where she really sparks his curiosity due to how strange her case is (it's never explained how she got there)).
 * There is a LiveJournal community specifically for crossovers between Heroes and Supernatural.
 * Smallville/Batman, especially Bruce/Lex and/or Bruce/Clark. Of course, the fact that there were plans to bring a young Bruce to the town helps matters a bit.
 * Xander (or, less frequently, Willow or Dawn) gets sucked into a dimensional rift etc., and ends up on Serenity.
 * Stargate SG-1 crossovers are so ubiquitous in the Buffy fandom that in many cases they're not even labeled as crossovers unless they cross with a third fandom.
 * There's a Halo/Buffy/SG-1 fic where Xander went as John-117 on Halloween (the timeline problems there are never addressed) and things change... a lot. It's good if you can ignore the timeline problems. Oh, and Xander actually remembers Jessie and actually still has his death as a source of grief.
 * It's not so much that it does mesh well with everything as that everyone and their cat has heard of it, but Harry Potter has been crossed over with nearly everything. There's one Harry Potter/Disney's Aladdin crossover, completely disregarding the huge time difference and the not exactly friendly attitude Agrabah would have towards wizards once it was not only a Muslim city, but a Muslim city that has "getting hugely screwed over by a sorcerer" in its recent history.
 * Fullmetal Alchemist/Harry Potter. For no real reasons other than that both have involved the Philosopher's Stone and take place in fantastic versions of European countries.
 * And in the Anime/Movie Ed travels to an Alternate Universe which could easily be changed to the HP one.
 * The Veil of Death from the Department of Mysteries is sometimes also used as a link to the Gate of Truth, and as well-written stories such as Penance can attest, it can work to a strong degree.
 * Harry Potter/Twilight, naturally. Someone in the story will usually comment on how much Edward Cullen looks like Cedric Diggory if they aren't revealed to be the same person.
 * Harry Potter/Naruto. Bringing in the characters as transfer students is more than just popular, but numerous stories where Harry discovers he's an Uchiha/Hatake/insert-bishie-indicating-surname-here (or is raised as a member of that family). Team Seven (or just Kakashi) also seems to get themselves hired out as long-term bodyguards often enough for Tsunade to pay off every single gambling debt she's ever had, plus interest.
 * It's worth noting that even among the more serious stories here, the two universes have plenty of common similarities - a singled-out Chosen One, a snake-themed villain with an obsession for immortality, a school of special arts, a group of three young heroes the same age (two male, one female), a long-running myth-arc, Loads and Loads of Characters...
 * For some reason, WALL-E tends to get crossed over a lot with Transformers.
 * Battlestar Galactica gets crossed with any Sci-Fi going eventually due to the Lost Colony premise. For instance, the refugee fleet entering Star Trek's United Federation of Planets with the resulting political fallout and attacks by the Cylons is a common idea. Even given this Galactica/Stargate fics are common as mud.
 * Strangely, the number of oBSG/StarWars crossovers can probably be counted on one hand, even though the former was very heavily influenced by the latter.
 * Naruto and Bleach. Because they have the same audience.
 * Naruto in general really. As of this writing it has over 11,200 cross-over stories in its crossover section on FF.net, plus however many in the main section. Naruto fits just about anywhere, apparently.
 * Naruto and One Piece, if only for the Ninjas vs. Pirates.
 * Maximum Ride and Twilight seem to get crossed over quite a lot for such an odd combination.
 * The FF.net crossover listings for G.I. Joe have many stories that cross over with X Men Evolution. Most of them are written by Red Witch. Most of the others are "set in the Misfit Universe", which means based on Red Witch's on-going series. She has several long stories, and dozens of one-shots which all spring from the premise of G.I. Joe rescues Toad after Magneto throws him out of a plane after the end of the second season, leading to the entire Brotherhood becoming unofficial wards of G.I. Joe. Insanity ensues, though there's also been quite a bit of drama and tragedy as the series goes on.
 * A crossover of yesteryear; Highlander and Forever Knight. There were a lot of those.
 * Phoenix Wright and Trauma Center are both over-the-top DS games about a relatively ordinary profession. Both are Twenty Minutes Into the Future, and both take place in California (or Japan in the JP versions). Though it's generally agreed they fit well together crossovers are surprisingly uncommon.
 * Phoenix Wright also goes well with Elite Beat Agents, probably because both are surprisingly well-Americanized DS games featuring Large Hams with Anime Hair. Heck, one such crossover is even on the Fanfic Recs page!
 * Unsurprisingly, there's also a fair amount of art crossing it over with Ghost Trick... this is saying something, since Ghost Trick's fandom hasn't really gotten fired up yet.
 * Doctor Who has a face that's 'launched a thousand ships'. Travel through time and space tends to facilitate crossovers with anything not too cartoonishly illogi- oh, who are we kidding?
 * And for the anime/manga version of this, see Tsubasa Reservoir Chronicle.
 * And for the Disney/video game version, see Kingdom Hearts.
 * And for the Toku/Japanese version, see Kamen Rider Decade.
 * And for the American version, see Quantum Leap. Double points that it's perfect for writing a Fix Fic.
 * The Cthulhu Mythos fits well with anything vaguely fantasy, horror, sci-fi, or mystery, from Sherlock Holmes to Dungeons and Dragons to the Marvel Universe. Hence Cthulhu Tech. There was even a Batman Elseworld that centered around Arkham Asylum crossed over with the Cthulhu Mythos, making it a professional version of this trope.
 * The IDW comic book series Infestation 2 sets Lovecraftian threats against characters from Transformers, Eberron, Teenage Mutant Ninja Turtles, G.I. Joe, and Thirty Days of Night.
 * Supernatural actually gets crossed with a lot of stuff, but most often with Smallville (which almost always includes Dean/Chloe, though there's an occasional Sam/Chloe or Dean/Lois fic out there) and Buffy the Vampire Slayer (almost always including Dean/Buffy, Dean/Faith, or Sam/Faith, though some Sam/Willow, Spike/Dean, Angel/Dean, and/or Spike/Dean/Sam fics show up sometimes). The number of crossovers with Doctor Who, Torchwood, and Heroes are growing rather quickly. Crossing with Dark Angel is also obvious for the Doppelganger Crossover.
 * Superwho (Supernatural crossed over with Doctor Who) has almost a fandom of its own. Apparently the writers of Supernatural caught wind of this, since they named a new character "Amy Pond".
 * It can be considered a Doppelganger Crossover: Mark Sheppard played both Crowley in Supernatural and Canton in Doctor Who.
 * Superwholock (Supernatural crossed with Doctor Who crossed with Sherlock) has become increasingly popular, uniting Wholock (see below) and Superwho in one all-encompassing fandom. Merlin and Harry Potter may or may not come along for the ride.
 * The shows in the DCLAU and Nick Verse since the rise of online fandom are crossed over constantly regardless, as they are all set in the same rough time period and genre (Kid Com) and most people in their target age groups watch multiples of them and thus have the knowledge to use all the characters in cross-overs:
 * I Carly, Drake and Josh and Zoey 101 have many crossovers, because of their shared universe, with the usual location for the cross over being the private school from Zoey 101. Nevel/Megan and Dustin/Carly are some popular crossover pairings.
 * It's worth noting that these three shows have crossed over in cannon. In the iCarly episode iStart a Fan War, Craig, Eric, Gavon, and Stacey all attended the iCarly fan panel.
 * Add Victorious to the list. Helen from Drake and Josh is the new principal at Hollywood Arts and there was the iParty With Victorious crossover with I Carly.
 * Camp Rock is a very popular crossover for Hannah Montana and Wizards of Waverly Place.
 * Inuyasha and Yu Yu Hakusho, seeing how they both deal with demons, and separation of worlds makes a good explanation of why youkai seemingly no longer exist in the modern era.
 * Warhammer 40000 and Neon Genesis Evangelion. Hell, Warhammer 40000 has probably been crossed over with pretty much everything by now.
 * Warhammer 40000 and Mass Effect do well together. Of note, is Hammerhand and Angels of the Storm
 * Though you wonder that there haven't been more 40k/DragonAge crossovers, what with the ridiculously similar magic system and the Qunari (who are Tau, but bigger and grey).
 * Tales of Vesperia and Blazblue. At least according to the author of the fanfic. Though it's in the Tales of section rather than the Crossover section.
 * Powerpuff Girls, Dexters Laboratory, and Samurai Jack happen in the same world, though this might just be a mythology gag by the creators. Almost all of the shows by Cartoon Network prior to Chowder and Flapjack might qualify with Fusion Fall.
 * Nickelodeon plays with this, having the major shows happen across different universes that seem to intersect.
 * Fan-video variant: A lot of people have made fanvids of Trigun to Firefly's theme song.
 * Heroes and Lost get crossed over a lot thanks to their overlapping fanbases and similar styles.
 * Supernatural and Lost get crossed over a lot for some unfathomable reason. Occasionally it's a Doppelganger Crossover due to Mark Pellegrino and Titus Welliver appearing in both, but that doesn't account for even half of the fic out there.
 * The Loads and Loads of Characters in Touhou Project means you can get a bunch of obvious crossovers. Or as some say: "Rule Circle 9: If it exists, there is a Touhou version of it".
 * Also, Rule P: If it exists, it has been "ponified" (that is, the characters are drawn as ponies from My Little Pony Friendship Is Magic)
 * The Buzz/Jessie ship from the Toy Story trilogy inspired a flood of fanart crossovers with the Space Western Firefly.
 * The Nightmare Before Christmas and Corpse Bride are often crossed over, for obvious reasons. Interestingly, the events of Nightmare will have happened, despite the fact that the events of Nightmare takes place in 1993, the year the movie came out, and Corpse Bride takes place somewhere in the Victorian Era.
 * In Tim Burton World, those two times are the same thing.
 * Digimon and Pokémon are incredibly common crossover stories, most of the time with each other, but crossovers with other series aren't uncommon.
 * Klonoa gets crossed over with Sonic the Hedgehog quite a lot. This is probably helped by (and possibly due to) the fact that Klonoa looks an awful lot like a Sonic character.
 * However, it doesn't measure up with how often Sonic the Hedgehog gets crossed over with Super Mario Bros. The fact that it happened in canon probably helps, but people were doing it for years beforehand.
 * Silent Hill is one popular resort town.
 * The Mortal Instruments series and Infernal Devices series don't have a huge crossover file yet, but it's steadily building. Considering the fact that Infernal Devices is really just a prequel and many characters are either ancestors of characters in Mortal Instruments or present in both series (such as Magnus Bane and various vampires), it's not surprising.
 * Star Trek/Star Wars crossovers are pretty common; not only are they the two biggest science fiction franchises, but nerds often write them as a side effect of arguments over which side's ships are more powerful.
 * Percy Jackson and The Olympians (and The Heroes of Olympus, naturally) as major crossover fuel with: Pokémon and The Kane Chronicles.
 * NCIS and Criminal Minds tend to get crossed over with each other a lot. It even shows with the NCIS crossover page and the Criminal Minds crossover page. (Press "Sort by popularity" on both pages to see what I mean.)
 * Even before the first season wrapped up, My Little Pony Friendship Is Magic had already been crossed over a ridiculous amount of times with Doctor Who. Of course, considering its already memetic status and the presence of background pony Doctor Whoof/Whooves, it isn't really that much of a surprise.
 * More strange is the constant crossover fanart with Portal 2, despite only sharing a very minor similarity in the role plays in both series.
 * Crossing Team Fortress 2 with Friendship Is Magic is very popular. Making subtle (and not-so-subtle) pony references is a popular pasttime on the official Team Fortress forums.
 * Entire Japanesse Humongous Mecha, including every Super Robot and Real Robot show can be in the next installment of professional example of this trope - Super Robot Wars.
 * Superhero genre in general can work like that - there is incredible amount of fanfictions and professional works crossing characters from Marvel Comics, DC Comics, Image Comics and others, that don't even bother with explaining how their worlds meet, just outright puts any superheroes they want into one world - Marvel Comics has even officially said that all of those crossovers with different company properties that imply they're taking place in one world are set on Crossover Earth where they really do coexist. Savage Dragon has also casually walked into crossovers with Hellboy (who is a frequent crossover target for anything dealing with similar themes - he has official crossovers with The Goon and Beasts of Burden) and Teenage Mutant Ninja Turtles.
 * The Doctor being an alien, time traveler, psychic, and cross-dimensional traveler with the preferred alias of "John Smith" makes Doctor Who hard to resist for Haruhi Suzumiya crossover fanfic writers.
 * Danny Phantom / Teen Titans crossovers are common amongst the fandom.
 * Crossovers between Code Geass and Mobile Suit Gundam 00 are also common..
 * Not to mention Code Geass and Death Note, mostly due to both shows having Villain Protagonists who are Magnificent Bastards.
 * Castle and Bones seem to be crossed over a fair bit. There's also more than a few crossovers with Firefly that tend to suggest some kind of connection between Richard Castle and Malcolm Reynolds (although the sheer amount of Actor Allusions Castle makes to Firefly help this along).
 * Fans of Puella Magi Madoka Magica tend to also like Ume Aoki's other works, Hidamari Sketch, which is more conventionally Moe. Considering what kind of story PMMM is, the adjoining of those two is widely disturbing.
 * Devil May Cry and Bayonetta might or might not be canonically in the same world, but as far as fan fiction is concerned, they are. Look for the villains and anti-heroes of every other Action Game the writer likes, but especially God of War and Darksiders.
 * For some reason, Sherlock and Good Omens Crossovers are quite popular. It could have something to do with the fact the most popular pairing of each fandom (Sherlock/John and Crowley/Aziraphale, respectively) have parallels, making them a rare case of cross-fandom Ship Mates. It also doesn't hurt that the two stories both take place in Britain.
 * Also in the vein of Sherlock Crossovers, WhoLock.
 * G1 My Little Pony and G1 Transformers are a common mash-up. The Movie was going to make this canon however they thought the plot was way too absurd.