Reality Warping Is Not a Toy

Reality warping is a cool power, isn't it? Definitely. But here is the catch. It can make your dreams come true, but not all dreams are good. So what happens when a Weak-Willed paranoid person becomes a Reality Warper? Things go Horribly Wrong pretty quickly - suddenly the monsters under your bed are real, your Imaginary Friend becomes an Imaginary Enemy, all Paranoia Fuel becomes real, and in the worst case scenario, you could end up in a Self-Inflicted Hell.

Even a strong-willed person will have trouble with winning this Superpower Lottery; Power Incontinence due to subconscious slips are no less likely for The Determinator with Heroic Willpower, and minor carelessness or forgetfulness can have disastrous consequences. Just how exactly do you practice Warping Reality without risking messing up the world you live in? Worse, reality warping doesn't necessarily provide a defense for consumption of drugs, Mind Control, or simple mental and emotional manipulation. Too bad you can't get ticketed for "Reality Warping Under The Influence".

Often used as a Fantastic Aesop on why only select people like God can have such power.

Anime and Manga

 * In Bleach the Hogyoku stretches the rules of probability to let its owner achieve his heart's desire. For Sousuke Aizen, the desire is power and for most of the series it works fine for him - he becomes The Juggernaut capable of curbstomping most of the remaining staff combined. The problem is, he associates humans (including shinigami) with weakness... while he is in control of the situation, he stays close to Bishonen Line. But once he meets his equal and suffers a Villainous Breakdown, the artifact dutifully fulfills his wish for more power, by "evolving" him into a full-blown Eldritch Abomination.
 * In Suzumiya Haruhi, Disappearance, Kyon's character development shows when
 * Although that instance was deliberate. The random changes Haruhi imposes on the world while filming a movie and losing track of the distinction between reality and fiction are a better example.
 * In Franken Fran, a bullied boy is given a treatment that allows his body to adapt to his thoughts, reforming according to his whims, but also instincts and self image. He is mostly happy with it, barring a short episode of Naughty Tentacles, but when he gets depressed... well, considering the rest of the chapters, he got let off easy, but still...
 * In A Certain Magical Index, the villain of the second arc has an apparently unbeatable Realitywarping power but is defeated by making him lose control of his fears, whereupon he accidentally makes the hero invincible and monstrous.
 * The entire plot of Pokémon 3 is a result of this trope and Living Dream. Unowns abduct Molly's dad. Molly wants dad back. Unowns turn dad into Entei and cover the estate in crystal. Chaos ensues.
 * In A Certain Magical Index, the villain of the second arc has an apparently unbeatable Realitywarping power but is defeated by making him lose control of his fears, whereupon he accidentally makes the hero invincible and monstrous.
 * The entire plot of Pokémon 3 is a result of this trope and Living Dream. Unowns abduct Molly's dad. Molly wants dad back. Unowns turn dad into Entei and cover the estate in crystal. Chaos ensues.
 * The entire plot of Pokémon 3 is a result of this trope and Living Dream. Unowns abduct Molly's dad. Molly wants dad back. Unowns turn dad into Entei and cover the estate in crystal. Chaos ensues.

Comic Books

 * In the Intercompany Crossover Batman Vs. The Incredible Hulk, The Joker gets the power to warp reality. Everything melts, buckles, and shifts...and then goes back to normal. It turns out that his mind was so unstable he couldn't wield or even hold on to the power for more than a few inconsequential minutes.
 * Aaand then, in Emperor Joker, it happens again. Except this time, it's Mr. Mxyzptlk's Reality Warper powers, which Joker could control with ease. Reality turns into bubblegum under Joker's thrall.
 * And even then he is defeated
 * This tended to be the focus of the stories with the original comic book series of The Mask.
 * In one Marvel comic, Beyonder rants about being Blessed with Suck. He is a literally omnipotent reality warper - his every thought defines reality around him. While it never directly works against him, it means he cannot really experience anything, since everything becomes what he expects - he literally lives his life surrounded by nothing but figments of his imagination.
 * In Thorgal - Jolan's Imaginary Friend Alinoe gets warped by his anger and not only turns against him but becomes The Virus.
 * The Tom Strong story "Tom Strong's Pal, Wally Willoughby" is about a pathetic nerd with unknowing reality warping powers whose rage and self-loathing nearly destroy a city.

Films -- Live-Action

 * The Krel from Forbidden Planet built a machine that could create whatever they wanted from the power of their own minds, but even so advanced and philanthropic a race weren't immune to the monsters from their ids.

Live-Action TV

 * Buffy the Vampire Slayer Anya's necklace allows her to do this in "The Wish" but it backfires and she loses her powers.
 * Red Dwarf, "Better Than Life": When the crew enter the Better Than Life video game, Rimmer's power to make things 'better than life' simply ends up sabotaging the game for all involved, as his subconscious won't let him be happy.
 * One episode of Star Trek: The Next Generation sees Enterprise blown all the away to the edge of the universe (a freak accident with an experimental engine upgrade). The laws of reality are pretty loose there, and so the crew spends most of the episode trying to avoid bringing their imaginations to life (which is a lot like trying not to think of pink elephants) while the technical crew tries to replicate the accident to send the ship back.
 * Another Star Trek example: in the Star Trek: The Original Series episode "The Squire of Gothos", Trelane is a godlike alien reality warper who creates new worlds to suit his whims. He torments the Enterprise crew with his powers, but just as he's about to kill Kirk, his parents show up and remonstrate him.
 * Cole in Charmed, when he was promoted to an avatar. He created a world where he was married to Phoebe, but she hated him, and to add injury to insult, he became Balthazar again, thus getting himself killed rather easily.
 * Tess in Roswell. She uses her powers to get a translation for the alien book and get the aliens home but they turn against her when they find out how she got the translation.

Literature

 * Both implied and applied (The last couple of pages of Blood of Amber, and the beginning of Sign of Chaos) in the Merlin cycle of Roger Zelazny's Chronicles of Amber, this is the reason that they don't take hallucinogenic drugs.
 * Well, actually, this is the reason nobody's taken hallucinogens more than once. Everybody's tried them - it's just that this also turns out to be the reason nobody bothers to mention the result to newcomers.
 * In one book of Chronicles of Narnia, the heroes' ship gets lost at sea. As they approach a mysterious island, they meet a lone survivor from a previous expedition, who warns them that this is the place where "dreams come true". Once they realize what exactly he means, they leave with all haste.
 * Ursula K. Le Guin's novel (and The Film of the Book) The Lathe of Heaven. George Orr's "effective dreams" cause him (and the rest of the world) a lot of problems, especially when his psychiatrist starts trying to use him to improve the world.
 * It's worth noting that The Lathe of Heaven was Le Guin's homage to/pastiche of Philip K. Dick.
 * Also from LeGuin, her Earthsea Trilogy wizards are capable of reality warping through use of the Old Speech and true names. However, since everything has a name, which it sometimes shares with other things, and assorted other elements of the cosmic balance, wizards are wary to actually use this power. One story of a wizard who wasn't ends up with him being condemned by the gods to shovel the salt he had accidentally extracted from the ocean (all of it)... and the gods, being the gods, keep him alive so that he can actually finish the job.
 * There was a short story describing a man in a psychiatric hospital, who developed reality-warping powers. He spends the story exploring his abilities, watching humanity and moving them like pawns. Until he squishes one pawn that wouldn't move... only to realize it was himself.
 * An alien species called the Assiti, whose "art" involves restructuring Quantum String fragments, are behind the relocation of Grantville, West Virginia in the year 2000 to Germany of the year 1632 in the 1632 novels. They didn't plan on moving a town backward through time... they were just being artistic and an inferior species got caught up. The Assiti are later exterminated to a man (to a being?) for being careless with their toys.
 * In a twist, the problem with their carelessness was not that the reality warping caused Bad Things to happen to them, but that other species got tired of warning them to cut it out and be a bit more responsible.
 * Pretty much the plot of the Michael Crichton book Sphere.
 * Labyrinths of Echo had the protagonist who have all his true wishes come true "sooner or later, one way or another"—Max survived only due to being too scatter-brained to concentrate on seriously willing anything and very afraid of dying. The magic with talent and will required, but control and understanding optional gives borderline cases. "Horror of Mages" happens when a powerful wizard is very afraid of a thing that doesn't exist—it may become real; bad news: such a phantasm can be destroyed only by its creator, who can't do it while afraid, and seeing one's personal nightmare approaching for real doesn't help. Mages with bad self-control sometimes have dreams reflecting into reality—so if one dreams of scorching a building, well, let's hope there was no one inside. The Echo's ex-Big Bad not only "demolished whatever offended his taste without leaving his bed", but had babies just appearing near his mistresses who wanted such a "souvenir" -- "Loyso's children" weren't normal humans.
 * The Eyes of Kid Midas has an Ordinary Middle School Student gain access to Reality Warping powers. It's all fun and games until he forgets himself and tells his rival to "Go to Hell." Then the Reality Bleed starts to set in. And it turns out to be Addictive Magic. And then he starts to lose control. And then he accidentally right before.
 * The central argument of Of Two Minds is over how much and how often reality warping can be safely used. The sequel takes this a step further, arguing that a society where everyone is free to reshape the world is ultimately boring and unsatisfying. That said, the heroine rejects this Aesop, arguing that there must be an alternative to the boredom of normal life.
 * In Chrestomanci Witch Week by Diana Wynne Jones, Charles enchants his hated classmate Simon so that everything he says is true, with some rather horrific results: he turns a girl's hand to gold and then temporarily makes it disappear altogether, and by saying "I'm not thinking of anything!", he makes himself mindless. It's pointed out that he's rather a silly person and it's pure luck that he hasn't said "Two and two are five" (or, come to that, "This pencil is a stick of dynamite" or "I don't exist".) Another classmate gets him to say "Nothing I say came true, and nothing I say will come true in the future", but this of course just inverts his reality-warping powers (and makes them less predictable). Eventually Charles is forced to admit both that it was wrong to cast such a spell, and that even if it weren't, Simon is the last person he would want to have that kind of power.
 * In the original Mistborn trilogy  and then in Hero of Ages  and right at the end of it all
 * In the Coldfire Trilogy, everyone on Erna is a Reality Warper thanks to the fae. In the time the books take place, humans have more or less figured out how to survive and even thrive with the fae though the fae's habit of making peoples' fears real means that Erna's level of technology has stagnated for 1000 years. In the backstory, this trope would have meant the end of the colonists who crashed on Erna—the only reason the humans survived was because

Tabletop Games

 * Subverted in Mage: The Ascension, of all places. The Marauders (the only faction prone to warp reality without explicitly meaning to) usually like what they get. Then again, they are all clinically insane. Played straight with the normal mages, though. Doing too much paradoxical magic results in the universe backlashing, which is not fun.

Videogames

 * Hemah in Fall From Heaven. His civilipedia description involves creating extremely dangerous monsters while dreaming.
 * In Heavy Rain, Norman Jayden's overuse of ARI (Added Reality Interface)
 * In the third First Encounter Assault Recon game, Alma is subjected to this. The Creep is one of her creations, yet she fears it more than anything else because

Webcomics

 * The Web Comics Minus ends with innocent little Minus . It's played for laughs, though, because Death Is a Slap on The Wrist.
 * A minor example in Misfile. A fortune teller in in a relationship that turns sour through a series of bizarre coincidences.
 * In 1/0, this occurs with both the author and the characters, which two of them hop from the author's given world into their dream worlds. This comes back to bite them when, since these characters can create anything they want, nothing's unexpected and it becomes boring, to which the author pulls them out of the dream.
 * In Endstone, apparently the discovery of the God of the Spire. Though he may have warped a Lotus Eater Machine.
 * There is a highly meta example in the Mega Crossover fancomic Roommates. The cast members are fictional characters their reality is their Canon and Fanon story and every single storyteller ever unknowingly warps it. If they mess up the result wont be pretty... Poor Morgan (Morgause/etc.) The Healer (LaFay/etc.) is more than bipolar by now.
 * In Gunnerkrigg Court Reality Warping is no fun at all for Zimmy. She has terrible Power Incontinence, and in fact can't control her powers even a little. Confusing hallucinations, hideously nightmarish monsters, and nonlinear time are just the start—she has her own personal Self-Inflicted Hell, a nightmare mirror of Burmingham, England inhabited by faceless "nobodies," where she can easily become trapped. Fans sometimes call it Zimmingham or Burminghell, but it's no laughing matter. The only things that even partly give her a break are rain, and the proximity of her psychic friend Gamma.

Web Originals

 * In-universe, this trope is why the SCP Foundation kills off most of the Reality Warpers it finds. Out-of-universe, it's to keep Mary Sues off the SCP lists.

Western Animation

 * A lighthearted example happens to Bat Mite in Batman the Brave And The Bold. Since he was living vicariously through Batman (tossing foes at him just to see him battle), Batman convinces him to cut the middle man out and do it himself. Problem is, his imagination started running away with him and he started fighting all of Batman's Rogues Gallery at once in a Dali-esque world. Batman basically had to talk him down / bail him out.
 * A Halloween episode of The Simpsons had the world living in fear of an omniscient Reality Warping Bart. Bart only wakes up screaming from the dream after his dream-self starts turning nice and hugs Homer.
 * In the Spider-Man: The Animated Series, Doctor Doom is anything but weak-willed. Yet when he tries to steal the Beyonder's power, his new utopia is soon assaulted by demons born out of his nightmares and subconscious fears. This is pretty much what happens in the original Secret Wars comic book too, which that ep was based on.
 * That happened with Cornelia's little sister in WITCH. She was being read to and unwittingly making the story come true, because as the Heart of Earth, she has Reality Warper powers. They end up convincing her to seal up her powers in a trio of regents until she grows up.
 * I Married a STRANGE Person!: After Grant Boyer is zapped by his TV satellite dish, he starts to warp reality to match whatever he imagines, and he just cannot stop imagining.