History Main / AlternateUniverseFic

** ''Fanfic/ACompleteTurnabout'' takes place in an AlternateUniverse where the DL-6 incident never happened, with the twist that the main character is Canon!Phoenix, trusted into Alternate!Phoenix' life for reasons yet to be revealed.

* ''Fanfic/EmpathTheLuckiestSmurf'' is a ''[[Franchise/TheSmurfs Smurfs]]'' fanfic series where (1) the Smurfs are all born through physical reproduction instead of through a DeliveryStork, (2) Papa Smurf had other fellow Smurfs in his generation as the parents of "his little Smurfs", but have all died during ThePlague, leaving the children as orphans, (3) the boy Smurflings were never de-aged adult Smurfs and Sassette was a real female Smurfling who was trapped in a CrystalPrison, and (4) [[PatchworkFic combines elements and characters from the]] [[ComicBook/TheSmurfs comic books]], [[WesternAnimation/TheSmurfs the cartoon show]], [[Film/TheSmurfs Sony Pictures' live-action film series]], ''WesternAnimation/SmurfsTheLostVillage'', ''ComicBook/JohanAndPeewit'', and [[MerchandiseDriven the [=PVC=] toy character line]].

* ''Fanfic/AbraxasHrodvitnon'', a ''Franchise/{{Godzilla}}'' Franchise/MonsterVerse fanfiction, is a {{Continuation}} type which began writing and publishing in 2019 as a sequel to ''Film/GodzillaKingOfTheMonsters2019'', and has evolved into more of AU with time and with the release of ''Film/GodzillaVsKong''. Major divergences from the [=MonsterVerse's=] canon post-''King of the Monsters'' include: San's decapitated head continues to regenerate Ghidorah instead of becoming an UndeadAbomination skull following the movie's events, the Titans remain awake in the aftermath of ''King of the Monsters''[='=] DawnOfAnEra instead of returning to hibernation, and a couple characters such as Ren Serizawa are more heroic.

** ''Fanfic/{{Daemorphing}}'' is a FusionFic with ''Literature/HisDarkMaterials''. It starts of as beat-for-beat retellings of the ''Animorphs'' books from different perspectives and with daemons, but it veers into NotHisSled territory when [[AscendedExtra Loren]] is introduced.

[[/folder]]

[[folder:Western Animation]]
* ''WesternAnimation/AdventureTime''
** ''Fanfic/AdventureTimeFrozenHearts'': This story is set before episode [[Recap/AdventureTimeS4E26TheLich "The Lich"]] with Simon and Betty having a different background.
** ''Fanfic/TheLastHuman'': The earlier chapters were written prior to the begining of the third season, so several things are quite different in this continuity. Among other things, Bubblegum was never aged back up, and Marceline originally looked human before she was vampirized.
* ''Franchise/AvatarTheLastAirbender:''
** [[WesternAnimation/AvatarTheLastAirbender The original series]]:
*** [[http://avatar.wikia.com/wiki/Fanon:A:TLAR A:TLAR]] is a full-on AU reboot of the ''WesternAnimation/AvatarTheLastAirbender'' storyline.
*** The fanfiction ''Fanfic/{{Embers}}'' by Creator/{{Vathara}}. Starting initially as a smaller one shot, it deals with what could have happened had Zuko and his Uncle had just slightly differing thoughts after the Siege of the North Pole, with an astounding amount of cultural and historical research put into this retelling.
** ''WesternAnimation/TheLegendOfKorra''
*** ''Fanfic/UnstableEquilibrium'' revolves around an alternate universe of where Asami falls for Korra, not Mako. Unfortunately, Asami has one major issue: she's also an Equalist. The story is ForWantOfANail fic where Hiroshi was the one that was killed by firebenders, not Yasuko.
* ''[[https://archiveofourown.org/works/10795119 Captain Underpants AU - He Didn't Leave Us]]'' is ExactlyWhatItSaysOnTheTin - an ''Literature/CaptainUnderpants'' AU where Mr. Krupp didn't lose his powers, and kept in touch with Harold and George as they grew up.
* ''Fanfic/TheRodSquad'' is ''WesternAnimation/ChipNDaleRescueRangers'' in TheSeventies instead of TheEighties. The whole story was extrapolated from [[http://rrdatabase.cdrrhq.ru/image/viewimage.php?image=1455 this fan art of Gadget in bell-bottoms]].
* The ''WesternAnimation/DannyPhantom'' Fanfic ''FanFic/AccidentMonthOne'' is pretty much another take on the universe with the same mechanics but different outcomes. It could be considered an AU reboot if you look at it that way.
* ''FanFic/PiratesVersusPrivates'' takes almost every ''Franchise/DisneyAnimatedCanon'' there is and smashes them together, though it focuses the most on the Sensational Six.
* ''Fanfic/TheWhiteMage'': An AU fanfiction of WesternAnimation/TheDragonPrince, which picks up after the canon ending of season three.
* [[https://www.fanfiction.net/u/4989417/lolzwaitwhat lolzwaitwhat]] ''An, Ann and Anny'' is an WesternAnimation/EdEddNEddy AU fic where [[RuleSixtyThree every member of the original cast is of the opposite sex]]. It was created by the author of ''Ed, Edd n Eddy Highschool'', who has also created several other Alternate Universes, like for instance, one where every character of the original cast (except Rolf) is an alien.
* ''WesternAnimation/TheFairlyOddParents'':
** ''FanFic/BurningBlack'''s entire premise rests on the idea that, six weeks after ''School's Out: The Musical'', [[WesternAnimation/TheFairlyOddparents Timmy Turner]] died falling from a jungle gym at school. The stories themselves take place four years after Timmy's death in a heavily affected Dimmsdale.
** ''Webcomic/HereByAccidentStayingOnPurpose'' is set in an AU where Timmy wrote about having fairy godparents as a child. Timmy and Trixie Tang weren't close friends but they'd sometimes dress up as a girl and a boy together. Years later, they reunite when Trixie visits Timmy's house. Timmy comes out as trans to her and the two start meeting more often.
** ''[[https://fairlyoddfanon.fandom.com/wiki/The_All_New_Fairly_OddParents! The All New Fairly OddParents!]]'' is a fanfic set in a world where Timmy has a twin sister, [[AscendedExtra Timantha]], who shares fairy godparents with her brother, among other things.
* [[http://www.annkniggendorf.de/gr/timeline.html AKK's]] "Raumjager" for ''[[WesternAnimation/AdventuresOfTheGalaxyRangers Galaxy Rangers]]'' uses a timeline where UsefulNotes/NaziGermany not only won, but has gone on to conquer the galaxy, and the normally persecuted Shane is now considered a paragon of the ubermenchen ideal... scarier when you remember that the writer is German herself. She also wrote "If Only," where Niko [[BeCarefulWhatYouWishFor wishes the tragedy that brought the Rangers together never happened]].
* ''[[https://www.fanfiction.net/s/4890669/1/Symphony_of_Angels Symphony of Angels]]'' is a ''WesternAnimation/{{Gargoyles}}'' fanfic where Demona DIDN'T betray Macbeth in 1057 A.D, but [[InSpiteOfANail things went south anyway]].
* ''WesternAnimation/GravityFalls'' has inspired a number of these, some of which have become popular enough to achieve FanVerse status:
** ''Fanfic/TranscendenceAU'' is a ''WesternAnimation/GravityFalls'' fanfic that spiraled out of control, based on an event where Dipper fused with Bill's demonic energy and the barriers keeping the weird stuff in [[EldritchLocation Gravity Falls]] all came down. [[FantasyKitchenSink Now the whole world's like that.]]
** ''[[Fanfic/ReverseFallsAU Reverse Falls]]'' is an AU where Lil' Gideon and Pacifica Southeast are the heroes, with Dipper and Mabel as a pair of CreepyTwins antagonists
** ''Monster Falls'' sees the citizens of Gravity Falls being turned into assorted monsters from folklore and mythology, usually featuring Dipper as a [[OurCentaursAreDifferent deer-centaur]], Mabel as a mermaid, Grunkle Stan as a gargoyle, Soos as a clay homunculus, Wendy as a werewolf, and so on.
** ''[[https://www.wattpad.com/story/62176307-gravity-rises-au Gravity Rises]]'' swaps most of the personalities and roles of the characters within pairs. Mabel becomes the curious, scientific one (Pine Tree), while Dipper takes on the role of the happy-go-lucky twin (Shooting Star). The two fight against the psychic Pacifica Gleeful (or Pleasure, depending on the version) and rich jerk Gideon Northwest.
** ''[[http://relativityfalls.tumblr.com/ Relativity Falls]]'' swaps the ages and roles of the main cast around: here, young Stanley and Stanford Pines are spending the summer in Gravity Falls with their "Grauntie" Mabel, investigating the supernatural with Maria Ramirez (a young version of Soos' Abuelita) and a teenage version of "Manly Dan" Corduroy. Later, [[spoiler:Dipper is revealed as this universe’s Author.]]
** ''[[http://sailorleo.tumblr.com/tagged/reunion-falls Reunion Falls]]'' revolves around Dipper and Mabel being separated at birth, and the adventure that ensues when Mabel heads up to Gravity Falls to reunite with Dipper. It also features the Mystery Twins as transgender (Mabel was assigned male at birth and Dipper was assigned female at birth), an increased role in the story for Mabel's friends Candy and Grenda, and Mabel x Pacifica as a couple.
** ''[[http://gravity-key.tumblr.com/ Gravity Key]]'' transplants the action of the show from the Pacific Northwest to [[OnlyInFlorida the Florida Keys]].
** ''Fight Falls'' is a darkly-humorous AU where Dipper and Mabel are a pair of scrappy, hot-headed delinquents who beat the crap out of any monster who threatens them or their friends.
** ''Human Journals'' features the three Journals [[spoiler:written by Stanford Pines]] as human (or, at least, humanoid) brothers named Eins, Zwei, and Drei, who either became the Journals by magic or had their contents tattooed onto them by the Author.
** ''The Author of the Journals, Stanley Pines'' is an AU where [[spoiler:Stan is the Author of the Journals instead of his twin, Ford. In the fic, Ford is able to go to West Coast Tech, but he dies in a plane crash. Regret and grief drive Stan to go to Backupsmore University and eventually, he and his girlfriend Carla go to Gravity Falls and he creates the Journals. But it’s also clear that things aren’t as they appear to be…]]
** ''Anti Gravity'' swaps the ages of characters much like ''Relativity Falls'', but this time Wendy and Soos are twelve, Dipper, Mabel, and Pacifica are fifteen, and Stan is the same.
** ''[[https://twitter.com/Chillguydraws/status/1065244673923579905 Thicc Falls]]'' initially started as a simple joke about adult!Pacifica (here having the nickname "[[HartmanHips Thicc]][[SheIsAllGrownUp ifica]]") having wide hips, before being developed into an au featuring aged up versions of the other character with similar over-developed bodies. Such as Dipper (nicknamed "[[GagPenis Big]] [[{{Hunk}} Dipper]]"), Mabel (nicknamed "[[GagBoobs Ma]][[BuxomIsBetter boobs]]"), Wendy ("Chill Corduroy"), Grenda ("[[AmazonianBeauty Giant Grenda]]") and Candy ("Kawaii Kandy") as well. He not only later made designs for the [[https://twitter.com/chillguydraws/status/1065436023142916096 Reverse Falls AU]] as well, but later expanded into it's own universe (appropriately called the ''Thicc-Verse'') with shows like [[https://www.newgrounds.com/art/view/chillguydraws/thicc-verse-adventures Adventure Time]], [[https://twitter.com/Chillguydraws/status/1065338353627869187 Steven Universe]], [[https://twitter.com/chillguydraws/status/1065293322053459969 The Loud House]],[[https://twitter.com/chillguydraws/status/1065270754282037254 Star Vs. The Forces Of Evil]] and [[https://twitter.com/search?q=thicc-verse%20ok%20ko&src=typd OK KO]]. Booru [[https://thiccversebeyond.booru.org/index.php?page=post&s=list here]] (Warning: [=NSFW=])
* ''WesternAnimation/InfinityTrain''
** ''Fanfic/DownAndOut'': By nature of Simon still being alive, thanks to Grace being able to save him a second time.
** ''Fanfic/InfinityTrainFanfic'': Because it is the first fic ever written for the series, being written in the almost three year gap between the pilot's release in November 2016 and the show's premiere in August 2019, the entire nature of the train and the meaning of the numbers is different than in canon.
** ''[[https://archiveofourown.org/works/27260902/chapters/66598906 Welcome to Infinity]]'' takes place in a world where the train doesn't exist. All the show's characters live in the small town of Infinity, Wisconsin (Lake is Tulip's twin, Amelia is a teacher, etc.) and have to come to grips with their {{fatal flaw}}s the old-fashioned way.
* ''WesternAnimation/InvaderZim'':
** ''[[https://www.fanfiction.net/s/9417725/1/Until-the-Rain Until the Rain]]'' is a fanfic set in a world where Zim is a bullied smeet who fled to Earth and was found and adopted by an adult Dib. Also, both GIR and Minimoose were created by Professor Membrane, who died some time prior to the story, and Dib is on better terms with his old classmates.
** ''[[https://www.fanfiction.net/s/12566653/1/The-Discount-Smeet The Discount Smeet]]'' is an AU where an adult Dib becomes a space traveller and buys Zim from an intergalactic market, eventually coming to see the smeet as his own child.
* ''WesternAnimation/JackieChanAdventures'':
** ''[[Fanfic/{{TheUltimateEvil}} The Ultimate/Stronger Evil]]'', a duology set during the first two seasons (''The Ultimate Evil'') and later covering events which occurred during the show's fourth and fifth seasons (''The Stronger Evil''); in which OriginalCharacter Valerie Payne begins working for the Chans, and catches the [[VillainousCrush attention]] of [[VillainProtagonist Shendu]] who discovers she is his [[BalanceBetweenGoodAndEvil cosmological]] [[WonderTwinPowers Other]] which can enable him to gain unlimited power.
** ''Fanfic/QueenOfAllOni'', in which Daolon Wong's spell at the start of Season 4 restores Jade's [[SuperPoweredEvilSide Shadowkhan Queen alter-ego]] instead of awakening Tarakudo.
* ''Fanfic/DeceptionUnveiled'' is an AU that diverges from ''WesternAnimation/{{Jem}}'' during "Glitter and Gold". Jerrica decides to tell her boyfriend Rio that she's Jem.
* A few ''WesternAnimation/TheLoudHouse'' fanfics of this nature exist:
** [[https://www.fanfiction.net/u/6046326/ Mitchell Movie Productions]] is creating a Fanfic Multiverse where we see the lives of different Loud Kids from alternate realities:
*** [[https://www.fanfiction.net/s/13546996/1/ Citadel of Loris]] focuses on a interdimensional citadel full of Lori Clones going about their daily business and forming friendships with their newfound lives as Lori clones.
*** [[https://www.fanfiction.net/s/13574783/1/Loud-Verse-The-Luna-House The Luna House]] Shows an alternate reality where Luna, an only child in this fic, is split into Multiple Lunas with different personalities.
** Their are fics which explore the (now debunked) fan theory involving Lincoln being secretly adopted, such as ''Thicker Than Blood'', [[spoiler: which also included Lincoln having a long-lost twin sister, based on his rule 63 counterpart Linka]].
*** ''Fanfic/FindingALoud'' played with the idea by, instead of having Lincoln unknowingly adopted by when he was an infant, having him meet the Loud family and get adopted by them about a year before the canon time period. [[spoiler: And curiously also giving him a twin sister.]]
** "Ageswap" universes (where ages and birth orders of the Loud siblings been swapped around) are common: ''[[https://www.fanfiction.net/s/12109012/1/Loud-House-A-Family-Together Loud House: A Family Together]]'' is one where Lincoln is the eldest Loud sibling at age 20 who ran away from home and went missing for 9 years before finally returning. Another is ''[[https://www.fanfiction.net/s/12227705/1/Flip-the-Lid Flip the Lid]]'', in which Lincoln finds himself in a world where the birth order of his sisters is reversed.
** And of course, universes where [[Rule63 the Loud sisters are instead the Loud brothers]] are also extremely common. Ones where Lincoln is a girl named Linka are more popular. The fact that theirs a ''canon'' episode where Lincoln [[spoiler: [[AllJustADream in his dreams]]]] visits a universe where his sister are gender swapped [[spoiler: and briefly a universe where he's gender swapped too]] probably helped [[FanFicFuel fuel these kinds of fic]].
** Due to the series mainly taking place in 2016 (and all its trappings), many {{Period Fic}}s have been made. The most popular ones being set from the 1930s to the 1990s.
** Fics where the Loud siblings are not related are also popular, due to removing the {{Squick}} factor that [[BrotherSisterIncest Loudcest]] fics usually have.
** Fanfics that turn the Loud siblings into superheroes, like ''Fanfic/{{Archetypal}}'', are also pretty common.
* ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' has quite a few examples:
** [[FanFic/RainbowDoubleDashsLunaverse The Lunaverse]] is a SharedUniverse of [[WesternAnimation/MyLittlePonyFriendshipIsMagic MLP:FiM]] fanfics, where Princess Celestia became evil instead of Luna, with a new set of main characters based on background and side characters while the original main cast is flipped into minor roles.
** [[FanFic/RainboomsAndRoyalty The Dashverse]] is based on the simple premise that rather than being in Canterlot on the day that the [[WesternAnimation/MyLittlePonyFriendshipIsMagic Mane Six]] got their cutie marks, Princess Celestia was instead in Cloudsdale, and ended up taking on Rainbow Dash as her student instead of Twilight Sparkle.
** ''FanFic/NightsFavoredChild'' diverges from [[WesternAnimation/MyLittlePonyFriendshipIsMagic canon]] during the battle between Celestia and Nightmare Moon a thousand years ago. In this fic's universe, Nightmare Moon won, brought about [[TheNightThatNeverEnds eternal night]] (and found a way to avert the [[TheEndOfTheWorldAsWeKnowIt negative]] aspects of it), [[WrittenByTheWinners erased Celestia from the history books]], and turned Equestria into her personal [[TheEmpire empire]].
** ''FanFic/ThePowersOfHarmony'' is a ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' story that borders on being an outright AlternateContinuity -- aside from the Mane Cast having met and befriended Zecora, ''everything'' after the series pilot is ignored in favor of the story's timeline and take on events. That said, elements of canon (characters, backstories, events) are incorporated or alluded to when necessary.
** ''Fanfic/LifeInManehattan'' is another MLP AU fic. This one diverges from canon when the Elements of Harmony are discovered some time before the pilot by Honey Do [[spoiler: aka Daring Do]] and moved to a museum in Manehattan. Because of that, Celestia chooses that city for the Summer Sun Celebration, and it is there that Twilight goes and befriends different ponies to be the bearers of the Elements.
** ''Fanfic/{{Chains}}'' is an MLP AU that actually plays very similar to the MLP canon, but with one major twist that the fanfic has centered around; humans exist and were made a SlaveRace by the Equestrians.
** The ''Webcomic/JuniorGala'' series created by ''Website/DeviantArt'' users, Kaemantis and Bizerbit is set in an AlternateUniverse. Some of the changes made in the JG 'verse consist of [[AgeLift character ages,]] [[WhatIf certain]] [[AlternateHistory events,]] etc.
** Lunaverse alum [=GrassAndClouds2=] has started his own AU SharedUniverse of MLP fics, Fanfic/TheCadanceverse. The premise of this one is that ''both'' Celestia and Luna were corrupted, forcing Cadance [[spoiler: (a {{golem}} created to serve as their intermediary)]] to use the Elements of Harmony to seal them both away, before taking over Equestria herself.
** Warren Hutch (author of ''Fanfic/{{Windfall}}'' and ''Fanfic/EarthAndSky'') wrote ''Fanfic/TheWhiteMare'', which takes place in an Equestria where Princess Celestia went into self-imposed exile after banishing Nightmare Moon. She subsequently became ShroudedInMyth, her only real friend a certain yellow-and-pink pegasus... This means that, among other things, modern Equestria is a republic, there is no Ponyville[[note]]Because it was build around Sweet Apple Acres, which was granted to Granny Smith's parents by Princess Celestia[[/note]], and the Mane Six are different in many ways (Fluttershy is more assertive, Rarity is a gem prospector, and Applejack is a travelling seed-and-flower salespony with a Manehattan accent) though ultimately recognizable as themselves.
** ''Fanfic/ThisPlatinumCrown'' is a notable example, with [[DarkerAndEdgier somewhat darker]] reimaginings of episodes, badass [[BattleCouple battle couples]], while keeping the main themes of the show, while keeping the main theme of the show- Friendship is Magic.
** ''FanFic/HarmonysWarriors'' is a contextual reassignment CrossOver fanfic of the ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' Universe to make it more resemble the Franchise/MarvelCinematicUniverse. It's rather expansive, clocking in at five full-length stories (three of which are still in progress), and [[AllThereInTheManual two anthologies]], with even more planned.
** ''[[Fanfic/TheRockFarmersDaughters The Rock Farmer's Daughters]]'' takes place in a universe where Pinkie missed the Rainboom (and a different mare is the Element of Laughter, though it's never mentioned), its main focus being how it'd affect Cheese Sandwich and his destiny, ultimately leading to him working on the Pie Rock Farm and getting to know the Pie Family.
** ''[[FanFic/StallionsofHarmonyVerse Stallions of Harmony Verse]]'' re-imagines the pilot where Blueblood and Shining Armor were both sent to Ponyville instead of Twilight for the Summer Sun Celebration.
** ''[[https://www.fimfiction.net/story/230072/twilight-sparkle-of-the-royal-guard Twilight Sparkle of the Royal Guard]]'' is an AU where Shining Armor encourages Twilight to join the Royal Guard.
** ''Fanfic/EquestriaDivided'' is, ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' [[JustForFun/XMeetsY meets]] ''Series/GameOfThrones:'' [[RecycledInSpace the strategy game]]
** ''FanFic/TheStoryOfTwilightGlow'': Twilight Sparkle was instead born an Earth Pony. As a result, Moondancer became the Element of Harmony, and she fails to stop Nightmare Moon, allowing her to take power.
** ''Fanfic/{{Greenfire}}'': A universe where Spike was never hatched by Twilight, instead growing up alone in the Everfree Forest. Oh, his name is Greenfire, as well.
* ''[[https://www.fanfiction.net/s/12815765/1/This-is-Home-Just-a-Typical-Morning This Is Home]]'' and its sequel ''[[https://www.fanfiction.net/s/12816165/1/This-is-Home-The-Ties-That-Bind The Ties That Bind]]'' are two ''{{Franchise/Nicktoons}}'' fics where many of the Nicktoons characters live together at a foster house, with human versions of Cosmo and Wanda being the parents.
* ''Fanfic/CatRa'' is a ''WesternAnimation/SheRaAndThePrincessesOfPower'' fanfic where Catra discovers the sword and becomes She-Ra, joining the Rebellion while Adora remains with the Horde.
* ''WesternAnimation/TheSimpsons''
** [[http://www.fanfiction.net/s/8452944/1/The-Thompsons The Thompsons]] has the idea of "What if Homer and Marge were not the parents of Bart, Lisa and Maggie?"
** ''FanFic/LisaFitzgerald'' is set in a world where Lisa is not the daughter of Homer and Marge.
* ''WesternAnimation/StarVsTheForcesOfEvil''
** ''Fanfic/TheEarthAdventuresOfMonStar'' is set in a scenario where Toffee is Star's father instead of River and Marco is Star's betrothed instead of just her friend and potential love interest.
** ''Fanfic/TheRoyalProtector'' has Star sent to [[BoardingSchoolOfHorrors St. Olga's]] instead of being sent to Earth, developing a SplitPersonality due to the abuse and brainwashing at the boarding school, and escaping two years later during an assassination attempt by Toffee's minions. Meanwhile, Marco became close friends with Janna and Oscar, as he was assigned to be a student mentor to them instead. Star and Marco end up meeting due to the former using a SummonEverymanHero spell to save herself from the aforementioned assassins.
** ''Fanfic/JannaVsTheForcesOfEvil'' has the Magic Book of Spells come to Earth by itself, with Star having mysteriously disappeared when Toffee (inhabiting Ludo's body) took control of Mewni. Janna finds the book in a dumpster and learns how to wield actual magic, quickly proving to have a natural talent for it. She and Marco start hanging out because he's worried about such a powerful tome being in the hands of [[NightmareFetishist Janna of all people]], but they soon become best friends who find themselves dragged into the ongoing conflict against Toffee and the search for Star.
* ''WesternAnimation/StevenUniverse'' has a few:
** ''Fanfic/OpalSapphireRubyAndSteven'' takes place in a universe where Opal [[spoiler: is the permafusion]] instead of [[spoiler: Garnet]].
** Both ''[[http://archiveofourown.org/works/3810709/chapters/8492101 Connie Parallel]]'' and ''[[http://archiveofourown.org/works/3743083/chapters/8299711 Buck Dewniverse]]'' are stories where Steven ISN'T the human-Gem hybrid.
** A common theme is the "FanFic/MomswapAU", where Steven is being raised by the Homeworld Gems (specifically Lapis, Peridot, and Jasper) instead of the Crystal Gems. [[http://momswapverse.tumblr.com/tagged/fake_cartoon_reviews/chrono Here]] is one of the better ones.
** ''[[https://archiveofourown.org/works/14605911/chapters/33758472 Revelations]]'' revolves around Steven admitting that he isn't Rose Quartz at the trial, and the consequences.
** ''[[https://tapas.io/series/subsides Steven Universe B-Sides]]'' is a variant on Momswap where Bismuth, Lapis Lazuli, and Peridot are the main members of the Crystal Gems.
** ''[[https://gemcrust.fandom.com/wiki/The_Diamond_Alternate_Universe The Diamond AU]]'' is a version where the Diamond Authority were always equal in terms of power, however this had the side effect of making Pink the TokenEvilTeammate due to lacking the CharacterDevelopment she had in the original universe.
** Several fics take place in an AU where Rose Quartz and Pink Diamond are separate people (passive-aggressively termed "[[DepartmentOfRedundancyDepartment Rose Quartz is Rose Quartz]]"). ''[[https://archiveofourown.org/works/18007175 The Darkness Between Stars]]'' and ''VideoGame/FlawedCrystals'' are two of the more notable ones, and use this divergence as a springboard for DeconstructionFic.
** ''Fanfic/StevenUniverseAlternateFuture'' serves as an [[ExactlyWhatItSaysOnTheTin AU rewrite]] of ''WesternAnimation/StevenUniverseFuture'' that mixes WhatCouldHaveBeen with AuthorAppeal to make a story the author compares to ''Film/ZackSnydersJusticeLeague''.
* For ''WesternAnimation/TeenTitans'', "''[[http://www.fanfiction.net/s/6478556/1/Northern_Star Northern Star]]''" and "''[[http://www.fanfiction.net/s/7401598/1/Apprentice Apprentice]]''" are two examples of the Apprentice AU theme that is popular amongst TT fanfiction - the idea of "What if Robin had stayed as Slade's apprentice?"
** ''FanFic/JewelOfDarkness'', fic that is built on the premise that Raven was banished from Azarath when her powers first awakened as child, rather than later in her life. She is then found on the streets by Slade, who raises her as his child and apprentice.
* While primarily set in the universe of ''WesternAnimation/TeenageMutantNinjaTurtles2012'', ''FanFic/TeenageMutantNinjaTurtlesVengeanceOfTheFootClan'' and its sequels also incorporate characters from other incarnations of the ''TMNT'' franchise, such as Kitsune from [[ComicBook/TeenageMutantNinjaTurtlesIDW the IDW Publishing comics]], Max Winters from [[WesternAnimation/{{TMNT}} the 2012 film]], and Eric Sacks from [[Film/TeenageMutantNinjaTurtles2014 the 2014 film]].
* ''Fanfic/TalesFromTheOtherRailway'' is one for ''WesternAnimation/ThomasAndFriends''.
* ''WesternAnimation/TotalDrama'' has a few.
** ''Fanfic/BigBrotherBlues'': In this story, Alejandro never gets singed by the volcano and thrown into a robot suit for two years, and [[spoiler:participates on ''The Ridonculous Race'' with his sister.]]
** ''Fanfic/CastSwap'' explores how the series would be different if the ''Pahkitew Island'' contestants instead debuted in ''Revenge of the Island'' and vice versa.
** ''Fanfic/ChangeOfPlans'': Instead of flirting with Tyler in "The Ex-Files", Courtney decides the better move is flirting with Cody. Things only branch off more from there.
** ''Fanfic/ACodetteWorldTour'': In this story's universe, Bridgette and Geoff's relationship never recovered after Geoff started becoming a jerk on ''Action'', resulting in their breakup before ''Total Drama World Tour''. The team rosters are also different due to [[ForWantOfANail a couple of small changes in the setup]].
** ''Fanfic/CourtneysCrusadeForRedemption'': As the description says, Courtney travels back to her younger ''All-Stars'' body to compete again and try to SetRightWhatOnceWentWrong.
** ''Fanfic/TheDoctorWillSeeYouNow'': As the summary says, this story branches off from the official continuity of ''Total Drama World Tour'' after the episode “I See London…” Everything that happened in that episode and before in the season still occurred, but there are subtle differences between this story and the official canon in certain areas moving beyond it. Courtney isn’t instantly suspicious of Gwen attempting to take Duncan from her. Gwen attempts to (weakly) defend her actions in her confessional where she expresses guilt over betraying Courtney’s trust. And the Goth attempts to end the budding relationship with Duncan until the season is over and he officially breaks up with Courtney.
** In ''Fanfic/FromSurfboardsToDiapers'', the events of ''Action'' and ''World Tour'' never occur, so the 22 contestants all return to their ordinary lives after ''Island'' ends (well, most of them do; Bridgette, [[TeenPregnancy not so much]]).
** ''Fanfic/KingdomHeartsCodysStory'': ''Total Drama World Tour'' never occurs in this story's continuity, and instead, the 22 contestants leave ''Total Drama'' behind for good following the end of ''Total Drama Action''.
** ''Fanfic/LegacyTotalDrama'' answers the question of how ''Total Drama'' and the lives of its contestants would have turned out if Gwen was killed by the serial killer in "Hook, Line, and Screamer".
** ''Fanfic/TheLegendOfTotalDramaIsland'': The story is a reimagining of ''WesternAnimation/TotalDrama's'' first season, so perforce none of the show's canon events are directly acknowledged.
** ''Fanfic/LoveAintEasyItsEzzy'': This fic gives us an idea of what might have happened if nothing came of Courtney's gripes about not being in the second season and how far Justin's manipulations could take him in the show without Courtney suing her way on.
** ''Fanfic/MonsterChronicles'': This series is story branches off from both ''Total Drama World Tour'' and ''Total Drama All-Stars''. In ''Total Drama World Tour'' in this story's universe, Duncan and Gwen kissing behind Courtney back has unexpected consequences when a supernatural serial killer, [[NamesToRunAwayFromReallyFast Cedric von Túfeice]] [[spoiler:takes over Cody's body]]. Now the contestants are now in more danger than ever before, with a serial killer joining the game and threatening their lives. In ''Total Drama All-Stars'' in this story's universe, ''Total Drama All-Stars'' take place two years after ''Total Drama World Tour''. 16 more contestants have been added and they are now competing for a prize of 1 billion dollars. Other changes from the events caused by the previous story are shown with Duncan and Gwen broken up, but deciding to remind friends, Cody and Duncan becoming friends, Lindsay not being in this season because of her having a baby with Tyler, and Mal being more dangerous because of his connection to [[NamesToRunAwayFromReallyFast Cedric von Túfeice]]
** ''Fanfic/RandomDramaSeries'': The series is what the canon series could've been like if everyone's debut season was switched around as well as adding a few {{Original Character}}s.
** ''Fanfic/SecondChanceAtLove'': Unique for the author’s stories, this one takes place in an alternate continuity from the show. Mostly this is shown in the events of ''World Tour'', but many of the bits referring to ''Action'' also tell of different events. The biggest changes to the overall seasons are Harold beating Duncan at the finale of ''Action'', and Heather winning after beating Alejandro during ''World Tour''’s finale. The greater differences lie in which couples formed in this version of events. Outside of Gwen/Duncan (which is ended by the story’s end), none of the official canon couples are present. By the time the story begins, the couples are: Harold/Heather, Tyler/Eva, Noah/Bridgette, Geoff/Izzy, DJ/Courtney, Justin/Katie, Owen/Sadie, Ezekiel/Beth, and the LoveTriangle of Lindsay/Cody/Leshawna. By the end of the story, its implied Gwen will hook up with Trent.
** ''Fanfic/ATDALoveTriangleWithBettyCodyAndGwenny'': Basically showing how Season 2 would be if Geoff's corruption wasn't stopped; the story also focuses on the off-screen action, with the characters that didn't compete or were eliminated already.
** ''Fanfic/ThreeTestsOfValor'': A story set during the 'Island' season, with Lindsay and Harold falling in love with each other instead of with Tyler and Leshawna, respectively.
** ''Fanfic/TotalDramaActionAllIn'': In this fic's continuity, events during the first season special result in all 22 contestants having to participate in the second season rather just 14 (later 15) of them.
** ''Fanfic/TotalDramaAllMixedUpIsland'': Like other fics, the cast is swapped into different seasons.
** ''Fanfic/TotalDramaBigBangTheory'': Imagine the cast of the Total Drama series in the world of The Big Bang Theory. That's pretty much what this fanfic is about.
** ''Fanfic/TotalDramaCodysRedemption'': The description says it all. Cody travels back to his sixteen-year-old body and competes for a second time on ''Total Drama Island''. Because of his knowledge of the whole season, he’ll be changing things up from what originally happened into a new timeline.
** ''Fanfic/TotalDramaRedemption'': Noah finds himself transported to an alternate timeline where he is given the opportunity to redeem himself for his actions. At first the differences are subtle, but by the time of ''World Tour'', they're massive.
** ''Fanfic/TotalDramaRedux52'': What if the Island, Revenge of the Island, and Pahkitew contestants competed on the first season.
** ''Fanfic/TotalDramaWhatIfSeries'': The ''Revenge Of The Island'' and ''Pahkitew Island'' cast are switched to the first season.
** ''Fanfic/TotalShuffledIslandSeries'' The series is what the canon series could've been like if everyone's debut season was switched around.
** ''Fanfic/TotalDramaUnderdogs'' demonstrates how ''Island'' might have been like if Ezekiel never said his sexist comments out loud and thus did not become the first eliminated on the show.
** ''Fanfic/TwinningWithATwist'': The fic is essentially a retelling of ''Pahkitew Island'', but Sammy and Amy are on opposing teams. It makes a bigger difference than one might think. For example, as opposed to Jasmine being her OnlyFriend as in canon, Sammy now also finds support in Ella, Sky, Beardo, and Shawn ([[IWorkAlone sort of]], though he's coming around).
** ''Fanfic/UnbreakableRedSilkenThread'' In this story, Total Drama ended after the third season. Cody and Heather go to the same high school. After a few months they start a relationship. When they graduated from high school, they go to college where they meet people who were in Total Drama: Revenge Of The Island and Total Drama Pahkitew Island in canon, as well as Kitty and Emma from Total Drama Presents: The Ridonculous Race showing up later.
* ''Franchise/{{Transformers}}''
** ''[[http://www.fanfiction.net/s/4819959/1/Odd_Couple Odd Couple]]'', for ''WesternAnimation/TransformersAnimated''. It originally centered around Prowl and Lockdown, but eventually became so fleshed out that an entire other story set called [[http://www.fanfiction.net/s/5025371 Odd Moments]] was put up to show peeks into everyone else's stories.
** ''[[https://www.fanfiction.net/s/9745034/1/Suddenly Suddenly]]'' is a ''WesternAnimation/TransformersPrime'' fanfic set in the ComicBook/TransformersShatteredGlass MirrorUniverse. In addition to the morality swap, Jasper is a dictatorship run by the Autobots; Sierra is the third member of the human trio (Raf doesn't show up until much later); Miko is deaf and speaks via sign-language; and the biggest change of all is that June is adopted by the Decepticons when she is a kindergartner, so Jack is raised as a Decepticon.
** ''Fanfic/AChildShallLeadThemTransformers'' revolves around Swoop gaining the Matrix of Leadership via an accident and becoming Pterodactus Prime, the new leader of the Autobots.
** ''[[https://www.fanfiction.net/s/8826179/1/Domestic-Electronics Domestic Electronics]]'' is set in a world where ''Franchise/{{Transformers}}'' are tiny man-made (but still sentient) robots that turn into personal electronics, small appliances, etc, as opposed to giant sentient robots from another world.
** ''[[https://www.fanfiction.net/s/7430603/1/Swarm Swarm]]'' is a ''WesternAnimation/TransformersAnimated'' fanfic where Wasp is a hornet and Bumblebee is (ironically) a honeybee who - despite being male - is capable of becoming a queen [[EggLayingMale and laying eggs]].
** The ''[[https://archiveofourown.org/series/1424047 Primacy (yelling all the way down)]]'' series is set in a world where [[WesternAnimation/TransformersPrime Ratchet]] was chosen to be the new Prime instead of Orion.
** The ''[[https://archiveofourown.org/series/1955971 Cassetticon Hot Rod]]'' series is ExactlyWhatItSaysOnTheTin - a series set in a world where Hot Rod is a Cassetticon.
** The ''[[https://archiveofourown.org/series/1110879 you want the world/well what's it worth?]]'' series is set in a world in which the majority of the bots are both human females and involved in the American political scene.
** The ''[[https://archiveofourown.org/series/1941025 TF Equestrian AU]]'' series is ExactlyWhatItSaysOnTheTin - a series where several of the characters are either riders or horses.
** The ''[[https://archiveofourown.org/series/1189521 Decepticon Hot Rod AU]]'' is a series set in a world where Hot Rod became a Decepticon in "Autocracy".
** ''[[https://archiveofourown.org/works/16508525/chapters/38666408 Alike In Indignity]]'' is set in a world where Starscream is an Autobot who falls in love with Megatron.
** ''[[https://archiveofourown.org/series/1135949 Metal: Cybertron's Rock and Roll]]'' is set in a world where the war is nonexistent and the Autobots and Decepticons are rock bands.
** ''[[https://archiveofourown.org/works/34664242/chapters/86302408 Dancing Around the Pole]]'' is a ''WesternAnimation/TransformersAnimated'' fanfic where Optimus became a stripper after getting kicked out of the Elite Guard Academy.
* ''Fanfic/VoltronDuality'' is a WesternAnimation/VoltronLegendaryDefender AU where Matt was the one to crash land on Earth instead of Shiro.
* The ''[[https://princepeepers.tumblr.com/ Prince Peepers]]'' AU is exactly that - a WesternAnimation/WanderOverYonder AU where Peepers is the prince of the first planet Lord Hater tries to conquer, and [[AltarDiplomacy marries Hater]] so that the latter can claim the former's planet for his own.
* From ''WesternAnimation/YoungJustice'', written during the hiatus, ''Fanfic/YoungJusticeDarknessFalls'', which starts the hour after the 2nd season ends, and makes a major divergence compared to how canon ended up due to lack of foresight.
** Similarly, ''Fanfic/YoungJusticeTitans'', which brings the Young Justice spin on the mystic to the forefront with the ArcVillain this season being Trigon The Terrible.

[[folder:Video Games]]
* ''Franchise/SuperMarioBros'':
** The infamous ''VideoGame/HammerBrother'' takes place in a ''Mario'' AU set on Earth.
** The ''Super Mario Bros'' ''Fanfic/MyPainMyThrill'' is an AU where Bowser and Peach were once in a SecretRelationship that resulted in Bowser Jr. Bowser is also the Koopalings' uncle instead of either being their father or being completely unrelated.
* ''Franchise/{{Pokemon}}'':
** ''Fanfic/{{Boundaries}}'' is a ''Pokemon'' story that takes place in the US Midwest of all places.
** ''Fanfic/OverUsed'' is set after the events of the ''Pokemon'' games, and involves an OC veteran trainer and his adventure after meeting a mysterious girl with a Mew companion. It changes several rules of the world and follows different battle tactics compared to the anime or video games.
** Subverted in ''Fanfic/PokemonStrangledRed''. The Pokémon Strangled Red game is initially presented as this in-universe, with Steven seeming to be a cooler version of Red, the protagonist of Pokémon Red and Blue. However, when Steven talks to Red's mother, the narrator realizes that this hacked game takes place in the same universe as Pokémon Red and Blue, only a year earlier, with Red looking up to Steven in a big way.
** ''Fanfic/WelcomeToTheWorldOfPokemon'' is a collection of AlternateContinuity fics for the main series ''Franchise/{{Pokemon}}'' games. The story follows the main heroes, giving them character traits, changing elements of the original story, [[OffTheRails changes the heroes' path through the game]], or a mixture of the three, depending on which story is being considered.
** ''Fanfic/{{Chrysanthemums}}'' is a ''Pokémon'' DarkFic where the Shadow Triad are the Striation Trio. There are various little differences, such as the brothers only becoming gym leaders ''after'' Ghetsis is arrested.
* ''Franchise/DragonAge'':
** ''Coffee, Black'' is a ''VideoGame/DragonAgeII'' fanfic which takes place in modern America. It is written through Garrett Hawke's point of view, while he works in a coffee shop and is practically hypnotized by a mysterious tattoo-covered hipster named Fen. It can be read [[http://archiveofourown.org/works/238633/chapters/366263 here]]. (Warning: as it was originally inspired by a prompt from a KinkMeme, it gets VERY steamy later.)
** The ''Fanfic/TwiceUponAnAge'' series is a retelling of ''VideoGame/DragonAgeInquisition'' in which both male Lavellan and female Trevelyan ended up with the Anchor and must share the duties of being the Herald of Andraste. As a result (direct or otherwise) of this aberration from canon, a number of other things end up being quite different. Among the changes: the Inquisition is able to recruit ''both'' the mages and the Templars, resulting in both Samson and Calpernia leading forces against them in the name of the Elder One. Samson and Calpernia are not working together, however; rather, they're rivals for the Elder One's favor, and he plays them against each other. Other changes include the ball in Halamshiral being resolved in a way not technically possible in the game, and the Inquisition's inner circle receiving an additional member late in the story, when [[spoiler:Bethany Hawke]] comes to Skyhold.
** ''Fanfic/BeyondHeroes: Of Sunshine and Red Lyrium'' is a straight retelling of ''VideoGame/DragonAgeInquisition'' - except that the Inquisitor is [[VideoGame/DragonAgeII Bethany Hawke]], and the story is told from Varric's point of view.
* ''Franchise/MassEffect'':
** ''Fanfic/{{Renegade}}'' is a crossover fic that explores how differently the ''Franchise/MassEffect'' universe would be if elements of the ''VideoGame/CommandAndConquerTiberianSeries'' universe were worked into the continuity, notably being that GDI replaces the Systems Alliance and has enough military prowess to remain independent of the Citadel.
** ''Fanfic/{{Harbinger}}'', by the same author, fuses the ''Franchise/MassEffect'' setting with ''[[VideoGame/FirstEncounterAssaultRecon FEAR]]'', hinting at the ramifications of a ''Mass Effect'' setting where organics begin manifesting a wide range of PsychicPowers and sanity is an optional part of such abilities.
** ''Fanfic/RenegadeReinterpretations'' is set in a ''Franchise/MassEffect'' universe where [[AlwaysChaoticEvil the batarians]] found humanity first and the latter didn't have the lightning-fast tech advancement of canon. The result is a much less nice humanity.
** ''Fanfic/OrdinaryHumanSpectre'' is a crossover AU between ''Franchise/TouhouProject'' and ''Franchise/MassEffect'', revolving around replacing Commander Shepard with Marisa Kirisame, and integrating the ''Touhou'' universe into the ''Mass Effect'' one (Gensokyo is an Alliance military base, Youkai are genetically modified humans, Patchouli Knowledge works for the Shadow Broker, etc.). It goes OffTheRails pretty quickly.
** ''Fanfic/ForTomorrowWeDie'' is an AlternateContinuity fic for ''Franchise/MassEffect'' which picks up immediately at the conclusion of ''VideoGame/MassEffect2''. Written well before the release of ''VideoGame/MassEffect3'', the events of the story prevent the events of the third game from happening at all.
** ''Fanfic/MassEffectHumanRevolution''. Any real detail would go deep into spoiler territory, but suffice to say that the history of the galaxy is a vastly, vastly different one from canon even before the ''Deus Ex''-derived bits come in via Humanity entering the galactic scene.
** ''Fanfic/AndTheMeekShallInheritTheGalaxy'': Instead of turians, humanity meets the quarians first, with the entire ''Franchise/MassEffect'' Universe drastically altering as a result.
** ''[[http://www.fanfiction.net/s/8213106/1/Uplifted Uplifted]]'' is set in a universe where a desperate quarian fleet decided to uplift humanity circa 1942 in order to utilize them as foot soldiers and retake Rannoch. However, contrary to what most people would expect, they choose to ally themselves with the fascists. The choice is logical given what the quarians intentions for humanity. The epilogue strongly implies the war results in a stalemate. The author is planning a trilogy. A fair warning though: the main characters are Nazis, and the author has no problem displaying their attitudes. Unique in that it avoids depicting all Nazis as evil mass murderers, but makes clear how reprehensible the regime is, as the quarians slowly realize just who their allies are. The author certainly doesn't downplay how reprehensible the quarians find their erstwhile allies actions.
* ''Franchise/SonicTheHedgehog'':
** ''Blog/AlwaysHavingJuice'' is an Alternate Universe Fic for ''Franchise/SonicTheHedgehog'', with every single character given a design overhaul, the world being a strange recipe of every other iteration of the ''Sonic'' Canon you can think of off the top of your head, all put through the lens of [[Tropers/CalamityJane one troper]].
** ''Fanfic/{{SONIC|Kojiokida2}}'' is a ''Franchise/SonicTheHedgehog'' AU which is described by the writer as 50% ''WesternAnimation/SonicTheHedgehogSatAM'', 20% ''ComicBook/SonicTheComic'', 10% ''Anime/SonicX'', 10% ''ComicBook/SonicTheHedgehogArchieComics'', and 10% original spin.
** Some [[https://scratch.mit.edu/studios/1173310/ [=SilverAndKaylee15=]'s]] ''VideoGame/SonicTheHedgehog'' {{Script Fic}}s, ''Past Forgotten'' and ''Full of Regrets,'' take place in a timeline where ''VideoGame/SonicTheHedgehog2006'' [[AlternateHistory did happen]], which means Mephiles is the main antagonist, Blaze is Iblis' host, and the [[BadFuture future is ruined.]] For the other stories, like in the canon, [[ResetButton the '06 timeline got erased.]]
** A very different Contextual Reassignment ''Franchise/SonicTheHedgehog'' fanfic is found in ''Fanfic/PrisonIslandBreak'' The entire story not only takes place in a high-security prison, but almost all of the characters (from a wide range of Sonic continuities) are convicted criminals. Their goal to escape prison is neither noble nor heroic since there is no doubt that they are guilty, and most of them are unrepentant. Despite this, the story is popular for keeping all of them in-character, and even their very different criminal backstories still seem to suit their original characters.
** ''Fanfic/HowDoIAdmitImFallingApart'' is set in a world where Sonic was born female-assigned-at-birth and began transitioning between ''Sonic CD'' and ''Sonic 3''.
** ''Webcomic/TheHeartOfAMonster'' is a comic based on ''VideoGame/SonicUnleashed''. In it, Knuckles, Tails, and Shadow help Sonic on his adventure.
** ''Fanfic/SonicComicsRewriteOneChangeCanMeanANewChance'' is a rewrite of ''ComicBook/SonicTheHedgehogArchieComics'' where Snively (or Colin, as he is called in the story) was abandoned by his family when he was two, then adopted and raised by Sir Charles Hedgehog, making him a Freedom Fighter from the very beginning.
* One ''VideoGame/ValkyriaChronicles''[=/=] RealLife double AU, ''Fanfic/BattlefieldGallia'', is set early in the war (November 1940, Operation Sea Lion); but UsefulNotes/WorldWarII as we know it will take place in some shape, albeit in really mutated form. [[spoiler:As of yet, Gallia mostly resembles Poland, and we all know who [[ThoseWackyNazis won there]].]]
* ''Fanfic/HauntedHouse'' is an AU of ''VideoGame/FinalFantasyVII'', in which Sephiroth, Zack, and Cloud decide to explore the abandoned Shinra Mansion in Neibelheim the night before they're supposed to investigate the Mako reactor. They find the coffin containing Vincent Valentine and rescue him. He manages to help prevent Sephiroth's canonical StartOfDarkness, and from their the story follows Sephiroth, Zack, Cloud, and Vincent as they begin to investigate all of Shinra's dirty secrets, paving the way for an all out civil war within Shinra.
* ''VideoGame/DevilMayCry'''s Dante being Nero's father in "[[http://www.fanfiction.net/s/6822576/1/Like_Father_Like_Son Like Father, Like Son]]" ([[spoiler:Which, hell, [[ShrugOfGod might even be canon]], but the generally accepted theory is Vergil]]). SinkOrSwimFatherhood [[HilarityEnsues hijinks ensue]].
* The majority of ''Franchise/TouhouProject'' fanfic falls into this category due to the lack of information from ZUN on just how Gensokyo works. Even fics that apparently take into account all the details released at the time of their writing tend to be {{Jossed}} by new canon and deuterocanon. This may be about to change due to the increasing attention given to world building in official material, but then again ZUN has contradicted himself and retconned certain things on more than one occasion.
** One of the perhaps most well known of these is the ''Fanfic/DaysWovenWithIllusion'' series by Gensoukoumuten, detailing an alternate version of Gensoyou where the barrier was never needed, with magic and science evolving side by side.
* ''Fanfic/MegaManReawakened'' is in a separate universe from the games and animated adaptations.
* ''Franchise/KingdomHearts''
** ''Fanfic/KingdomHeartsTheThirdEpic'', which begins about a year after [=KH2=] and follows the KH crew on a DarkerAndEdgier journey to defeat the Dark Empire, an enemy much more powerful than the Heartless or Nobodies. Also counts as a {{Crossover}} due to the high number of anime that get their own worlds/realms.
** ''Fanfic/RunawayWind'', which diverges from canon in the first game when Sora releases his heart to save Kairi and unwittingly releases Ventus as well, leading him to wake up early and escape from Castle Oblivion with Naminé.
** ''Fanfic/SecondChanceKingdomHearts'', in which Sora grows up able to communicate with Ventus's heart, learning about other worlds and the Keyblade years ahead of canon.
* ''Fanfic/TheLegendOfCynderSeries'' is based off the simple question 'what if Ignitus had grabbed Cynder's egg during the raid instead of Spyro's?', in addition to generally expanding upon the universe of ''The Legend of Spyro''. [[spoiler: It also asks the question 'What if the apes had grabbed Spyro's egg instead of Cynder's?]]
* ''Fanfic/FireEmblemAwakeningInvisibleTies'' is described by its author as a "hybrid" between an AU and adaptation of ''VideoGame/FireEmblemAwakening''.
* ''Fanfic/LivingAtFreddys'' is a ''VideoGame/FiveNightsAtFreddys'' fanfic in which Mike, instead of dying after being caught by the animatronics, is forced to live with them.
* ''Fanfic/SomethingAlwaysRemains'' is a ''VideoGame/FiveNightsAtFreddys'' fanfic that explores what happens if Springtrap is found, empty, during Mike Schmidt’s tenure. Other events from other games end differently, such as [[spoiler: the kid from ''VideoGame/FiveNightsAtFreddys4'' surviving the Bite of '83]] and [[spoiler: [[VideoGame/FiveNightsAtFreddys3 Springtrap]] being haunted by [[VideoGame/FiveNightsAtFreddys2 Jeremy Fitzgerald]] instead of William Afton]].
* ''Fanfic/BondsLeftUnbroken'' is based in a ''VideoGame/ProfessorLayton'' AU where Desmond and Hershel are adopted together, rather than being separated.
* ''Fanfic/HotspringSouls'' is a ''Soulsborne'' (''VideoGame/DemonsSouls'', ''VideoGame/DarkSouls'', ''VideoGame/DarkSoulsII'', and ''VideoGame/{{Bloodborne}}'') crossover comedy fic that plays with the idea of the games' protagonists having a weekend vacation at an inn/hotspring in the countryside.
* ''Fanfic/TheRedWebOfFate'' is a ''VideoGame/ToukenRanbu'' fic that crosses a coffee shop AU, a university AU, and a generic modern AU. Certain minor characters also attend high school.
* A vast number of ''VideoGame/{{Undertale}}'' [=AUs=] have sprung up on Tumblr, including (but not limited to):
** ''Underswap'', in which various major and minor character switch personality and position (for example, Papyrus is a slacker while Sans is the enthusiastic one). Not to be confused with ''Webcomic/{{Storyshift}}'', an AU where characters swap roles but largely retain their personalities.
** ''Underfell'', a DarkerAndEdgier fic in which all characters switch morality, where the monsters are out to kill the Fallen Human and Flowey is trying to help them.
** ''Littletale'', where the monster characters [[SpinoffBabies are kids around the age of the Fallen Human]]. Not to be confused with Baby Bones, an AU that focuses on young Sans playing ParentalSubstitute to an infant Papyrus.
** ''Undersail (AKA Plundertale)'', a nautical/pirate-themed AU where the monsters were banished to the bottom of the sea.
** ''Outertale'', a sci-fi AU where the monsters were [[RecycledInSpace banished to outer space]] rather than the Underground.
** ''Mafiatale/Undermafia'', an AU where the monsters have the personalities of mobsters from TheRoaringTwenties.
** ''Dancetale'', an AU where dancing is SeriousBusiness to the monsters, used for both communication and [[DanceBattler combat]]. Each of the monsters is associated with a style of dancing (Undyne with capoiera, Papyrus with Latin dancing, and so on).
** ''Underfresh'', a tongue-in-cheek AU where the characters are given TotallyRadical personalities and designs inspired by TheNineties.
** ''PTA Undertale'', somewhere between an AU and a ContinuationFic where the Undertale monsters, on Frisk's behalf as their collective guardians, interact with a PTA run by a [[FantasticRacism hostile-to-monsters]] ObnoxiousEntitledHousewife (usually named Helen, in association with the "Fight Me, Helen" meme). Hilarity ensues. (Rather unusually, sometimes ''PTA Undertale'' is combined with another AU, such as ''Underfell'' or ''Underswap''.)
** ''Baby Blasters'', an off shoot of the ''Gasterblaster'' AU, where young Sans and Papyrus can change shape to resemble the Gasterblaster weapons, with the flagship fic being ''Fanfic/{{Trust}}'', as well as a thriving [[http://babyblasters.tumblr.com/ Tumblr Community]].
** ''WebAnimation/{{Glitchtale}}'' is a WebAnimation AU series for ''VideoGame/{{Undertale}}'' centering around the idea of Frisk resetting the timeline so much that what should be impossible starts happening, [[spoiler:such as Frisk performing a FusionDance with Sans]].
* ''Webcomic/ADreamerReborn'' is an AU series supporting ''VideoGame/{{Undertale}}''. It tells the story of what might happen if Frisk sacrifices themself to save Asriel Dreemurr, and allow him to keep his true form.
* ''Fanfic/ANewHope'' is a ''VideoGame/FinalFantasyVII'' drama fic which places the main characters of ''Final Fantasy VII'' into the real world, and completely changes the relationships, personalities, and backstories of the main characters. Namely, Cloud is forced to participate in an arena after his father Sephiroth (yes, you got that right) kidnaps him after killing his mother; Aerith is Squall/Leon's younger sister; Kadaj, Loz, and Yazoo own and operate an orphanage; and Zack is a sexual predator that tried to rape Aerith on two separate occasions.
* ''Fanfic/NewVegasSheasonsStory'' a retelling/novelization AU of ''VideoGame/FalloutNewVegas'' where the Sheason Fisher is the Courier and must survive long enough to take revenge on the man who shot him and left him for dead. This is Sheason's Story.
* ''Fanfic/{{Offspring}}'' is a ForWantOfANail ''The Legend of Zelda: Breath of the Wild'' fic where Mipha proposed to Link early and he accepted. The two were married in secret and had children together. After the amnesiac Link wakes up, he's surprised to find out he has now-adult children.
* ''Fanfic/BaitAndSwitchSTO'' is based on the pre-season 8 version of ''VideoGame/StarTrekOnline'''s Federation storyline, but changes the Borg attack at Vega IX to happen in 2407 to allow for a ''slightly'' more realistic [[OverrankedSoldier promotion rate]] for Captain Kanril Eleya. Later stories in the continuity diverge further (''Fanfic/TheWrongReflection'' is an AdaptationExpansion of the [[DummiedOut now-removed]] mission "The Other Side", moved to 2410 and taking place after the Undine attack on Earth), largely due to author frustration at the official storyline (which came to a head at [[BrokenBase the Iconian War]], with the authors dumping the TimeTravel angle and ending the war wildly differently).
* ''Fanfic/TheWarOfTheMasters'' is based on ''VideoGame/StarTrekOnline'', with canon events spread out over a larger number of years and incorporating new technologies such as ArtificialIntelligence, PoweredArmor, and [[SubspaceAnsible quantum entanglement communication]]. It also includes a race of {{Eldritch Abomination}}s and substantial plots that have nothing to do with game canon, such as an arc involving a group of colonies seceding from the Federation due to government corruption and mismanagement.
* ''Fanfic/YouCanOnlyUseYourOwn'' is based on ''VideoGame/{{Undertale}}'', exploring what would've happened if [[spoiler:Chara's suicide gambit had failed.]]
* The ''VideoGame/LifeIsStrange'' fanfic ''Fanfic/{{Bloom}}'' makes two major alterations to canon: Max is a Transgender trans girl and the game's BigBad, [[spoiler: Mark Jefferson]], is AdaptedOut. This second change has a lot of effects, most notably that Rachel Amber is alive.
* In the ''VideoGame/HarvestMoonDS Cute'' AU ''Fanfic/StormCloudsAndGreySkies'', Claire lives in Mineral Town instead of Forget-me-not Valley. She meets Leia in the ocean, not in Darryl's house.
* ''Fanfic/YokaiWatchTheRewriteSeries'' is a rewrite of the ''VideoGame/YokaiWatch'' games where both Nate and Katie find Whisper together and are given Yo-kai Watches.
* ''Fanfic/WolfInTheStreetsSardineInTheSheets'' reimagines the ''Franchise/{{Disgaea}}'' casts as humans living in a city where the more run-down and crime-riddled areas are known as the 'netherworld'. Most of the gangs are named after various types of monsters, while [[VideoGame/Disgaea4APromiseUnforgotten Valvatorez]] runs a rehabilitation home where he dresses his charges like penguins and calls them his 'prinnies'.
* ''Fanfic/DamonaInTheDetails'' is a VideoGame/YokaiWatch fic set in a world where Nate freed Damona from the Crank-a-Kai (and accidentally became [[AccidentalProposal engaged]] to her).
* ''VideoGame/Persona5'':
** ''Fanfic/TheEvilQueen'' is set where [[AdaptationalVillainy Makoto Niijima]] is the first Palace Ruler instead of Kamoshida. Using {{Blackmail}}, Makoto became [[AbsurdlyPowerfulStudentCouncil the de facto ruler of the school]] and sees the boy with a criminal record as a threat to her intended utopia. There are far greater changes than on the surface, however...
** ''Fanfic/OneYearOfProbation'' removes all of the supernatural elements from the original story, so those who would have become the Phantom Thieves instead how to use investigation skills in the real world to expose corruption and bring down the wicked.
** ''Fanfic/ThePhantomQueen'' is a setting inspired by TheSilverAgeOfComicBooks with Makoto Niijima set as the Phantom Queen, an {{Expy}} of ComicBook/{{Batman}} with various other characters as allies or [[AdaptationalVillainy super villains]]
* [[https://archiveofourown.org/works/29350917/chapters/72095202 OMARI]] is an ''VideoGame/{{Omori}}'' fanfiction, tell what will happen [[spoiler: if Mari pushed Sunny down the stairs instead of the latter]].
[[/folder]]

[[folder:Anime & Manga]]
* ''Fanfic/{{Other}}'' is a ''Manga/DGrayMan'' Fanfiction in which Allen wakes up in an alternate world where the Noahs and the Exorcists are close allies. In addition, in this world he's only 12 years old...?
* ''Fanfic/HonorTrip'' is an extensive ''Anime/DragonballZ'' fanfiction that chronicles an alternate universe where Cell becomes a hero, & makes amends for his previous deeds.
* ''Fanfic/{{Downfall|Bleach}}'' is a ''Manga/{{Bleach}}'' continuity where Aizen never was the villain, instead [[spoiler: Unohana, you know... TeamMom... is the BigBad. Kyoraku and Ukitake follow her. Nel is Primera. Gin and Ran are Soul Society's resident experts on relationships. Rukia dies.]]
* ''Anime/NeonGenesisEvangelion'':
** ''Fanfic/{{HERZ}}'' is both an AlternateHistory and a Continuation ''Evangelion'' fic. Third Impact was avoided [[spoiler:when Rei chose helping Shinji to get into his giant robot and he hurried to help Asuka,]] and the proper story begins twelve years after, following the main characters' lives as they face new challenges in a changed world.
** ''Manga/Evangelion303'': This fic takes the Evangelion characters and places them in an universe similar to the real world where Second Impact did not happen and there are no [[HumongousMecha giant robots]] or [[{{Robeast}} alien monsters]]. Seele is a secret society that has been manipulating world politics during centuries and has been trying to undermine America’s influence throughout the world. To try to avert Seele's ultimate plan to deal with the USA -named Third Impact-, the USA and Japanese governments put in motion the Black Project Evangelion. As a result of this, Nerv is located in America, the Children are at least twenty-year-old, they pilot war planes instead of Super Robots, and Rei and Kaworu are not Angels.
** ''Fanfic/NeonGenesisEvangelionR'' diverges from the canonical timeline at the end of Episode 24 and beginning of the ''End of Evangelion''. Essentially, Gendo anticipates Seele's attack, decides he's not ready for it, and begins a major reconstruction of Tokyo-3 in order to make himself a public hero that is temporarily untouchable. In retaliation, [[spoiler:Seele builds a bunch of faux Angels for the purpose of attacking Nerv and initiating Third Impact in a more plausibly deniable way, while also recruiting another human-like Angel (ala Kaworu) to help them.]] Also, Shinji gets better. As does Asuka. And Rei. And everyone else. [[spoiler:[[BittersweetEnding Well, almost]]]].
** ''Manga/ReTake'' is perhaps the most popular example amongst the ''Evangelion'' fandom. Shinji has a dream which he realizes prophesies the events of ''End of Evangelion'', and resolves to make better choices in order to avoid the bleak outcome of that story. He ends up [[spoiler:getting engaged to Asuka and fathering her child]]. He also learns that [[spoiler:it is he -- not Kaworu -- who is the final Angel, and that his unborn child is half-Angel because of this]]. While Gendo tries to make Shinji reach his DespairEventHorizon by [[spoiler:seemingly letting Asuka die in an Angel attack]], Shinji manages to not be as selfish as he was in the original story and [[spoiler:defeats the Angels and SEELE without triggering Third Impact]]. He and Asuka [[spoiler:eventually rekindle their romance and live happily ever after]].
** ''Fanfic/AGlassOfWine'' branches off continuity after the battle in the volcano, when Misato points out to Asuka that Shinji also feels phantom pains after each mission.
** ''Fanfic/RolePlayingEvangelion'': The story is set at some point after Shinji telling his father off in the aftermath of the battle against Bardiel, but Shinji is still working for Nerv and living with Misato and Asuka, and there is no mention of other Angel attacks.
** ''Fanfic/LongTimeNoSee'' is set in the future of a timeline where the Third Impact did not happen.
** ''Fanfic/ShinjiTheCasanova'': A different Angel drops by Tokyo-3 and Leliel's attack, setting off a chain of events which ends up with Shinji and Asuka getting together, among other changes.
* Gregg "Metroanime" Sharp's ''[[http://www.asynjor.com/fanfic/sharp.html The Bet]]'' is a cycle of stories based around a competition by a group of gods, demons, spirits and the occasional mortal to see who can make the biggest change in one of several "standard" timelines (the {{canon}} versions of ''Manga/RanmaOneHalf'', ''Anime/TenchiMuyo,'' and ''Franchise/SailorMoon'' among others) with [[ForWantOfANail the smallest alteration]]. Each entry in "The Bet" is a small Alternate Universe Fic. ''The Bet'' inspired many contributors and imitators, and turned Alternate Universe Fics into sort of a cottage industry for Sharp.
* ''Manga/{{Naruto}}'':
** ''A Fox in Tokyo'' by Creator/DogheadThirteen is one for ''Manga/{{Naruto}}'', where the main change is that it's set in the author's MegaCrossover Top Dog universe, which includes a modern-day Tokyo where Nerima is a separate country owned and ruled by [[Manga/RanmaOneHalf Soun Tendo]], who is a werewolf. Needs to be seen to be believed.
** ''Fanfic/DejaVuNoJutsu'': Someone with military experience and a like for the Naruto series ends up in Minato and Kushina's generation. Cue events drastically altering the Naruto universe to the point where canon is truly and completely dead[[spoiler: Danzo and Orochimaru are dead long before the "canon" timeline even begins]]. Also, world-building and plot-hole filling abounds.
** ''Fanfic/Team8'': Something (currently a NoodleIncident) happens in Kurenai's past, and when she is tapped to train a genin team, she goes out of her way to request a specific newly-graduated ninja: Naruto Uzumaki. He thus ends up taking Kiba's place on Team 8 (becoming the teammate of Hinata Hyuga and Shino Aburame), while Kiba goes to take his place on Team 7.
** ''Fanfic/DanceOfTheDogGod'' is a ''Anime/{{Naruto}}'' fic where, instead of embracing the rules after his father dies, Kakashi ends up leaving the village, and Team 7 instead ends up training under Obito.
** ''Fanfic/PrincessOfKonoha'' is a ''Manga/{{Naruto}}'' fanfic in which the Hyuuga Clan is far more prominent and influential in Konoha than it is in canon.
** ''Fanfic/SonOfTheSannin'' explores how things could have gone if Jiraiya and Tsunade had chosen to raise Naruto, and stayed around Konoha during those years he grew up. The story then goes on to explore many WhatIf scenarios [[spoiler: such as the Uchiha clan pulling off their planned coup d'etat.]]
** ''[[https://www.fanfiction.net/s/8905731/1/The-Shy-Demon-and-the-Brash-Heir The Shy Demon and the Brash Heir]]'' is a personality swap fic where Naruto became a ShrinkingViolet because he's [[AllOfTheOtherReindeer constantly bullied]] while Hinata became a loud [[ClassClown prankster]] as a way to deal with the stress of being the Hyuuga heir.
** ''Fanfic/WhiteEyes'' is a fic where Neji kills every Hyūga sans Hinata in order to appease the Uchiha from pulling off their coup, as opposed to Itachi killing off members of the Uchiha clan. This results in Hinata to be an avenger while Sasuke doesn't.
** ''Fanfic/WarOfTheBiju'' branches off from the aftermath of Pain’s Invasion, where instead of Danzo becoming the Sixth Hokage candidate, Naruto is the one who receives the position.
* ''Fanfic/YuGiOhRevolutionGathering'': A ''Anime/YuGiOh'' fic where we join a new group of heroes and as one young boy continues his quest to reclaims something he lost.
* ''Anime/CodeGeass'':
** For ''Anime/CodeGeass'', a major point of divergence from the anime's original plot is explored in ''Fanfic/CodeGeassLelouchOfBritannia,'' where the author explores the WhatIf scenario where Lelouch is ''not'' banished from the court, and grows up in Pendragon. The answer? Quite a bit, but with some interesting parallels to the original timeline.
** The ''Franchise/CodeGeass'' fic ''[[http://archiveofourown.org/works/334086 Mosaic]]'' takes place in a world where Britannia prefers to expand its power and influence through [[AltarDiplomacy marriage]] rather than conquest, Suzaku is TheEmperor of Japan, and China made a failed attempt to seize control of the island nation.
** ''Fanfic/OfMonstersAndMen'' is a ''Code Geass'' fanfic where Nunnally was one of the hostages in episode 8. This allows her to reunite with Euphemia earlier than in canon.
* ''Anime/{{Pokemon}}'':
** ''Fanfic/TheRoadYouChoose'' deviates from the ''Pokémon'' anime canon during the movie ''The Mystery of Mew''. The author adds in elements from both the games and the ''Adventures'' manga and meshes them together into her own version of past events, as well as playing a part in future adverts as well.
** ''Fanfic/PokemonTheGreatAdventure'' by Elia41. By a dark and stormy night, young Ash meets a wounded man. Five years later, the two travel across Kanto to challenge the Leagues. Awesomeness ensues.
** In ''Fanfic/{{Symbiosis}}'', Ash's parents are murdered by a mysterious organization at young age. With the help of his father's Mareep, Ash escapes into Viridian Forest and is raised a wild Weedle.
** ''Fanfic/PokemonResetBloodlines'' has a PeggySue premise, with Ash being sent back to the past to [[SetRightWhatOnceWentWrong prevent the collapse of the reality]], while still retaining his experience and memories. However, the transition creates a completely new timeline, and once the story gets going, events begin to play in a ''very'' different way to the canon anime.
** ''Fanfic/TheRoadToBeAPokemonMaster'' is a rewrite of the anime in which Serena moved to Pallet Town several years before the start of the series, and she and Ash begin their Pokemon journey together. It does feature other changes unrelated to this one, most of them being bringing elements from the games the anime [[AdaptedOut left out]].
** ''Fanfic/ANewChanceSeries'' is a ''Anime/{{Pokemon}}'' fanfic where Latios, with Ash's help, survives the events of the fifth movie. Out of gratitude, he and his sister Latias join his team, first in the final part of Johto, and then to Hoenn.
** ''Fanfic/{{Essence}}'' is an AU where Ash wakes up early and gets a Growlithe starter.
** ''Fanfic/ChosenOnesAdventureWithLegendaries'' seems to be a Pokemon anime fic until the end of chapter 3 when Ash gets a Rainbow Wing and suddenly it's a mashup of the anime and all the movies, even those in an alternate continuity.
* A ''Anime/YuGiOh'' fanfic called ''Fanfic/SonOfApophis''. All the character's Yamis become older brothers, with the exception of Bakura, who's an older cousin that [[spoiler:is secretly a half-brother]]. Card games still exist, and it's implied that Yami is still the champion of them, but the tournaments seem to have never taken place. Yami Marik is no where near as psychotic or violent as he is in the actual manga (though he used to be, years ago) and Marik was crippled by his father.
* ''Fanfic/ThePrincessAndTheDragon'' is another ''Anime/YuGiOh'' fic, set in a fantasy universe. Mai is a princess. Yugi is a wizard. Blue Eyes White Dragons are real and Kaiba is the master of them. The Millennium Items still exist (although they are called Shadow Items collectively), and the yamis can all take solid forms. The list goes on.
* ''Manga/SoulEater'':
** It takes place in a new cyberpunk/gothic setting, but ''Manga/SoulEater'' has an AU by Ryo Hoshi called ''Fanfic/ShadowsOnTheWalls'', which has a very strange mix of People In Jars, Lotus Eater Machine, and features some familiar faces traveling as a band...and has the Cargo Ship of Soul Eater Evans and booze. Oh, right, and Maka is a prostitute and Noah [[MemeticMolester does what he does best.]]
** Another one for ''Manga/SoulEater'' would be ''Fanfic/ASoulsSongbook'', which is a result of a single WhatIf involving a switch in who won a battle nearly a thousand years before the start of the canon that ends up turning it into a CrapsackWorld run by the BigBad of the canon, with, among other things, a rare example of CrystalDragonJesus sharing a world with Real Jesus...and the EldritchAbomination cult.
* ''Manga/DeathNote'':
** ''Fanfic/GeniusIsACurse'', a ''Manga/DeathNote'' DarkFic, where Ryuk never drops his Death Note, and Light never becomes Kira, and thus has nothing to alleviate his sheer boredom with. Deals with clinical depression.
** By the same author as ''Genius is a Curse'', a more extreme example of AU. [[http://www.fanfiction.net/s/4382737/1/ It's Just A Game]]. The page description: "It's [[TwentyMinutesIntoTheFuture 2016]] & Light is bored to death. Ryuk offers him the Death Note, a program that lets him wreak havoc anonymously in a virtual world. L pursues this Kira, but when real people start dying, the line between fantasy and reality blurs beyond recognition." L works for Wammy House, the software company making the game, and Ryuk is a disillusioned game programmer they fired. Seems to toy with YourMindMakesItReal.
** In ''Fanfic/ASubtleKind'' is a fic where Misa and Matt's roles in the ''Manga/DeathNote'' universe are swapped.
* ''Anime/{{Nightwalker}}'': ''[[http://www.fanfiction.net/s/1594758/1/STRANGE_PATHS STRANGE PATHS]]'' basically retells the anime story. The only differences are that [[GirlFriday Riho]] is a [[OlderThanTheyLook 140 year old]] vampire and [[VampireDetective Shido]] starts out as an ordinary human detective.
* ''Franchise/FullmetalAlchemist'':
** ''Fanfic/FullmetalAlchemistThreadsOfTime'' focuses on the notion of Alphonse attaching Edward's soul to a suit of armor, and Alphonse obtaining automail limbs.
** The ''[[Fanfic/BloodTies Tiesverse]]'' is a FanVerse that deviates after ''Anime/FullmetalAlchemist'' ends. ''The Conqueror of Shamballa'' never happened and Edward still lives in England two years post-series. Noah (spelled "Noa") is still around but she meets Ed after saving him from Envy. In ''Tiesverse'', homunculus who cross the Gate become vampires. Noa saves Edward from being killed by Envy and turns him into a {{dhampyr}} like herself. Together, they hunt vampires.
** ''Fanfic/SonOfTheDesert'' is a ''Manga/FullmetalAlchemist'' fanfic that asks {{what if}} the Elrics were Ishvalan? The story details Trisha growing up in her village in Ishval and how she won over Hohenheim, how the Ishvalan genocide affected the Elric brothers' childhood and their dealings with the military.
* ''Fanfic/{{ZeonQuest}}'' is a ''Gundam'' AU fic focusing on how one soldier has managed to already permanently alter the Universal Century.
* ''Fanfic/{{Freefall}}'' is a real-world AU crossover fic of ''Manga/TsubasaReservoirChronicle'' and ''Manga/XxxHolic'', among many other Creator/{{CLAMP}} works, that has no magic, time-travel or monsters- and yet manages to be just as complex and involved as the original canon.
* ''Fanfic/NerimaMagistraNellyMagi'' is a retelling of ''Manga/NegimaMagisterNegiMagi'' with [[GenderFlip every character's gender reversed]].
* ''Fanfic/ThoughABirdCantFlyThatDoesntMeanItNeverWill'' is a ''Manga/OnePiece'' "What If?" fic in which Zoro's childhood rival Kuina is blinded instead of killed in her tragic accident. She grows up to be a BlindWeaponMaster who ends up joining the Marines in order to track down Zoro and find out why he's become a pirate.
* Given the nature of ''Webcomic/HetaliaAxisPowers'' and the liberal use of [=AUs=] by Himaruya himself, it's no surprise that there are a good deal of them:
** One example, though a DarkFic one, is ''Fanfic/AllHeEverWanted,'' involving an AlternateHistory where England keeps his alliance with Japan.
** [=AUs=] of the first type (contextual reassignment) are common as well, for example ''Fanfic/PartRightHalfWrongAThirdCrazy''.
** ''Webcomic/HetaliaAxisPowers'' fanfic ''[[https://www.fanfiction.net/s/12086351/1/Kanashī-Wütend-Desolato Kanashī, Wütend, Desolato]]'' is basically a WhatIf for ''[[https://www.fanfiction.net/s/11886910/1/Gankona-Unnachgiebig-Unità Gankona, Unnachgiebig, Unità]]'': [[spoiler:instead of supporting [[{{Polyamory}} Germany's, Italy's, and Japan's relationship]], what if most of the countries scorned and tormented them upon finding out? Things ''do not'' [[DrivenToSuicide turn out well]].]]
* ''Franchise/LyricalNanoha'':
** ''Fanfic/{{Game Theory|LyricalNanoha}}'' is a ''Anime/MagicalGirlLyricalNanoha'' fanfic in which Precia ''didn't'' go completely insane. Although still obsessed with reviving Alicia, she is a great deal more practical in her methods. This has numerous consequences that all follow logically from that divergence, which slowly build up until the plot goes spectacularly OffTheRails [[spoiler:when Nanoha decides to help Precia.]]
** The universe itself has also been tweaked somewhat, as the authors of the story have greatly expanded on the background, and altered several details that weren't internally consistent in the original work, which makes for a smoother narrative flow.
*** And the author also wrote a short AU called ''[[http://www.fanfiction.net/s/8000913/1/Another_Way Another Way]]''.
** ''[[http://www.fanfiction.net/s/7611727/1/Graceful-Degradation Graceful Degradation]]'' is a ''Anime/MagicalGirlLyricalNanoha'' fanfic where the TSAB is prevented from getting involved in the Jewel Seeds incident due to the Arthra getting damaged when Precia moves the Garden of Time while they were in the same relative proximity of it. Events then start to rapidly change from that [[spoiler: such as Nanoha fighting Precia Testarossa herself]], and then goes completely OffTheRails [[spoiler: when the Wolkenritter appear five weeks sooner than in canon]].
* ''Fanfic/LifeAfterHayate'' is an Alternate History of ''Franchise/LyricalNanoha'' where Nanoha's canonical injury between ''A's'' and ''[=StrikerS=]'' does not happen; instead, she is replaced by Hayate Yagami, who is killed and passes the Wolkenritter to Chrono Harlaown with her dying breaths.
* ''Franchise/PuellaMagiMadokaMagica'':
** ''Fanfic/PuellaMagiYuukoMagica'' is a ''Anime/PuellaMagiMadokaMagica'' fanfic in which the world-changing wish that Madoka created is something along the lines of "I want us to no longer be slaves to the Incubators", so now magic is rampant within her world. However, the magic is hidden from {{Muggles}} of course. It's supposed to be a prequel to a seemingly unrelated fic, though. At least Madoka gets to be a LittleMissBadass in this.
** There's also ''Busou Shoujo Madoka ☆ Mafia'', a {{doujin}} series which involves the girls of ''Madoka'' in a mafia setting, with Madoka herself as the BadassAdorable boss of her syndicate and the other girls as her enforcers.
* While the ''Fanfic/TamersForeverSeries'' mostly maintains the same continuity as the canon ''Franchise/{{Digimon}}'' series, it does {{Retcon}} the epilogue of ''[[Anime/DigimonAdventure02 02]]'', as well as the events of ''Runaway Locomon''
* '' [[Fanfic/BlackRockShooterHonestHearts Honest Hearts]]'' by dan-heron turns Mato and Yomi's lovers quarrel into the lid on an even bigger can of worms
* ''Fanfic/TwilightPrettyCure'' is a ''Anime/PrettyCure'' AU. While inspired by the canon series in various ways, it takes more of a serious approach in addressing issues like the evils of bullying, discrimination, child abuse, etc. But it still keeps the "hope within darkness" theme that most ''Pretty Cure'' anime have.
* ''Fanfic/ABriefHistoryOfHistories'' switches around the backstories of each of the [[Franchise/SailorMoon sailor senshi]] and explores how this impacts their characters.
* ''Fanfic/AlabasterOrchestra'' is a ''Manga/{{Bleach}}'' fanfiction which portrays [[TheEmpire the Vandenreich]] [[GreyandGreyMorality more ambiguously]] and diverges [[spoiler: with Ichigo being captured after the invasion of the Soul Society, purged of his Shinigami side, and finally becoming a Stern Ritter of his own free will.]]
* ''Fanfic/LightOfTheSnowRedVillage'' is a ''Manga/RurouniKenshin'' WhatIf that answers the question "What if Kenshin and Tomoe had a daughter?"
* ''[[https://www.fanfiction.net/s/11144592/1/Lum-Sum-Purple Lum Sum Purple]]'' is a ''Manga/UruseiYatsura'' and ''Manga/RanmaOneHalf'' crossover where Shampoo is the one chosen as Lum's opponent, and ends up accidentally married to her.
* ''Fanfic/AGoddessComesToCall'' is a ''Anime/BubblegumCrisis'' and ''Manga/AhMyGoddess'' crossover, where, instead of wishing that Belldandy would stay with him forever, Keiichi wishes for the perfect girl for him, and ends up with Chihiro. Fifty years later, Linna accidentally dials the Goddess helpline and summons Belldandy, then proceeds to accidentally wish that she had a goddess like Belldandy around all the time.
* ''[[http://wariodude128.deviantart.com/art/The-Giant-Has-a-Giant-Mouth-Part-1-546531773 The Giant Has]] [[http://wariodude128.deviantart.com/art/The-Giant-Has-a-Giant-Mouth-Part-2-546534376 A Giant Mouth]]'' is a two part Manga/OnePiece fic that starts by asking what would happen if Luffy was completely taken out of the story and Aphelandra, one of the many women on Amazon Lily, became the protagonist instead.
* ''[[https://www.fanfiction.net/s/9264139/1/Urusei-Yatsura-Love-to-Skate Urusei Yatsura: Love to Skate!]]'' is set in a world where [[Manga/UruseiYatsura Ataru]] WASN'T the one chosen to be Lum's opponent in that fateful game of tag. Among other things, there's no DefeatByModesty (Lum lets Sora, the OriginalCharacter who replaces Ataru, win after he saves her from a nasty fall), and the AccidentalProposal occurs when Ataru goads him into rhetorically asking if he should propose, and it's taken out of context. Also, it's set in TheNewTens, Sora and Ten get on better than Ten and Ataru do, and Kurama is more willing to accept Sora as he is instead of trying to change him (mainly because he isn't a pervert, and his resultant harem is genuinely an UnwantedHarem).
* ''[[https://www.fanfiction.net/s/5273034/1/The_Goddess_and_the_Sky The Goddess and the Sky]]'' has the wish that should have gone to Keiichi going to Sora instead, who proceeds to [[AccidentalMarriage accidentally wish that Belldandy would marry her]]. As a result, Keiichi isn't kicked out of his dormitory, gets an angel named Malaika and is {{Ship Tease}}d with Sayoko, while Sora and Belldandy are forced to leave as their dormitory room is only supposed to have one occupant and end up renting a haunted apartment occupied by Erdgeist, an Earth Spirit Third Class.
* ''[[http://archiveofourown.org/works/6548812 Magic Spells]]'' is set in a world where [[Anime/DigimonAdventure Wizardmon]] is Hikari's partner instead of Gatomon. Also, [[Anime/DigimonAdventure02 Stingmon]] is part of Myotismon's army, and [[Anime/DigimonFrontier Kouichi Kimura]] exists in the same world as the Adventure team.
* ''[[https://www.fanfiction.net/s/84916/1/Angel-Hearts Angel Hearts]]'' is a ''Anime/DigimonAdventure'' fanfic where [[spoiler: Wizardmon manages to survive his HeroicSacrifice thanks to Gennai, and joins the Digidestined in destroying Myotismon]].
* ''[[https://www.fanfiction.net/s/199695/1/KeySeeker KeySeeker]]'' and its [[https://www.fanfiction.net/s/960839/1/KeySeeker-The-Movie sequel]] takes place in a world where [[Anime/DigimonAdventure02 Ken Ichijoji]] ran away to the Digital World as a child, and now serves as the Digital Paladin, guardian of the Digital World.
* ''Fanfic/ACertainUnknownLevel0'': It's a ''LightNovel/ACertainMagicalIndex'' fanfic. While Mr Question Mark does try to incorporate most of the revelations revealed by retconning his story to fit, other elements came too late and had to be left out, such as Shokuhoku knowing Touma before the events of the series; Kamisato Kakeru and his faction along with the Anti-Art Attachment being deliberately ignored.
* ''[[https://www.fanfiction.net/s/4596176/1/A-Clean-Slate A Clean Slate]]'' is a ''Manga/RanmaOneHalf'' fanfic in which Ranma loses the challenge in the Amazon village, and is inducted into the tribe as an Amazon.
* The ''Fanfic/CardinalKing'' series is set in a world where [[Franchise/SailorMoon Mamoru]] is the HenshinHero instead of Usagi.
* ''[[https://www.fanfiction.net/s/7943103/1/Adventures-in-Womanhood Adventures in Womanhood]]'' is a ''Manga/RanmaOneHalf'' fanfic in which the springs of Jusenkyo are permanent. Ranma goes to the Amazons for help adjusting to her body leaving her panda father with the guide. She fights Shampoo for a place in the village and gets training in the amazons ways and fighting. Another elder hates outsiders and plans to kill Ranma but Ranma beats her and her traitorous plans are discovered. Ranma goes home to meet her mother and is accepted. She goes to Furinkan and becomes friends with Akane and quickly agrees to train her.
* ''Fanfic/ContractLabor'' is a ''Manga/LoveHina'' fanfic set in a world where Keitaro ISN'T an ExtremeDoormat. Also, Motoko, Su, Shinobu and Sarah are older than they are in canon, and Nyamo-Chan becomes a tenant at Hinata House alongside the other girls.
* ''Fanfic/LoveHinaLikeItCouldHaveBeen'' diverges from canon when [[Manga/LoveHina Keitaro]] runs into Haruka before entering the Hinata Inn and learns of the games Granny Hina is playing. When the girls refuse to accept him as manager, he simply leaves, and the girls are stuck with all the chores and maintenance he would have done.
* ''[[https://www.fanfiction.net/s/12953442/1/The-Key-to-Victory This is the key to Victory]]'' is set in a world where [[Manga/UruseiYatsura Ryuunosuke]] is chosen as Lum's opponent in the tag game, and ends up making an AccidentalProposal when Lum misinterprets her declaration that she will never let Lum go (before she can grab the Oni's horns) as a marriage proposal.
* ''[[https://www.fanfiction.net/s/2649455/1/I-ll-Be-Seeing-You I'll Be Seeing You]]'' is set in a world where [[Manga/LoveHina Keitaro]] is blind, and Shinobu is slightly older than in canon.
* ''Fanfic/{{Dominoes}}'' is the ''Manga/CaseClosed'' cast in the world of morally ambiguous Superheroes, with Shinichi as a reporter, Yusaku as an {{Expy}} of Batman, and Ran, Aoko, Kazuha, Hattori, and Hakuba as [[{{Expy}} Expies]] of the Teen Titans. And Kaito sees himself as their HeroAntagonist, of course.
* ''[[https://www.fanfiction.net/s/6041027/1/Ah-My-Valkyrie Ah! My Valkyrie!]]'' revolves around [[Manga/AhMyGoddess Lind]] being asked to fill in for Belldandy, and thus being the one to grant Keiichi's wish of having a goddess to stay with him forever.
* ''Fanfic/InTheCircleOfElementalArms'' is an ''Manga/OuranHighSchoolHostClub'' set in a world where ElementalPowers exist.
* The ''[[https://archiveofourown.org/series/1254428 PicoDevimon, Chosen Digimon of Light]]'' series is set in a world where [[Anime/DigimonAdventure DemiDevimon]] is Hikari's partner instead of Gatomon.
* In ''Manga/JoJosBizarreAdventure: [[Manga/JoJosBizarreAdventurePhantomBlood Phantom Blood]]'', before [[BigBad Dio]] discovered the [[ArtifactOfDoom Stone Mask]]'s [[OurVampiresAreDifferent true purpose]] and used it to reject his humanity, he was planning to kill [[TheHero Jonathan]] with it to MakeItLookLikeAnAccident. The {{doujinshi}} ''[[https://mangadex.org/title/12979/jojo-s-bizarre-adventure-towa-ni-shinu-made-doujinshi 'Till we Eternally Rest]]'' explores what would have happened had he gone through with this original plan. To wit, [[spoiler: Jonathan runs away from home and spends the following years fighting off his HorrorHunger while searching for a cure, and Dio becomes the sole heir to the Joestar family, but is unable to celebrate due to the fear that Jonathan may someday come back for revenge. Meanwhile, [[TheHeart Speedwagon]] and [[TheMentor Zeppeli]] find themselves at odds over whether to protect and help Jonathan, or MercyKill him before he can lose control and hurt someone.]]
* ''Fanfic/MarriageOfHeavenAndHell'' is a fic of ''LightNovel/HighSchoolDXD'' where the hero is a CelibateHero Angel with [[AccidentalPervert Accidential]], CovertPervert tendencies instead of an unabashed ChivalrousPervert Devil thanks to a CosmicRetcon caused by Halja, the Goddess of Death.
* ''Fanfic/FrozenMoonlight'' is a ''Manga/RurouniKenshin'' fanfiction where the main characters are modern day high school students.
* ''Fanfic/AlwaysAdvancing'' has Yukari Akiyama, the loader of [[Characters/GirlsUndPanzerOaraiAcademyAnglerfishTeam Oarai's Panzer IV]] in ''Anime/GirlsUndPanzer'', wake up in an alternate timeline where her school was never was able to revive its Sensha-do program and subsequently shut down. The story follows her attempting to [[Main/PuttingTheBandBackTogether locate where her old Oarai comrades are]] while being part of the Sensha-do team at her new school, Saunders.
[[/folder]]

** ''Fanfic/NeonGenesisEvangelionR'' is one example of such a fic, diverging from the canonical timeline at the end of Episode 24 and beginning of the ''End of Evangelion''. Essentially, Gendo anticipates Seele's attack, decides he's not ready for it, and begins a major reconstruction of Tokyo-3 in order to make himself a public hero that is temporarily untouchable. In retaliation, [[spoiler:Seele builds a bunch of faux Angels for the purpose of attacking Nerv and initiating Third Impact in a more plausibly deniable way, while also recruiting another human-like Angel (ala Kaworu) to help them.]] Also, Shinji gets better. As does Asuka. And Rei. And everyone else. [[spoiler:[[BittersweetEnding Well, almost]]]].

** ''Manga/{{RETAKE}}'' is perhaps the most popular example amongst the ''Evangelion'' fandom. Shinji has a dream which he realizes prophesies the events of ''End of Evangelion'', and resolves to make better choices in order to avoid the bleak outcome of that story. He ends up [[spoiler:getting engaged to Asuka and fathering her child]]. He also learns that [[spoiler:it is he -- not Kaworu -- who is the final Angel, and that his unborn child is half-Angel because of this]]. While Gendo tries to make Shinji reach his DespairEventHorizon by [[spoiler:seemingly letting Asuka die in an Angel attack]], Shinji manages to not be as selfish as he was in the original story and [[spoiler:defeats the Angels and SEELE without triggering Third Impact]]. He and Asuka [[spoiler:eventually rekindle their romance and live happily ever after]].

** ''Fanfic/{{SONIC}}'' is a ''Franchise/SonicTheHedgehog'' AU which is described by the writer as 50% ''WesternAnimation/SonicTheHedgehogSatAM'', 20% ''ComicBook/SonicTheComic'', 10% ''Anime/SonicX'', 10% ''ComicBook/SonicTheHedgehogArchieComics'', and 10% original spin.

* ''Fanfic/DamonaInTheDetails'' is a VideoGame/YokaiWatch fic set in a world where Nate freed Damona from the Crank-a-Kai (and accidentally becomes [[AccidentalProposal engaged]] to her).

* ''Fanfic/WearingRobertsCrown'': Events diverge from canon during Robert's Rebellion - specifically from Robert's arrival at the Red Keep after the sack of King's Landing. Kingdoms rise and fall as the game of thrones plays out and winter approaches.

** ''Fanfic/{{Eleutherophobia}}'' is canon-compliant up until one huge divergence in the last book: [[spoiler:instead of dying with his Yeerk, the real Tom is SparedByTheAdaptation. As a result, Jake is slightly less depressed, he starts a [[TropaholicsAnonymous support group for ex-hosts]] with Eva, and he's able to give an insider's perspective on his Yeerk's actions during the final battle.]]

* ''Webcomic/ADreamerReborn'' is an AU series supporting ''VideoGame/{{Undertale}}''. It tells the story of what might happen if Frisk sacrifices himself to save Asriel Dreemurr, and allow him to keep his true form.

** ''Fanfic/AChildShallLeadThem'' revolves around Swoop gaining the Matrix of Leadership via an accident and becoming Pterodactus Prime, the new leader of the Autobots.

** ''[[https://archiveofourown.org/series/1135949 Metal: Cybertron's Rock and Roll]]'' iss set in a world where the war is nonexistent and the Autobots and Decepticons are rock bands.

** ''[[https://www.fanfiction.net/s/7430603/1/Swarm Swarm]]'' is a ''WesternAnimation/TransformersAnimated'' fanfic where Wasp is a hornet and Bumblebee is (ironically) a honeybee who - despite being male - is capable of becoming a queen [[MisterSeahorse and laying eggs]].

See HighSchoolAU, CoffeeShopAUFic, MagicalGirlAU, SoulmateAUFic, and ModernAUFic for particularly common variants. Contrast ElsewhereFic and PseudocanonicalFic. Some FixFic may take the form of this. See UniversalAdaptorCast for when the work itself regularly does this. Other types, such as MarySue and {{Crossover}} fics, are arguably AU too, but don't get counted as such.

* Subverted in ''Fanfic/PokemonStrangledRed''. The Pokémon Strangled Red game is initially presented as this in-universe, with Steven seeming to be a cooler version of Red, the protagonist of Pokémon Red and Blue. However, when Steven talks to Red's mother, the narrator realizes that this hacked game takes place in the same universe as Pokémon Red and Blue, only a year earlier, with Red looking up to Steven in a big way.