[[quoteright:330:[[ComicBook/InfiniteCrisis http://static.tvtropes.org/pmwiki/pub/images/superboy-prime-punch-330px_BigT_9911.jpg]]]]
[[caption-width-right:330:[[VideoGame/SuperSmashBros Retcon... PUUNNCHH!!!!!]]]]

->'''[[RobotBuddy Pollo the Robot]]''': Why don't you just do what Superboy-Prime did and punch the wall?
->'''[[WebVideo/AtopTheFourthWall Linkara]]''': Oh, I tried that already, Pollo. I ended up hitting the wall for like half an hour and the only thing I got out of it was that Donna Troy [[ContinuitySnarl got a new origin]] and [[WebVideo/TheSpoonyExperiment Doctor Insano]] [[GenderFlip became a guy.]]
->'''Pollo the Robot''': Um, Doctor Insano was always a guy.
->'''Linkara''': Yeah, [[YouKeepTellingYourselfThat just keep telling yourself that]].
-->-- [[WebVideo/TheSpoonyExperiment Spoony's]] review of ''Clones of Bruce Lee.''

An example of a {{Retcon}} caused by forces within the story itself, usually using TimeTravel of some sort to alter history. Rarely is it used purely as a dramatic device; the real function is to paper over [[PlotHole continuity gaps]] and [[AuthorsSavingThrow mistakes]].

For example, let's say that the author of a novel series was dissatisfied at the way she'd killed off a character in an earlier book. Instead of just having him show up and explain that he was OnlyMostlyDead, she has the other characters pulled back in time by an evil plan of the BigBad; in the process, they manage to prevent the events that lead to death of the character, and when they get back, ta-da! There he is, good as new.

Whether or not characters will [[RippleEffectProofMemory remember the pre-retconned state]] depends on the story.

Often (especially lately), Cosmic Retconning is the go-to method for demolishing ContinuityLockOut and drawing in a younger audience. As a rule of thumb, superhero movies are the hottest way to increase readership; thus, the new canon should conform to whatever is playing in theaters or on television. See also RetCanon.

A potential downside to this trope, of course, is that it can invoke a strong sense of ShootTheShaggyDog on previous stories in the franchise. Moreover, if the old versions of the characters ''see'' the end coming for their world and ''realize'' that, at best, they can only save the universe by drastically changing it [[RetGone (perhaps erasing countless people from existence]] and rewriting the personalities of the survivors), the results can be pure NightmareFuel -- and also possibly a source of severe MoodWhiplash if either the outgoing or incoming universe is notably more "carefree and innocent" than the other.

'''Note that this applies only to actual retcons'''; something like ''Film/BackToTheFuture'', where changing the past is part of the original thrust of the story, doesn't count.

----
!Examples:

[[foldercontrol]]

[[folder:Anime and Manga]]
* ''Franchise/{{Transformers}}'', of course, has one of its own: [[http://tfwiki.net/wiki/Unicron_Singularity the Unicron Singularity]], which ripped and tore at the fabric of time and space in a way that essentially opens up a planet-sized plot hole just to make room for itself to fill it.
** The Unicron Singularity didn't exist as this at first, and it was transformed into one by the club comic writers to account for some (admittedly minor) inconsistencies between ''Anime/TransformersEnergon'' and ''Anime/TransformersCybertron''. Mind you, these are only minor in comparison to the humongous plot holes that already populated the rest of the entire ''Transformers'' multiverse, which did not have such a black hole.
** There actually exists a transformer, Vector Prime, who was tasked by [[{{God}} Primus]] to protect the stability of the timeline- in other words, the number of plot holes in Transformers is ''so bad, it is actually an in-universe threat'', and there needs to be someone to keep the holes and inconsistencies from destroying everything. He does his best to fix things (usually retconning them from outside the timeline to cover inconsistencies, but coming in person for tremendous holes like the Singularity) so presumably any inconsistency we see was simply recorded before he got around to it, and our media are [[RippleEffectProofMemory ripple effect proof]].
* Played for laughs in ''Anime/ExcelSaga'', where the Great Will of the Macrocosm has to reset the plot multiple times per episode.
* Done several times throughout the backstory of ''XxxHoLic'' and ''TsubasaReservoirChronicle''. You'd need a diagram drawn by Creator/MCEscher in seven dimensions to figure out the order of which retcon came before which, though. Altogether, they produced several [[CloningBlues clones]], eliminated the royalty of a kingdom as royalty while leaving their children the prince and princess in place (their ancestor from another dimension had to come in to act as a placeholder and keep causality intact), caused reality to not notice that someone had died for several hundred years, at which point it had ''always'' noticed (except for the aforementioned clones and friends), and both added and removed the main character's parents from existence (their existence in-story predated the retcon somehow, and the protagonist managed to survive his parents ceasing to have ever existed via a DealWithTheDevil).
* ''Stone Ocean'', the sixth story arc of ''Manga/JoJosBizarreAdventure'', ends with the antagonist Enrico Pucci recreating the universe. The next story arc, ''Steel Ball Run'', is a ContinuityReboot that takes place in the same time period as the first story arc, ''Phantom Blood''.
* At the very end of the ''Anime/NeonGenesisEvangelion'' manga, [[spoiler: Shinji rejects [[AssimilationPlot Instrumentality]] and causes the ResetButton to be hit. The final chapter takes place in the rebooted timeline, where the Earth is safe, Second Impact never occurred, and the Angels never appeared on Earth]].
[[/folder]]

[[folder:Comic Books]]
* Franchise/TheDCU has done this several times, starting with ''ComicBook/CrisisOnInfiniteEarths''. Usually, it's part of a larger effort to make the characters [[ContinuityLockout more accessible and marketable]]. Usually, [[ContinuitySnarl it fails]].
** ''ComicBook/CrisisOnInfiniteEarths'' did it to the entire DC Universe - the destruction of TheMultiverse damaged the time-stream, changing the histories of many characters who lived on the only surviving Earth, thus removing their pre-Crisis backstories (and their campiest adventures.) Several survivors of other Earths have been rewritten into the new history. (For several years this failed to work properly with PowerGirl, and she shifted between several conflicting origins until the universe found a way to slot her in properly. Or rather, that was the in-universe explanation for her MultipleChoicePast.)
** ''ComicBook/ZeroHour: Crisis in Time'', the first sequel to ''Crisis on Infinite Earths'', was the second universe-wide retcon, caused by [[GreenLantern Hal Jordan]] and Hank Hall going mad and tampering with the timestream. It created the [[ComicBookTime sliding timescale]] that the DCU has used since and altered the backstories of several characters, most notably {{Hawkman}} and the Comicbook/{{Legion of Super-Heroes}}.
** In ''ComicBook/InfiniteCrisis'', [=CoIE's=] second sequel, a group of survivors from the pre-Crisis multiverse try to separate the numerous Earths yet again, leading to the multiverse's retroactive re-creation. It also featured a second, separate cosmic retcon; see below. (The third sequel, ''FinalCrisis'', did ''not'' radically alter continuity.)
** The picture at the top of the page came from ''ComicBook/InfiniteCrisis''. Many of the changes here were caused by Superboy-Prime pounding on the walls of reality, giving rise to the "Superboy Punch!" [[MemeticMutation meme]] as a way of [[HandWave hand-waving]] continuity errors.
*** In what looks almost like a parody, at the end of ''[[Comicbook/{{Legion Of Super-Heroes}} Legion of Three Worlds]]'', he's HoistByHisOwnPetard when he [[spoiler: Ret Cons ''himself'' by punching the Time Trapper, who was his future self. The latter is RetGone outright]].
** ''Comicbook/{{Flashpoint}}'', building off ''Franchise/TheFlash: Rebirth'' mentioned below, boils down to simply a time-traveller mucking things up and the heroes having to fix it. [[spoiler:When TheFlash makes the fixes, he's advised that the VertigoComics and {{Wildstorm}} continuities are fragments of the DCU and need to be merged into a single timeline. It seems to be this merging, not a case of incorrectly repairing history, that causes the retcons.]]
* [[MarvelUniverse Marvel]] uses it less often, usually preferring the more "subtle" SlidingTimescale. This usually prevents the all-at-once changes of a Cosmic Retcon by feeding changes out gradually over decades.
** Marvel had their own Superboy-Prime for a while in the form of Wanda Maximoff, the Scarlet Witch. When her powers shifted from "control of probability" to "able to reshape reality at will" and she went bugnuts crazy, "Wanda did it" became a very popular HandWave for a little while.
*** And before Wanda, they had young [[Comicbook/FantasticFour Franklin Richards]], who used his own reality-altering powers to undo [[DorkAge certain unpopular changes]] to ComicBook/IronMan and ComicBook/TheWasp following ''ComicBook/HeroesReborn''.
** One recent example of a Marvel Cosmic Retcon is the ''ComicBook/SpiderMan'' storyline ''ComicBook/OneMoreDay''.
* The creators of ''ComicBook/ElfQuest'' were forced to do this by ExecutiveMeddling: basically, they lost the rights over a large group of characters, the Wavedancers, created as a spin-off by someone RunningTheAsylum. Because they ''did'' want to keep the overall story, a new group of Wavedancers was created in their place, and the original group was handwaved as a dream brought on by BigBad Winnowill.
* In ''ComicBook/TheSandman'', Delirium threatened at one point to turn Mazikeen into a "a demon half-face waitress night-club lady with a crush on your boss", and "make it so you've been that from the beginning of time to now and you'll never ever know if you were anything else and it will itch inside your head worse than little bugses". Given that Mazikeen ''already was'' a demon with only half a face working at a night-club, it's unclear if Delirium actually did make a Cosmic Retcon (with the original state never being seen by the reader), or if she was just being her usual CloudCuckoolander self.
** This is what happens if enough living creatures share the same dream. If a thousand cats were to dream of a world where they rule over humans then the universe would change so that it had always been that way. Luckily getting a thousand cats to agree to do the same thing is nigh impossible. [[spoiler: Also, this is how humans came to rule the world]].
* Creator/AlanMoore's ''ComicBook/{{Supreme}}'' run starts with the main character finding out that he is not the only Supreme - reality has been revisioned multiple times in history, and all his previous incarnations (be they alternate counterparts, imagined versions or "future" selves) together with all their supporting characters, end up in the Supremacy, a dimension which they turned into a utopia. [[spoiler: Later we find out that his ArchEnemy Darius Dax has a similar thing - all his previous versions go to a dimension called the Daxia.]]
** Much is made of the fact that Supreme (that is, the one starring in the book) ''survives'' the retcon in the first issue, though little of his history or characterization remains the same -- a LampshadeHanging of the fact that Moore's run is a {{retool}} or "soft reboot" of Rob Liefeld's material.
* When characters from MilestoneComics and Creator/ArchieComics' Red Circle imprint started to popping up in the DCUniverse, WordOfGod said that their worlds had been fused with DC's due to the events of ''ComicBook/FinalCrisis''.
** Creator/DwayneMcDuffie alluded to this event in his ''ComicBook/JusticeLeagueOfAmerica'' run and then eventually showed how the continuities were merged in ''Milestone Forever''.
* ''ComicBook/YoungbloodJudgmentDay'' reveals that Book of Hermes is capable of changing reality and [[spoiler: Sentinel]] used it to not only rewrite [[spoiler: his own life]] but also turn whole world into one that [[spoiler: he]] liked.
* ''ComicBook/AvengersForever'' reveals that many events of the past has been staged by Immortus and Space Phantoms, cleaning up many [[ContinuitySnarl Continuity Snarls]].
* In ''Franchise/TheFlash: Rebirth'', it is revealed that Barry Allen's mother is dead and his father, the only suspect, died in prison. For years Barry Allen was one of the few superheroes ''without'' [[DeathByOriginStory a traumatic origin]] and his parents grew up and old without complication; it turns out it is because Barry's archenemy, the Reverse-Flash, went back in time, killed his mom, and framed his dad.
* Creator/JMichaelStraczynski's revamp of ''Franchise/WonderWoman'' has Diana not as the first woman to leave Themyscria and make her way in man's world, but as a survivor of a Themyscria that was sacked when she was a child and who is just now coming into her Amazon heritage. Other characters in the DCU (such as Max Lord) are stunned to find out that few people seem to remember Wonder Woman as she was. Diana's goal is to try setting things right. This revamp [[spoiler: was a GambitPileup between the goddesses Nemesis and Clotho.]] Eventually Diana manages to set everything right, but her ordeal, likened to the ''Odyssea'', was meant to introduce new changes into the ''status quo'', like a [[http://www.geekosystem.com/new-wonder-woman-costume-600/ revised outfit]] and an harder, no-nonsense attitude for Diana, though this too seems to have be retconned by the end of ''Flashpoint'' and into her new series. Wonder Woman's pants (and lack thereof) [[http://www.comicsalliance.com/2011/07/21/dc-the-new-52-panel-comic-con/ were the cause of so much drama]] that for several months they were in limbo, though by the time September 2011 rolled around [[RuleOfSexy she was again pantsless]].
* In the ''[[ComicBook/ArchieComicsSonicTheHedgehog Sonic The Hedgehog]]'' comics, this happens in the ''Mobius: X Years Later'' reality (which is separate from the main canon universe). Damage to the fabric of reality from previous adventures threatens to [[TheEndOfTheWorldAsWeKnowIt completely destroy the timeline]], so Sonic goes back in time to fix it, which results in reality changing - before, Mobius was a {{Utopia}} ruled by King Sonic, where all the villains were either dead or at peace with the heroes. But after the changes, it becomes a totalitarian dictatorship ruled by [[KnightTemplar King Shadow]] and enforced by his SecretPolice. Fortunately, the heroes who [[RippleEffectProofMemory remember the way things are supposed to be]] come together and defeat him, returning things to the way they're supposed to be (albeit still with the alternate history).
** There are also shades of this in Silver's stories; everytime he travels backwards in time, he causes small alterations to the timeline. Just not enough to [[SetRightWhatOnceWentWrong undo]] the BadFuture he lives in.
** Dr. Eggman attempts to invoke this trope in the ''Sonic: Genesis'' storyline - hooking up a Chaos Emerald to the Death Egg II, he attempts to rewrite history so that Sonic never existed... and ends up creating the video game universe instead, though with the Freedom Fighters and Snively with them. Sonic is able to go Super and, in an attempt to [[spoiler:save Sally due to the fact that she was killed before the first Retcon]], resets the universe to its normal state. However, because of that one change, a number of things about Mobius itself is altered.
** Happens again in the ''[[ComicBook/SonicTheHedgehogMegaManWorldsCollide Worlds Collide]]'' crossover with ''Comicbook/MegaMan'', where Eggman and Dr. Willy recreate the Genesis Wave, this time affecting ''both'' their worlds. Though rather than trying to erase Sonic and Mega Man, they alter history so Mega Man is post-''VideoGame/MegaMan10'' (allowing the use of Bass, Proto Man and [[VideoGame/MegaMan8 Duo]]) and Sonic is in the modern video game setting rather than Archie's unique comic universe (for familiarity to non-ArchieSonic readers).
*** [[spoiler:In the final part of the story, Eggman screws up Sonic's Chaos Control, causing some major rewriting in his world that, so far, shuffles the current position of nearly everyone, integrates some game storylines into the Archie continuity, redesigns a number of characters, [[ExiledFromContinuity exiles]] characters created by Ken Penders ([[ScrewedByTheLawyers who are entangled in a lawsuit]]) and [[AbortedArc abruptly aborts the King Naugus and Mecha-Sally arcs]].]]
* Comicbook/DoctorStrange has seen this happen a few times (being pals with Higher Beings will do this). In one storyline he saw the entire world destroyed and recreated except for himself, causing him some psychological distress as he wondered if the people he knew and loved were actually real.
[[/folder]]

[[folder:Fanfiction]]
* In Raven Child's ''Fanfic/TheSmurfetteVillage'' fanfiction series, the events that take place in the fourth story "A Home Through Time" retcon ''WesternAnimation/TheSmurfs''' ninth season (the time-traveling episodes) out of existence, setting things up for the events that take place in the story series proper.
* In the ''FanFic/PonyPOVSeries'', [[spoiler: the Shining Armor Arc ultimately reveals that [[BigBad General-Admiral Makarov]] is an [[HumanoidAbomination Equinoid Abomination]] called the Shadow of Chernobull, which has [[RealityWarper twisted reality]] in order to [[MakeWrongWhatOnceWentRight maintain the Hooviet Empire]], and set itself up to TakeOverTheWorld. When Shining ultimately defeats Makarov by feeding him to [[ClockRoaches the Blank Wolf]], all the changes to reality are [[SetRightWhatOnceWentWrong undone]], with the only ones remembering the DarkerAndEdgier timeline being Shining, Cadence, and Minuette (who, due to being ImmuneToFate, a [[AnthropomorphicPersonification Concept]], and a [[Series/DoctorWho Time Lord]], respectfully, have RippleEffectProofMemory).]]
* In ''FanFic/{{Draknophobia}}'' [[spoiler: the White Dragon Sotrahkun]] is forced to do this when Alduin screw things up extremely badly. He'd created Tears through time that allowed him to summon alternate versions of himself but in the meanwhile breaking time as we know it. [[spoiler: The [[VideoGame/TheElderScrollsVSkyrim Dragonborn, Petra]] is forced to sacrifice herself mend things in the end with the help of Brynjolf, sets the retcon in motion.]] as a result, only [[spoiler: Brynjolf]] remembers the old timeline as [[spoiler: Sotrahkun]] rewrites and actually merges timelines. But it's hinted that [[spoiler: Petra]] will eventually recall everything that happpened, albeit at a different pace.
* The ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' fanfic ''[[http://www.fimfiction.net/story/12347/make-a-wish Make a Wish]]'' has a magic wishing star that grants ''every'' wish made on it. Many wishes are purely physical changes, but a few feature Cosmic Retcons on both large and small scale.
** On the small scale, Rainbow Dash wishes for a chance to meets the Wonderbolts, and finds herself having won a contest she never remembered entering. Yet everypony else remembers her doing so and even remarks that she visited the contest's office on a weekly basis to find out if she'd won.
** On the larger scale, Scootaloo makes the wish that she was Rainbow Dash's sister and wakes up the next day Rainbow's flesh-and-blood little sister. Like Rainbow and the contest, Scootaloo's the only one who remembers anything different in her case. The story focuses on her realizing what happened and dealing with the ForWantOfANail implications.
[[/folder]]

[[folder:Film]]
* The 2009 ''Film/StarTrek'' movie has [[BigBad Nero]] traveling back in time and [[spoiler: killing Kirk's father, radically changing the timeline, creating a brand new continuity.]]
** Oh, [[spoiler: and blowing up Vulcan, and killing Spock's mom.]] Can't forget that!
* ''Film/InTheMouthOfMadness'' has some particularely mind-bending ones. The crux of the story is that horror writer Sutter Cane has become so powerful that his creations have become reality, and the protagonist John Trent finds himself in the fictional setting of his stories. By the time he gets back to the "real world" [[spoiler:his partner Linda Styles has been written out by the writer (not even her boss, who sent them on their mission, can remember her), and Cane's reality-destroying novel was already delivered by Trent to the publishers and has been on the shelves for weeks]], even though Trent just emerged from Hobb's End. The Cane that Trent encountered might also be an AuthorAvatar of the real Cane, who is writing the entire story [[spoiler:of the movie ([[TheFourthWallWillNotProtectYou yes, the one you are watching]])]], Cane might have been influenced by a monolith of {{Eldritch Abomination}}s to change reality so they can transform it into something wholly alien, or [[ThroughTheEyesOfMadness Trent may be particularly insane]].
* Japanese time-travel movie ''Time Slip Yankee'' shows what happens when you mess with your parents first meeting ''Film/BackToTheFuture''-style. [[spoiler: The main character is snap-backed into a retconned timeline where his then girlfriend in now his mother after his parents fell for different people. Everything about his life is different, even his body.]]
* ''Film/XMenDaysOfFuturePast'':
** The events of the movie not only [[spoiler: fix the BadFuture]], but also [[spoiler: alter the events of ''Film/XMenTheLastStand'', bringing Scott and Jean (who's still taken to wearing red) back to life. ''Film/XMenOriginsWolverine'' also gets discontinued, given that William Stryker is different and Logan's flashbacks to his adamantium bonding are those of the first two movies.]]
** BroadStrokes: [[spoiler:While ''Film/XMen1'' probably still happened more or less the same way it did in the original timeline (Rogue's got her white hair), the events of ''Film/X2XMenUnited'' must have been altered for Jean to be alive and one of the good guys, as well as Mystique presumably no longer being a murderous terrorist or Magneto's [[TheDragon Dragon]]. Also, among the few things that remain from ''The Last Stand'' and ''Origins'' respectively are Kitty Pryde/Shadowcat is played by Ellen Page and Beast will become Kelsey Grammer when older, and Wolverine's bone claws.]]
** It becomes obvious that Weapon X plays out differently than originally set forth, meaning Jean's sacrifice at Alkali Lake never happened and her rampage after coming back as Dark Phoenix didn't either.
** When young Magneto exits the film, he says goodbye to Xavier as he did in the first two films. This time, Xavier says goodbye back.
[[/folder]]

[[folder:Literature]]
* ''Literature/{{Discworld}}''
** ''Discworld/ThiefOfTime'': History was literally shattered by a "glass clock" that trapped the AnthropomorphicPersonification of Time, and then patched back together (albeit with some weird gaps and miscellaneous changes) by the History Monks; the plot of the book revolves around the History Monks stopping someone else from making a second clock. It's implied that this [[AWizardDidIt explains]] the prevalence of SchizoTech on the Discworld and some of the continuity gaps from earlier books.
** ''Discworld/{{Mort}}'': The Interface is the physical manifestation of the universe [[DelayedRippleEffect gradually]] retconning away Mort's 'mistake' in not taking Keli's life. More accurately, Mort changed [[YouCantFightFate how history is meant to go]], and the Interface represents the inertia of history Cosmic Retconning it back again.
* In the ''Videogame/{{Warcraft}}'' universe, the book trilogy ''TheWarOfTheAncients'' {{RetCon}}s some parts of Azerothean history due to a few people going back in time (most notably the blue dragonflight going from extinct to having enough members to wage war against all other dragons and some mortals at the same time).
* In the ''Dragonlance Legends'' books, much of the plot revolves around the efforts of various characters to Cosmic Retcon stuff they don't like in the past. Tasslehoff is central to this, because kender who travel through time can change the flow of events. First Tasslehoff tries to {{Retcon}} away the Cataclysm; Raistlin [[spoiler:tricks him into breaking the time-travel device instead]]. Then Raistlin tries to {{Retcon}} away the death of Fistandantilus (since he himself has taken Fistandantilus's place in history), and [[spoiler:succeeds, entering the Abyss instead of being blown to smithereens]]. Finally, Caramon and Tasslehoff [[spoiler:wind up in a future where Raistlin wins, and return to the present in order to {{Retcon}} everything back to normal]]. The plot of ''Legends'' will give you migraines if you think about it too much.
* Jake's death, and the subsequently epic time-and-space-altering events that bring him back from the dead in ''Franchise/TheDarkTower''.
* The book ''Literature/StarbrightAndTheDreamEater'' has one, after Starbright manages to defeat the Dream Eater. She wakes up the next day and finds that every single reference to the "spindle sickness" that the Dream Eater created is instead replaced with a reference to a dangerous pesticide. Every person who got sick from spindle sickness got sick from the pesticide instead, and no-one except her remembers the Dream Eater even existed.
* Averted in the StarWarsExpandedUniverse. Jacen Solo's brother, Anakin, died. Jacen developes the power to use the Force to time travel. Jacen's Sith apprentice is Anakin's girlfriend. Jacen's time travel, however, can only alter the events in his memory, not in reality.
** [[WordOfGod Apparently]], bringing Anakin back from the dead was seriously considered for the ending of ''LegacyOfTheForce'', but they figured that messing with time travel in the Star Wars universe could be pretty messy.
* Used in the StarTrekStringTheory novels. When ''Voyager'' accidentally meddles with the "strings" underlying reality, space starts to unravel. The solution to the entire mess eventually involves rewriting thousands of years of history. An event which actually occurred within the current story (all photons within a certain range being drawn into Exosia, a realm of subspace) is now placed many millennia in the past. The starless Void from the ''Series/StarTrekVoyager'' Season Five opening episode is the result of this event. Its existence is therefore one big Cosmic Retcon, down to the species who developed there but technically didn't exist until a few weeks prior...
* In StarTrekDepartmentOfTemporalInvestigations, one of the characters is completely deleted from history by a particuarly malicious "uptime" villain ("Future Guy" from ''Series/StarTrekEnterprise''). He proudly refers to it as the most satisfying achievement of his career.
* In ''[[{{Stardoc}} Dream Called Time]]'', [[spoiler:Cherijo and Duncan]] end up in an alternate timeline where [[RetGone they never existed]] after [[spoiler:convincing the [[AbusivePrecursors Jxin]] ''not'' to [[AscendToAHigherPlaneOfExistence transcend]] (and inadvertently [[SetRightWhatOnceWentWrong make the universe]] a [[CrapsackWorld worse place]] in the process)]]. Fortunately, the only effects on them are that [[UnPerson they're entirely undocumented]] and that the only people who remember them are those with [[RippleEffectProofMemory ripple-effect-proof memories]]. [[spoiler:Including, somehow, [[CrowningMomentOfHeartwarming their daughter]].]]
* The WellWorld series by JackChalker has this as a power granted by someone who has root access to the Well World's main computer. Nathan Brazil had rebooted the universe at least three times.
* In ''TheWheelOfTime'' this is a ''feature'' of its strongest magical attack, "balefire." Anything hit by balefire is DeaderThanDead, its "thread" burned out of the "Pattern" for all eternity ([[DontExplainTheJoke the Wheel of Time is a loom]]); if it's a living thing, anything it did for the past [amount of time] is undone. This not only stops [[BigBad the Dark One]] from bringing QuirkyMinibossSquad members BackFromTheDead, it can be used to un-die {{main character}}s those villains had killed... but historically the spell was [[DangerousForbiddenTechnique outlawed]], after flagrant misuse and {{Continuity Snarl}}s resulting threatened to [[ApocalypseHow/ClassZ unravel creation itself]].
[[/folder]]

[[folder:Live Action TV]]
* The introduction of Dawn on ''Series/BuffyTheVampireSlayer''.
** And in the spinoff series ''Series/{{Angel}}'', the title character makes a Faustian bargain to have his son retconned into having lived a happier childhood and not remembering his ''real'' life (in which he was raised by a psychopath in hell). As a consequence, everyone else forgot about the boy's existence; so in a sense, it's the exact opposite of the Dawn scenario. CW higher-ups requested the retcon due to the show's dense continuity, which ended up being dumped back into the plot anyway.
* The latter part of ''{{Lost}}'' season 5 concerns the main characters, having traveled to 1977, attempting to prevent the plane crash which initially brought them to the island, thus undoing everything that has happened so far in the series. [[spoiler:It doesn't work, though it does create its own side-effects later on.]]
* Between the old and new series of ''Series/DoctorWho'' occurred an off-screen event called the Time War, removing the Time Lords and Daleks (though Creator/RussellTDavies was [[FirstLawOfResurrection rather reluctant to stick to that]]) and changing the Laws of Time. It's also a handy crutch for any inconsistencies.
** In series 5, [[spoiler:the cracks in the universe]] play a similar role, erasing [[spoiler:Rory Williams and the Doctor]] from history. They got better.
** The Franchise/DoctorWhoExpandedUniverse has a far more insidious form of this with FactionParadox's Paradox [[TheVirus Biodata Virus]]. It latches into the part of your biology linked to the Time Vortex... and makes it so you ''always'' have worked for them and ''always'' will. [[spoiler: The Eighth Doctor was infected, and his timeline nearly destroyed.]]
*** ''The Ancestor Cell'', based mainly around said Faction, features a huge and weird one [[spoiler:with the Doctor's destroyed TARDIS retconning it ''back'', after holding both timelines intact for quite some time, and blasting the sector of space that included Gallifrey into quarks]].
** In ''The Name of the Doctor'', the Doctor's open timestream at his grave on Trenzalore provides The Great Intelligence with an opportunity to successfully retcon the Doctor's entire timeline, and Clara has to intervene throughout the Doctor's history to retcon the retcon. However, as of ''The Day of the Doctor'', the Doctor no longer dies on Trenzalore, so the retcons may never have happened.
** In the 50th anniversary special [[spoiler: Gallifrey's destruction itself is retconned. Instead of destroying it, the Doctors sealed Gallifrey away in a pocket dimension, and Eleven then goes looking for it.]]
** In ''AudioPlay/BigFinishDoctorWho'', Charlotte Pollard being saved by the Doctor causes her to become a [[ParadoxPerson living paradox]] meaning history starts breaking down, the CIA are around in 1937 before they should have been formed and Benjamin Franklin was a President. However after she saves the Web of Time the paradox and these events become part of the Web therefore there is no paradox. TimeyWimeyBall indeed.
* Occurs near the end of ''Series/MightyMorphinPowerRangers''. The villains turn back time to a period a decade or so before, and when the effect was canceled, anything that had changed during the reverse-time led to changes in the present day. Most notably, Aisha had moved to a small African village as a child, and Tanya's AdventurerArchaeologist parents had left her in America rather than the African village.
* Balthazar attempts this in ''Series/{{Supernatural}}'', traveling back in time to save the Titanic: this has the effect of ruining Celine Dion's career, creating 50,000 new souls for Castiel, and preventing the deaths of Ellen and Jo Harvelle. Unfortunately for them, Castiel resinks it at the end of the episode after Fate herself [[WhatTheHellHero calls him out on it]]. The whole thing was on Castiel's orders, in order to create new souls for the civil war in Heaven that he's losing.
* The fourth season of ''{{Fringe}}'' picks up in a timeline that's been cosmically retconned as a result of [[spoiler:Peter being [[RetGone erased from existance]]]] at the end of season 3. The differences are subtle -- the prime universe Fringe Division has a different lineup, Walter is a shut-in, some characters are now strangers -- but most of what happened in the previous seasons seems to have unfolded in the same way, or at least similarly.
* ''Series/KaizokuSentaiGokaiger'' has [[spoiler:the power of the Greatest Treasure of the Universe, which lets its discoverer rewrite the universe to suit their own desires. The Gokaiger ask if it could eliminate [[TheEmpire Zangyack]], and are told that it would be as if Zangyack never existed -- but that they would also erase all of the Franchise/SuperSentai from existence too. They end up rejecting the "wish", deciding to take on Zangyack themselves, because facing impossible odds is what Super Sentai members do, and because they don't want to lose everything that they've gained and become as a result of the hardships Zangyack inflicted upon their lives.]]
* In ''Series/StargateSG1'', a two-part episode in Season Eight involved the team time-traveling back 5,000 years into the past, screwing something up, and then their counterparts in the alternate timeline had to time travel back again to fix it. In the end, [[InSpiteOfANail the only difference]] was that [[CloseEnoughTimeline Jack's pond now had fish in it]].
[[/folder]]

[[folder:Tabletop Games]]
* ''TabletopGame/{{Nobilis}}'' has one of these in its BackStory. Something like 500 years of time were erased, but in an uneven way so that some events moved back the full five hundred years, some a portion of that and some not at all. The souls of all the people on the space colonies this erased are very upset, and seemingly still on the planet they used to live.
** This is also the goal of the [[BigBad Excrucians]]; they attack aspects of reality, causing them never to have existed.
* In ''{{GURPS}} Infinite Worlds'', a retcon is called an "ontoclysm" or "reality quake", described as a cosmic event that can change the past and even the natural laws of a given universe. The game even gives rules for attempting to ''trigger'' one! It has been mentioned that superhero worlds are especially susceptible to reality quakes, and that any world with magic or super-powers could be explained by "shards" of the previous reality existing in the new universe (which sounds much like the DCU's explanations about the various Crisis of Infinite Retcons).
* One of the last adventures for ''DungeonsAndDragons'' 2nd Edition was ''Die Vecna Die!'', in which the titular evil god gains control of the city of Sigil, a CosmicKeystone that lets him restructure TheMultiverse to his whim. He fails, but the city's rightful ruler, the Lady of Pain, can't put everything back together perfectly. This was implicitly meant to explain away the differences between the cosmologies of 2nd and 3rd Editions.
* ''TabletopGame/{{Exalted}}'' manages to have its own equivalent of Crisis on Infinite Worlds during a First Age Historical Event called "The Time of Cascading Years". It was a rare foray into Temporal Mechanics for the series; Creation had split into 700 separate timelines, each one with only a single Celestial Exaltation in it. The timelines each reintegrated when that timeline's Exalt managed to save Creation in some massive way... which took longer for some than others. First Age historians basically ended up hand waving the calendar as 'skipping over' the Time of the Cascading Years in the year count, as some timelines were hundreds or thousands of years older than others. The writers primarily introduced it to allow Player Characters in the First Age to have Multiple Conflicting Continuities about "Who saved what from whom with how many chickens", who got to wield the Aidenweiss, and other sorts of badassery that would otherwise be exclusive to historical [=NPCs=].
* The ''TabletopGame/MageTheAwakening'' {{Sourcebook}} ''Imperial Mysteries'' introduced this as a big trick of archmasters. Via Imperium Rites, they can build off of changes they've already made in the world to alter fundamental truths of reality, retroactively introducing changes to history or cosmology. This is part of how one becomes an archmaster (rendering the facts of one's existence only vaguely remembered to mages and not at all to others), and is the most well understood path to [[AscendToAHigherPlaneOfExistence Ascension]]; you remake the world into one where your transcendence is and always was a fundamental property. RippleEffectProofMemory is possible, but only to archmasters and only while within their [[PocketDimension Golden Road]].
* ''TabletopGame/{{Warhammer 40000}}'': anything and everything can be easily fixed with liberal application of [[HordeOfAlienLocusts Tyranids]]. This is how the [[OldShame Squats faction]] was quietly removed from the product line.
[[/folder]]

[[folder:Video Games]]
* The game ''VideoGame/TimeHollow'' involves the main character "fixing" Cosmic Retcons caused by the game's villain.
* In ''Franchise/TheElderScrolls'' series, the Warp in the West, which among other things, [[spoiler:allowed each of the MultipleEndings of ''[[VideoGame/TheElderScrollsIIDaggerfall Daggerfall]]'' to be true.]]
** Tiber Septim was said to be capable of this. Perhaps the biggest example is the province of Cyrodiil itself, which, before he came around, was all tropical jungle. These days it is more of a temperate forest.
* ''VideoGame/SonicTheHedgehog2006'', in which [[spoiler:the ending writes the game out of continuity,]] though Sonic still [[spoiler:has memories of what happened]].
** And then ''VideoGame/SonicGenerations'' happened, [[spoiler:reintroducing the game as an alternate timeline.]]
* ''VideoGame/CityOfHeroes'' has the [=PsychoChronoMetron=], a device that allows psychics to alter the world. It was only used once; as something of an aversion, it caused a ContinuitySnarl as [[spoiler:the villainous inventor attempts to use it to turn a hero into an ally, without knowing anything about his history. The history of this hero was left... somewhat confused.]]
* This happens in ''VideoGame/SuikodenTierkreis'' whenever the world undergoes a radical change. [[spoiler:The cause of these events is worlds fusing together, the actual retcon part is an effect of the True Chronicle.]]
* The newest ''[[VideoGame/MortalKombat9 Mortal Kombat]]'' game has the Raiden from ''[[VideoGame/MortalKombatArmageddon Armageddon]]'' broadcasting a premonition to himself around the time of the tournament from the first game. The Raiden of the past is now imbued with knowledge of events to come and sets about changing them (hopefully for the better).
** [[spoiler:Failure, thy name is 'Raiden'. Through the inscrutable phrase "he must win", Raiden ends up making things a lot WORSE this time around. By the end of ''VideoGame/MortalKombat3'', his misinterpretation of said phrase leads to nearly every single Earthrealm warrior dead and just in time for the events of ''VideoGame/MortalKombat4'' to begin with a massively stacked deck for the side of evil. It's still a Cosmic Retcon as he averted the Armageddon and possibly sealed Shao Kahn for good...but at a terrible cost.]]
* In ''VideoGame/FableII'', Lord Lucien originally intended to rebuild the Tattered Spire in order to bring back his deceased wife and daughter, but by the time the Hero of Bowerstone gets to him to rescue the other three Heroes who are trapped by him, Lucien decided that the world itself needed a Cosmic Retcon. [[spoiler:However, the Hero of Bowerstone prevents Lucien from accomplishing this and either kills him or lets Reaver shoot him after explaining himself. After this, Theresa gives the Hero the choice of one of three wishes, two of which are in themselves retcons of history.]]
* In ''VideoGame/MegaManX6'', Capcom retconned Zero's death in ''[[VideoGame/MegaManX5 X5]]'', shoehorning him into the plot (if you found and defeated a Nightmare Zero).
* The events of the first game of the ''VideoGame/PrinceOfPersiaTheSandsOfTime'' trilogy are retconned ''twice''. First within the game itself, when the Prince rewinds time at the end of the game and kills the Vizier that kicked off the events of the game, and then again at the end of ''[[VideoGame/PrinceOfPersiaWarriorWithin Warrior Within]]'', inadvertently retconning the Vizier's death, causing him to come back as the BigBad of ''[[VideoGame/PrinceOfPersiaTheTwoThrones Two Thrones]]''. By the time ''Two Thrones'' rolls around, the first game's story has ceased to exist in its entirety, and only the Prince remembers what happened.
* ''VideoGame/FinalFantasyCrystalChroniclesRingOfFates'' has this [[spoiler:as its ending. The Yuris and Chelinkas from every parallel world rewrite reality to prevent the tragic events of the game and resurrect their family. Yuri and Chelinka remember, but nobody else does.]]
* [[{{VideoGame/Drakengard3}} Drakengard 3]] uses this trope as [[spoiler:a central plot device. Accord, a cyborg girl from the Old World who serves as the story's narrator, tries to find a branch where [[EldritchAbomination The Flower]] is sealed away and no Intoner survives. The way alternate timelines are handled has been compared to ''VisualNovel/SteinsGate''.]]
[[/folder]]

[[folder:Webcomics]]
* In ''Webcomic/{{Narbonic}}'', Dave goes on a time-travel adventure. Afterward:
-->'''Dave:''' I guess this proves that time is a closed system, unalterable, our fates inescapable. I guess I'll have a cigarette and brood.
-->'''Mell:''' Since when do you smoke?
* In the WebComic ThogInfinitron, a [[http://www.drunkduck.com/Thog_Infinitron/5061318/ movie producer interested in optioning the comic for a live-action movie]] says his offer hinges on the creators making a change to [[http://www.drunkduck.com/Thog_Infinitron/4916009/ Thog's origin]]. The resulting retcon [[http://www.drunkduck.com/Thog_Infinitron/5064794/ sets off an alarm in a time travel watchdog agency]].
* Deletionism...er, Retconjuration is the [[{{Whatevermancy}} school of magic]] that allows the Titans of ''{{Erfworld}}'' to do this.
* The original run of ''{{Zortic}}'' ended with a fight between two cosmic beings creating a big swirly NegativeSpaceWedgie, which the heroes all fell into. The comic went on hiatus for a short time, and then came back, starting over from the beginning. The original run of Zortic was based exclusively on parodying popular science fiction franchises; the two cosmic beings were arguing over the merit of this. The new version is intended to be more original and less parody-driven.
* Fairly late into ''Webcomic/{{Homestuck}}'', John and an entourage of trolls find [[spoiler:a supposed weapon that could be used to destroy the BigBad]]. It is intangible, however, and [[http://www.mspaintadventures.com/?s=6&p=007998 reaching into it]] causes John's arm to show up ''all over the comic's history''. To help sell the effect, the panels in question (and a few Flash animations) had the arms put in retroactively.
* An explicit power of the BigBad in ''CaptainSNES''. So far, it seems she can only retcon things within the framework of existing backstory, fleshing things out in a way favorable to her... but its implied that at full power, she isn't so restricted.
* The non-canon ''Webcomic/ElGoonishShive'', EGS:NP storyline "Oblivious Wand Waving" features [[http://www.egscomics.com/egsnp/?date=2008-09-12 a wand that does this]] while seeming to do nothing from the perspective of both the user and everyone else around them.
[[/folder]]

[[folder:Web Original]]
* In ''WebVideo/TheSpoonyExperiment'', Linkara punched the wall in order to bring back Spoony a la Superboy Prime, but only succeeded in changing Donna Troy's origin story ''again'' and turning [[GenderBender Dr. Insano into a man]].
* ''WebVideo/ToBoldlyFlee'' works this way for the entire [[WebSite/ThatGuyWithTheGlasses Awesomeverse]], explaining any kind of continuity errors in previous stories as [[spoiler:the PlotHole retroactively screwing with reality, and any future mistakes being the result of the Plot Hole merging with the universe as a whole, effectively ''breaking'' reality]]. Best summed up by this exchange:
--> '''[[WebVideo/TheSpoonyExperiment Doctor Insano]]''': [[spoiler:The PlotHole created havoc because we used to live in a universe that made sense, but now that the whole ''is'' the universe, there is no conflict]].
--> '''[[WebVideo/JesuOtaku JO]]''': But that doesn't make sense.
--> '''[[TheSpoonyExperiment Doctor Insano]]''': Nothing does! Isn't it great? Crazy's the new normal...
--> '''[[WebVideo/LukeMochrieAndTheInners Luke]]''': But I don't want to live in a giant mistake!
--> '''[[WebVideo/TheSpoonyExperiment Doctor Insano]]''': Well tough shit, nothing's perfect kid.
* In ''Literature/{{Worm}}'', part of the author's justification for his rewriting of [[http://parahumans.wordpress.com/2012/02/14/buzz-7-9/ Chapter 7.9]] a day after it was posted was [[spoiler:Coil, the boss of the protagonist's team, had the power to split the world into two timelines and then collapse whichever one he didn't like]].
[[/folder]]

[[folder:Western Animation]]
* In season 2 of ''WesternAnimation/DannyPhantom'', Danny accidentally gets his ghost powers removed by a LiteralGenie, leaving Sam to recreate the event that gave him his powers in the first place, except [[BroughtToYouByTheLetterS she puts a "DP" logo on his suit so that he'll have it in ghost form.]] When she decides it'd be easier to just wish everything back to how it was, she does so, but specifies that the second version of him getting his powers be the canon one, because she really likes how he looks with that logo.
* ''WesternAnimation/{{Futurama}}''
** Fry's travel back in time created his time-copy, which also allowed them to retcon the most [[TearJerker heartbreaking episode]] of the series.
** In fact, the whole Bender's Big Score movie is just made of this trope. [[spoiler:It even leads to a giant rip in the universe by the end when Bender meets all of his past selves hidden in the caves under Planet Express with all of history's treasures and convinces them to all emerge at the same time instead of when they were supposed to, at which point Nibbler exclaims "Everyone out of the Universe!" and eats himself.]]
* In one of the early episodes of ''WesternAnimation/AvengersEarthsMightiestHeroes'', Comicbook/CaptainAmerica's sidekick [[BuckyBarnes Bucky]] is violently killed during UsefulNotes/WorldWar2. Then near the end of the first season, Cap accidentally touches the Cosmic Cube, which grants his greatest desire by [[spoiler: retroactively changing history so that Bucky survived the explosion]].
* All the retcons in ''WesternAnimation/Ben10Omniverse'' are explained by the entire universe getting destroyed and then getting imperfectly recreated by Ben in Alien X form in the seventh [[note]] [[OutOfOrder technically fourth]] [[/note]] episode of the series. One of the main changes is that the [[GeniusLoci living planet]] Primus, which used to be a massive DNA storage for the Omnitrix and which played a major role in season 3 of ''[[WesternAnimation/Ben10AlienForce Alien Force]]'', no longer exists. Whether this means Eunice is also RetGone is unclear; she was ''on'' Primus, but her existence wasn't directly tied to it. WordOfGod is that she's "unlikely" to appear in ''Omniverse''.
* ''WesternAnimation/ScoobyDooMysteryIncorporated'' [[spoiler:ends with one. [[BiggerBad The Nibiru Entity]] is defeated when the crystal sarcophagus it was using to draw power from another dimension is destroyed. This results in the sarcophagus imploding into a black hole and erasing the Entity from existence. As a result, everything is changed to be as if it never existed at all.]]
[[/folder]]

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