%% This page has had three Image Pickin' threads:
%% http://tvtropes.org/pmwiki/posts.php?discussion=1312935989023858900
%% http://tvtropes.org/pmwiki/posts.php?discussion=1325459008040346900
%% http://tvtropes.org/pmwiki/posts.php?discussion=1332288286041310200
%% Please do not start a new IP thread without a suggestion for a replacement image.
[[quoteright:345:[[ComicBook/{{Hawkman}} http://static.tvtropes.org/pmwiki/pub/images/Hawkmancontinuity.jpg]]]]
[[caption-width-right:345:Behold, the [[ContinuitySnarl/{{Hawkman}} Hawk-Snarl]]!]]

->''"Thanagar's champion, ComicBook/{{Hawkman}} can talk to birds. He also can't talk to birds. Sometimes, he can't even speak normally at all! Even if he could talk normally, or to birds, there are no birds on Thanagar, because it does not exist. Hawkman was sent here to study Earthly police methods, because Thanagar's own methods suck! That's OK though, because Thanagar still does not exist! Yet it is populated by peaceful barbarians! Who are stupid, and also warlike!"''
-->-- '''[[http://www.dialbforblog.com/archives/19/ Kirk Kimball]]''', [[http://www.dialbforblog.com/ Dial B for Blog]]

A SharedUniverse can become a very confusing place, and the longer they exist, the more confusing they can become. As new creators come on board and take over, continuity eventually gets tangled, convoluted, and increasingly difficult to pick through. Sometimes, it gets to the point that not even the fans who write Wiki/{{Wikipedia}} articles understand what is and isn't in Laconic/{{canon}}.

It goes something like this: in the beginning, [[TheVerse The Universe]] is created, and it's a blank slate. Everything's new; as such, the creators can do whatever they want to do, create whatever they want to create, throw everything in and have fun doing so. Whatever works, works and whatever doesn't, doesn't. So far, so good.

However, the whole idea of a SharedUniverse is that different creative teams will eventually take over. Sometimes Writer A of Title A will leave and Writer B will take over, while at other times Writer A's character will guest star or make a [[TheCameo Cameo]] appearance in Writers B's title. People being people, those different creators will have their own ideas. They'll have different ideas about what the [[TheVerse 'verse]] should be, about what has worked and what hasn't, what might work and what doesn't.

The new creative team will also want to make their distinct mark on the 'verse and their readership; as such, they'll have their own things that they want to add, [[ArmedWithCanon things they disapprove of and want to remove or ignore.]]

Things that were previously essential may become irrelevant to the new team, and different character traits and events may be emphasized or ignored. They ''change'' things.

When ''another'' creative team comes along, they'll change things even more; they may even completely override the changes made by the previous team to include things that they want to see or to reassert a previous status quo. Unfortunately, sometimes [[UnbuiltTrope what they regard as being fundamental to the original continuity was never even there to begin with]]!

The longer that this goes on and as more teams take over, the chances of Continuity Snarls taking place go up. The more {{retcon}}s are made, {{reset button}}s pressed, and the more the 'verse enters into a DorkAge.

There is also a bigger chance of certain things simply being forgotten and overlooked (and then possibly rediscovered and revived). As the process continues, more things become confused, convoluted and [[ContinuityLockOut impenetrable]]. Weird inconsistencies and gratuitous {{retcon}}s proliferate. Drastic changes opening up dozens of potentially fascinating story-lines are introduced and then promptly forgotten about and left hanging (or immediately reverted) by another new team, which goes on to do something completely different.

And add to this the problems caused by ComicBookTime, it gets to the point that trying to keep things straight becomes a nightmare.

And that's just if there's only one main work in the Shared Universe to begin with -- if you [[CanonWelding bring together many different characters and storylines]] set in the same universe and [[CrossOver cross them over]] with each other, you have ''many different continuities going on at once''. Trying to keep everything straight between them can be an exercise in complete madness, as the continuity between them is completely tangled up and near-impossible for anyone to unpick.

Unfortunate, if you have a fan-base which likes everything arranged in a neat, tidy little pattern and isn't shy about voicing their opinion when this isn't the case.

This is particularly a problem for comic books, especially in Franchise/TheDCU and the Franchise/MarvelUniverse, which have the long-running and tangled continuities of many a character to keep straight. Long-running TV franchises can also suffer from Continuity Snarls -- the ''Series/DoctorWho'' and ''Franchise/StarTrek'' universes have gotten especially snarled over time (although the former can easily HandWave this away because it's about [[CosmicRetcon time travel]]).

A Continuity Snarl can result in ContinuityLockOut for readers, especially newcomers, as it becomes increasingly difficult to keep track of what's happening in the 'verse without a Masters Degree in Continuity Studies. Creators often resort to the CrisisCrossover to try untangling the snarl they've made for themselves -- unfortunately, this can just as easily become ContinuityPorn, which more often than not just makes things ''worse''. Can lead to a plain ol' PlotHole.

When {{canon}} becomes too involved and self-contradictory, it starts denying new writers "room to move." When writers disagree strongly with what previous writers before them have added to the mix and are overly keen on using continuity to get rid of them (or attack the other writer), then the snarl may come from the writers being ArmedWithCanon. If worse comes to worst, the writers may simply perform a ContinuityReboot, discarding the old continuity completely and starting over from scratch. (Everything you read or watched before? It ''never'' happened! You ''imagined'' it! Either that, or it was AllJustADream.)

Every once in a while, the writer may just give up trying to fix everything and say, [[BroadStrokes "Okay, it happened but not in every detail."]] ContinuityDrift is when a {{Retcon}} sloooowly happens over a period of time. Do not confuse with a SeriesContinuityError. A ContinuitySnarl is when a situation involves layers upon layers of contradictions. A SeriesContinuityError is a singular mistake.

Eric Burns of Websnark did a rant about it [[http://www.websnark.com/archives/2008/01/retconning_just_1.html here.]]

See ArmedWithCanon, ComicBookTime, and AuthorsSavingThrow for common causes, may result in ContinuityLockOut, ContinuityPorn, TangledFamilyTree, and TimeyWimeyBall. MultipleChoicePast is this trope applied to a single character.


* ContinuitySnarl/ComicBooks
** ContinuitySnarl/DonnaTroy
** ContinuitySnarl/{{Hawkman}}
** ContinuitySnarl/OnslaughtReborn
* ''ContinuitySnarl/XMenFilmSeries''
** ''ContinuitySnarl/XMenFirstClass''


[[folder:Anime and Manga]]
* ''Anime/EurekaSevenAO'''s entire backstory. ''(deep breath)'' Eureka is clearly from the original, yet the spec2 she pilots is the movie iteration (the original never had shoulder-mounted lasers). She's also piloting the spec2 well after it should have evolved and subsequently vanished, alongside Renton in the evolved version, and there's no explanation as to where she got this one. TheEnd is in Generation Bleu's basement, intact and in its white color scheme,[[spoiler: although shortly after being freed from said basement it gets vaporized by an IFO [[AssPull that comes out of nowhere]]]]. Oh and at the end of the anime [[spoiler: Renton is piloting the Nirvash's final form from the movie adaptation]]. None of this is ever sufficiently explained. Although since the continuity with the original show and/or movie makes no sense, it can't be in the continuity of the original show. You're welcome.
* ''Franchise/DragonBall'' gets this a lot with all the stories introduced over the franchise's lifespan. Any one entry will be fairly consistent with the manga and/or the anime, but thanks to ShrugOfGod and RuleOfCool they are very rarely consistent with ''each other'' unless they are direct sequels to one another.
** The most relevant example today is ''Anime/DragonBallSuper'', which is generally considered to overwrite anything from ''Anime/DragonBallGT'' due to the involvement of creator [[Creator/AkiraToriyama Akira Toriyama]]... except he also is involved with [[Manga/DragonBallSuper the manga adaptation]] that depicts events differently, and both of those cover the stories from ''[[Anime/DragonBallZBattleOfGods Battle of Gods]]'' and ''[[Anime/DragonBallZResurrectionF Resurrection F]]'' that were both written by him... which are also slightly different!
** Another example is Bardock and the origin of Goku. ''[[Anime/DragonBallZBardockTheFatherOfGoku Bardock - The Father of Goku]]'' had Goku sent to Earth and surviving the Saiyan genocide completely by accident, and Toriyama liked it so much he had Bardock appear in a one-panel cameo later in the manga. Many years later, a special ''Dragon Ball Minus'' chapter in Toriyama's ''Manga/JacoTheGalacticPatrolman'' had Bardock send Goku away as a precaution due to odd orders from Frieza, and is depicted as a [[LighterAndSofter much less savage character]].
** Filler from [[Anime/DragonBallZ the anime]] can be quite prone to this due to inventing stories and facts [[OvertookTheManga to pad for time]] that are contradicted later by [[Manga/DragonBall the manga]]. The [[NonSerialMovie Non-Serial Movies]] get this as well, because while filler arcs sometimes reference them later, they still cannot fit into the show's timeline. Examples from both include:
*** In ''Anime/DragonBall'', Master Roshi recites a story of the origin of the Dragon Balls involving a singular gem that is split into seven after misuse. Two years later, Toriyama would write that they were created by the Guardian of Earth atop a lookout tower. The anime went with that and forgot all about the original tale.
*** Also in the original ''Dragon Ball'' anime, a filler episode reveals the creator of Android 8 to be Dr. Frappe. Five years later, Toriyama would reveal Dr. Gero as the creator of the Androids, and makes the relationship explicit with the title page of Chapter 367 the next year showing Android 8 in a diagram of all the Androids.
*** In one filler episode of ''Dragon Ball Z'', Goku's space pod is destroyed by Piccolo as it turns Gohan into a Great Ape. Not two months later, Toriyama would have Capsule Corp use it (in tact) to build a ship for Goku's trip to Namek. Though since [[OffscreenRebuilding it was recovered and rebuilt completely offscreen]], not to mention into a much larger ship, it's possible to HandWave this as Capsule using the ''remains'' of Goku's pod. Only now the pod is located ''very'' far away from Mount Paoz where Grandpa Gohan found Goku in the manga.
*** In episode 20 of ''Z'', King Kai reveals that the Saiyan homeworld was destroyed by the planet's Guardian with a meteor shower, matching Raditz' story from when he first appeared in the manga. Three months later, Toriyama has Dodoria reveal that Frieza destroyed it in fear of how strong the Saiyans were becoming, which the anime would stick to thereafter. This gets further worsened when both would show King Kai being ''well'' aware of who Frieza is.
*** After Frieza's defeat on Namek, in a filler episode Vegeta implies that now that Goku and Frieza are out of the way, there's nothing to stop him becoming the ruler of the universe. He fights Gohan, then leaves. The next episode, he is back with the main group, has no intention of ruling the universe in Goku's absence, and even comes up with the idea on how to use the Dragon Balls to bring him back so that he can learn the secret of becoming a Super Saiyan.
*** The Garlic Jr. filler arc features the return of the titular villain, returning from the movie ''Anime/DragonBallZDeadZone''. Except in that movie everyone acts as if they're meeting Gohan for the first time and it overwrites the start of Z with Raditz, who is [[ForWantOfANail in a roundabout way]] the reason why Goku is dead and can't appear in the Garlic Jr. filler arc!
*** Also in the Garlic Jr. filler arc, Gohan reunites with the dragon Hire, who he rescues in ''Anime/DragonBallZTheTreeOfMight''... which cannot possibly have happened, because in that film Goku uses the Kaio-ken technique taught to him by King Kai when he was dead, and by the time he's returned to Earth, Yamcha, Tien and Chiaotzu are dead... all three of which appear in ''The Tree of Might''. Many of the other films have similar logistical nightmares involving which characters are dead and/or the specific moves they know.
** Ignoring all of the above, the many different dubs made have introduced their own elements that have to be dealt with, such as [[MemeticMutation Goku's father being a brilliant scientist]], or how heroic Goku is. One particularly amusing case was fans swearing up and down that the villain from ''Tree of Might'' stated that he's Goku's brother, which other fans swear up and down never happened, both citing directly watching their dub as evidence. As it turned out, that detail was only in the UK dub of the movie!
* Despite mostly having only one writer, the classic ''Manga/AstroBoy'' series turned into a first class continuity snarl towards the end. What happened was that in the final episode of the original anime, Astro died performing a HeroicSacrifice to deliver a device into the center of the sun to stop it from dying. Shortly after the anime ended, Creator/OsamuTezuka began a new Astro Boy story as a newspaper strip in the Sankei Shimbun newspaper, which featured Astro's melted carcass being recovered by time-traveling aliens and brought back to life before winding up trapped in the distant past (the readers' present). Because Astro had never died in the manga, however, when the collected edition came out Tezuka redid the first chapter that involved Astro, alive and well getting thrown back in time when the alien timeship crashes on Earth instead. Tezuka then produced three more different, contradictory stories of Astro's future in various publications: a pilot for a second Astro Boy series that never got off the ground which also takes place after the end of the anime where Astro is found by a completely different race of time traveling aliens, upgraded into a new body with time travel capabilities and sent back to Earth to find the era he came from; a one-shot nostalgia piece in a men's magazine, yet another followup to the anime where Astro is resurrected by {{Sufficiently Advanced Alien}}s and taken to a planet millions of light years from Earth from which he may never return, so Ochanomizu and the rest of the Ministry Of Science staff create a replacement, who turns out to be a lazy sex maniac because he was designed to be more "Human"; and finally, "The End Of Astroboy", which doesn't mention his death and simply has him in a display case in a robot museum due to being supplanted by more advanced robots and then freed by some human rebels to help them fight against said robots who have taken over the world.
* ''Anime/{{Pokemon}}'' has some of these, particularly concerning Jessie, James, and Meowth. This can overlap with MultipleChoicePast. Also Brock's mother. The Japanese original said both parents had abandoned Brock to raise his younger siblings, but the English dub gave him an absentee father and a dead mother - awkward when his Mom shows up in a later season.
* Like ''Digimon'' below, ''LightNovel/{{Slayers}}'' has clearly stated AlternateContinuity, and it's actually a bit milder here--the different continuities begin to form after the stories that compromise the first eight [[LightNovels books]], or the first two seasons of the anime, both of which are similar enough to avoid too much confusion. It's still complicated, however:
** In the novels, Lina actually meets Amelia's father, Prince Phil, and gets involved with his family feud ''before'' the series proper--the story of the first ''Slayers Special'' novel was transferred into the middle of the anime's first season: the same plot occurs, but Lina actually meets Amelia, and it goes from there. Also, the Atlas City story occurred right after the very first fight with [[BigBad Shabranigdo]], but the anime cuts to the aforementioned family feud, and the Atlas City story occurs during the second season. This makes little sense in context because in both the first book and the first episode, Lina is on her way to the city. Finally, Amelia appears after the battle with [[BetaTestBaddie Copy Rezo]] in the novels, appearing in another Saillune royal family plot that was ''also'' implemented in the second anime season. Because she joins Lina earlier in the anime, she is with them during the Copy Rezo fight, and also meets Zelgadis earlier on.
** For the anime, there's three more seasons of original stories (and apparently, the third season [[CreatorBacklash was disliked by the creator of the novel series]]). It gets more troublesome when one realizes that [[UnCanceled the fourth and fifth seasons came eleven years after the third]], and the third season overall may be up for an official CanonDiscontinuity by Hajime Kanzaka because of the aforementioned backlash.
** The remaining seven novels remove Zelgadis and Amelia and replace them with Luke and Millina, and from there comes its own story.
** Before he appears again in the fifth book, Zelgadis actually meets Xellos before the others do, hence why he knows of him when he appears. This is accounted in a side story.
** There are a bunch of manga series that are ''their own'' sets of continuity. The most notable is the HotterAndSexier universe of ''The Hourglass of Falces'', in which all six protagonists (Lina, [[IdiotHero Gourry]], [[GenkiGirl Amelia]], [[JerkWithAHeartOfGold Zelgadiss]], [[HotBlooded Luke,]] and [[TheStoic Millina]]) are together. Naturally, the latter four never met one another at any time, and it would probably be impossible, given that [[spoiler:both Luke and Millina are dead by the end of the series]]. Fans outside of Japan who are unaware of the second set of novels ([[NoExportForYou as only the first eight were translated]]) probably don't know who Luke and Millina are.
** The radio dramas are also rather bad at this. The worst case is the ''Slayers Premium'' radio drama based on the short NonSerialMovie: because of the presence of Gourry's [[LaserBlade Sword of Light]], it's likely that it takes place after the second season of the anime. However, in the prologue of the drama, Amelia states that it had been ''five years'' since they last met-problematic, since the anime seasons each occur within one year of the other. ''Premium'' also, of course, has its own manga adaptation.
** Finally, there are cases of the dreaded MultipleChoicePast, especially in regards to Zelgadis. It's never mentioned in the anime, but in the novels it's stated that he was a criminal during his time with Rezo after he was initially turned into a chimera, and it gave him a bad reputation. Also, the applications of magic vary heavily to the point of convolution.
* The various works of Creator/LeijiMatsumoto, which often share characters and have a tendency to re-tell stories from different points of view. Examples include:
** ''Anime/CaptainHarlock'''s ship, ''Arcadia'', has two vastly different appearances throughout the shows in which it appears. Although this change was supposedly made due to a copyright conflict, no explanation is ever mentioned within the show. "Endless Odyssey" takes this to an extreme by showing one version in present times, and the other version in flashbacks.
** Tochiro, the man who build the ''Arcadia'', dies three different times in three different ways.
** The film "My Youth in Arcadia" explains how Harlock lost his eye and gives him a military career before he turned to piracy. However, some shows such as "Cosmo Warrior Zero" neglect to include his lost eye at all.
** In "Space Pirate Captain Harlock" And "Endless Odyssey," Anime/QueenEmeraldas and Tochiro have a child named Mayu, who is never mentioned in any other series.
** Some shows hint that Emeraldas and Maetal of Galaxy Express 999 may be sisters, even twins, despite the fact that in some of the shows the two are introduced for the first time.
** Even more oddly, some speculation links Captain Harlock and Mamoru Kodai/Alex Wildstar as the same person. According to who you ask, they are either literally the same person, or Kodai pretended to be Harlock for his conveniences. Or something.
** Similarly, most series have Torchiro and Harlock's friendship stretching back to their childhood, but "My Youth in Arcadia" shows them meeting for the first time while in the military.
** Mimay has a radically different appearance from series to series: In most she has blue skin, blue hair, yellow eyes, and no mouth, but in a few instances, she is a rather normal-looking woman with blond hair and pale skin.
** The series ''Captain Herlock: Endless Odyssey'' makes a valiant attempt to maintain continuity, and picks up with most of the main cast, including Harlock, Mimay, Kei, and most of the back-characters. Despite this, Tadashi Daiba's role manages to play out almost exactly as it did in previous series.
** There is a glaring canonical gap of about 800 years between these overlapping stories. The character's apparent immortality is never mentioned.
** It can be generally treated as a blend of a recycled cast of characters, implicit different continuities being treated as obviously different, and it can be a pretty good idea to [[DeathIsCheap consider nobody dead in any of the series if the body has not been incinerated]].
* For the most part, ''Franchise/{{Digimon}}'' takes place in different continuities, which goes a long way towards side-stepping this whole issue. However, the Adventureverse has a few glaring inconsistencies, primarily relating to Ryo Akiyama's story. For one, the Omegamon movie contradicts the games themselves about where he was at the time (per D-1 Tamers, he was watching Diaboromon's acupuncture from Ken's place, whereas Our War Game had him as being outdoors in some mountainous region). Unrelatedly, Omegamon's formation-method also differs between versions (Fusion / Gattai in the sub, DNA in the dub).
* ''Franchise/LyricalNanoha'' is starting to run into this with two series of manga, ''Manga/MagicalGirlLyricalNanohaVivid'' and ''Manga/MagicalRecordLyricalNanohaForce'', running at the same time but taking place two years apart. They mostly manage to stay separate, but occasionally they contradict one another.
* ''Anime/TenchiMuyo'' used to be (in)famous for this, although compared to some of the other examples here it now seems fairly mild.
** The original anime, ''TenchiMuyoRyoOhki'', was a six episode OAV series by (then) Pioneer, later expanded by thirteen, which was largely the creative work of Masaki Kajishima.
** When Kajishima departed to work on other projects, Pioneer engaged Hiroshi Negishi to direct a TV series retelling of the story (released in English as ''TenchiUniverse''), with various contextual and character changes. This was followed by a feature film, ''Tenchi Muyo! In Love'', which was set in the same continuity. All pretty straightforward so far. However...
** To cash in on the popularity (and unresolved ending) of the [=OAVs=], Pioneer also green-lit a comedy-oriented special episode, known as the ''Mihoshi Special'', which was produced by some of Kajishima's creative assistants like Naoko Hasegawa, but without any input from Kajishima himself. This special is mainly influential for introducing ditzy space cop Mihoshi's long-suffering partner Kiyone (albeit purely in a backstory role). Kiyone would go on to appear in the aforementioned ''Tenchi Universe'' series.
** This was eventually followed by a feature film called ''Manatsu No Eve'' (Midsummer's Eve), also mainly the work of Naoko Hasegawa. This movie ''almost'' fits into the OAV and ''Mihoshi Special'' continuity, except that Kiyone appears as a regular character with no explanation. Pioneer further muddied the waters by releasing it in English as ''Tenchi the Movie 2: Daughter of Darkness'', leading some viewers to assume it was a follow-up to the previous movie, ''Tenchi Muyo! In Love'', which was actually part of a different continuity. Things were muddled even more when the ''actual'' sequel to ''Tenchi Muyo! In Love'', ''Tenchi Forever'' (''Tenchi Muyo! In Love 2'' in Japanese) came out a few years after that, and (obviously) didn't reflect any of the events of ''Daughter of Darkness / Manatsu No Eve''.
** Complicating matters even further was that Kajishima, who had plans to eventually return and finish the OAV storyline, despised both the ''Mihoshi Special'' and ''Manatsu No Eve'', and declared them CanonDiscontinuity. This was in part due to their use of 'Kiyone' as the name for a new character, whereas Kajishima had apparently already designated that as the name for Tenchi's late mother, who figured prominently in his future plans. To make things worse, Tenchi's mother had been given an entirely different name in the movie ''Tenchi Muyo! In Love'' (which took place in the ''Tenchi Universe'' continuity and had no connection to the OAV continuity).
** Having made his position clear, Kajishima came back and made a third set of OAV episodes to continue the ''Tenchi Muyo! Ryo Ohki'' continuity as ''he'' saw it (disregarding the ''Mihoshi Special'' and ''Manatsu no Eve'' entirely). In ''this'' continuity, Tenchi's mother is indeed named Kiyone, much to the confusion of people who had watched all of the previous continuities to date. (A fourth OAV series in the same continuity began coming out in 2016.)
** To sum up, the main Tenchi continuities discussed so far are:
*** Kajishima continuity (the first two OAV series, followed by the third and fourth), in which Kiyone is the name of Tenchi's late mother;
*** Hasegawa continuity, which essentially shares the first two OAV series, but branches off on its own with the ''Mihoshi Special'' and the second movie (''Daughter of Darkness / Manatsu no Eve''), in which Kiyone is the name of Mihoshi's former partner in the Galaxy Police;
*** Negishi continuity, which consists of the ''Tenchi Universe'' TV series, and the first (''Tenchi Muyo! In Love'') and third (''Tenchi Forever'') movies, but in which Kiyone is Mihoshi's ''current'' partner in the Galaxy Police, and Tenchi's late mother is named Achika.
** To keep this discussion at least moderately sane, the ''other'' alternate-continuity TV series (''Tenchi In Tokyo'') and the various manga continuities have been left out entirely, as they are reasonably self-contained and don't tend to splash over onto other continuities very much.
* ''Anime/TengenToppaGurrenLagann'' started off with a prologue involving Simon/Kamina/[[FanNickname Caption Garlocks]] ([[FanDumb fans argue this fact constantly]]) waging war against "All the lights in the sky." This is ''similar'' to battles late in the series, but never really fits any of them. The producers admitted that this was a fluke on their part, that it was meant to be ShoutOut to Arcadia, and that they never got around to building up to that scene in the main series. This had led fans to suggest that this scene is an [[WildMassGuessing alternate universe, a fantasy of]] [[TeamPet Boota]], [[WildMassGuessing an alternate timeline in which Kamina leads Dai-Gurren into space/Simon is sent back in time to battle the Anti-Spirals as well as become Kamina's father]].
* ''Manga/{{Kinnikuman}}'' has a rather bad example: when Geronimo attacks [[BigBad Akuma Shogun]], we see a group of choujin watching Geronimo's [[CurbStompBattle beat-down]], with ''Geronimo being in the group.'' In other words, Geronimo's watching himself get beaten.
* In the three Japanese-exclusive ''[[Franchise/TheTransformers Transformers]]'' anime series (''Anime/TransformersHeadmasters'', ''Anime/TransformersSuperGodMasterforce'', and ''Anime/TransformersVictory''), characters who died in ''WesternAnimation/TheTransformersTheMovie'' show up alive and well, as if nothing happened. This is because the movie wouldn't hit Japan until 1989, leaving many of its events unknown to the Japanese audience/creators. These characters are Prowl, who appears in ''Headmasters'', and Wheeljack, who appears in ''Victory''. Prowl is especially bad, since he was explicitly name-checked as being deceased in the Japanese dub of "Dark Awakening". Later fiction would handwave these appearances by explaining them as being versions of themselves from the ''Binaltech'' universe, taking the place of the originals who really did die during the movie.
* ''Manga/ViolenceJack'' being a true sequel to ''Manga/{{Devilman}}'' became a shaky thread over the years after ''Creator/GoNagai'' went on to create ''Manga/DevilmanLady'' and several other works that expanded its universe, ''Violence Jack'' came mere months after ''Devilman'' ended and Go Nagai bridged the connection to Devilman only a bit in the beginning and the at the very end, very loose connections to boot that Nagai didn’t bother to expand on, meanwhile ''Devilman Lady'' was made after Violence Jack and in that series Nagai made very solid connections to ''Devilman''. Go Nagai has also said that ''Violence Jack'' should be treated as its own universe, but that didn’t stop him from again making cryptic connections to ''Devilman'' in ''Shin Violence Jack''.
** Case in point: Violence Jack treats itself as a reboot universe created an unspecified time after the world ended in Devilman, [[spoiler:in this new world it’s revealed at the very end that Satan created the Slum King out of Zenon’s body to be his personal punisher, in mourning for what he did to Akira in the past, and Violence Jack himself turns into Devilman at the end to fight against Satan yet again]]. Come Devilman Lady and that series proposes a different following for Devilman, in it [[spoiler:Satan was reborn as two women on earth, Zenon was made the ruler of hell in Satan’s absence and Akira lived in hell all this time, he is only reborn again as the son of Jun the titular Devilman Lady]].
** ''Devilman Lady'' and ''Violence Jack'' contradict themselves, the only thing that can reconcile ''Violence Jack'' standing firm in the timeline is the revelation that Devilman’s world is on a constant loop thanks to God’s continuous punishment against Satan, so ''Violence Jack'' can be a separate loop.

[[folder:Films -- Live-Action]]
* The Franchise/{{Godzilla}} series has built up some impressively messy continuity over the decades.
** In ''Film/KingKongVsGodzilla'', Godzilla emerges from the iceberg he was trapped in during ''Film/GodzillaRaidsAgain.'' However, ''Raids Again'' was localized in America as a standalone monster flick called ''Gigantis The Fire Monster,'' so the dub for ''King Kong vs. Godzilla'' had to pretend that Godzilla had been trapped in the ice for millions of years and was just now getting out. However, everyone still knows about Godzilla and references him as though he's attacked before, due to the rest of the dialogue not being changed. As a result it's unclear as to whether the [[Film/{{Gojira}} original film]] happened or not in this continuity (and it's worth mentioning that the [[Film/GodzillaKingOfTheMonsters1956 American version]] of the original already established a different continuity than its Japanese counterpart, introducing a new character)
** Throughout the 1960s, several of Toho's other giant monster films were retroactively included in the Godzilla universe, regardless of continuity issues. For example, Godzilla coexists with a monster named Gorosaurus, who originated in ''Film/KingKongEscapes,'' which depicts King Kong's discovery and abilities in a way that's absolutely irreconcilable with what was shown in ''King Kong vs. Godzilla''. Baragon, from ''Film/FrankensteinConquersTheWorld'' also made his way into the series, so we have the Frankenstein monster out there in this universe as well. There are indications that this is meant to be the same monster seen in the Franchise/UniversalHorror films of the 30s and 40s, so do Dracula and the Wolf Man also exist in this world? Maybe.
** ''Film/AllMonstersAttack'' has a questionable place in the series' continuity due to Godzilla and the other monsters only appearing in the day dreams of a young boy named Ichiro. Is this supposed to be in the same universe as the other movies, or is it in the "real world" and Ichiro just likes Godzilla movies? None of the other films directly reference this one, but it did introduce Monster Island, which became important later on, so the mystery is unsolved.
** The series was rebooted in 1984 with ''Film/TheReturnOfGodzilla,'' which accepts the original film but ignores all of its sequels. Amusingly, this film's American release is actually a sequel to the American release of the original, featuring the same Western-exclusive character returning. He doesn't show up again in the American cuts of any of the other movies from the 1984-95 series, making it unclear which version of the original and ''Return'' they're meant to follow.
** ''Film/{{Godzilla 1998}}'' was a remake of the original, unconnected to all the others.
** ''Film/{{Godzilla 2000}}'' kicked off the "Millennium Series" of films. It takes place in its own universe. Its follow-up, ''Film/GodzillaVsMegaguirus,'' features the same Godzilla suit but takes place in ''another'' continuity where only the original film happened, but with a completely different ending than the "canon" one.
** The next film, ''Film/GodzillaMothraKingGhidorahGiantMonstersAllOutAttack'' is in yet another continuity in which the original film and, somehow, ''the 1998 film'' both took place, but none of the others.
** After that, ''Film/GodzillaAgainstMechagodzilla'' started ''another'' continuity where the original film happened but again with a different ending (and ''not'' the same ending ''Megaguirus'' featured) as well as several other Toho Monster films, but only ones not featuring Godzilla. Things get messy because one of those films, ''Gorath,'' featured the destruction of Earth's moon, which is clearly still visible.
** ''Film/GodzillaFinalWars'' and ''Film/{{Godzilla 2014}}'' are each set in their own brand-new continuity with no connection to anything else. The ''Final Wars'' continuity, though, seems to have had BroadStrokes versions of the original 60s-70s movies occur in its backstory.
* ''Film/SilentHillRevelation3D'' is absolutely full of this with regards to the first film, despite being an integrally-linked sequel. This was the result of the writer's attempt to make the sequel more faithful to the video game's storyline.
** In the first movie, Sharon is 9 years old. ''Revelation'' is explicitly set 6 years later, yet in that film she's just about to turn 18.
** In the first film, it's clearly stated (and made obvious by some plot events) that "Only the Dark One [[spoiler:(Dark Alessa)]] opens and closes the door to Silent Hill." Yet in the sequel, a minor character says she became trapped in Silent Hill's otherworld simply by taking a wrong turn and getting lost in a fog bank, when there was no reason for "the Dark One" to bring her there.
** The biggest is probably that the first movie's climax includes [[spoiler:Dark Alessa and Sharon, the two halves of Alessa's soul, merging back into a full reincarnation of Alessa]]. Yet in the sequel, [[spoiler:Sharon is still only one half of Alessa, Dark Alessa is still back in Silent Hill, and there's another big scene right before the climax where they merge... again]].
** In the first movie, it's revealed that Alessa [[spoiler:was burned by the town's pseudo-Christian cult on suspicion of being a witch, and that the cult members believed burning her would stop the apocalypse]]. In ''Revelation'', it's explained [[spoiler:the town's clearly pagan cult, the Order of Valtiel - which is oddly described as the same cult from the first film - burned Alessa because she was a chosen one who had to be ritually burned in order to CAUSE the apocalypse of this world and bring about the rebirth of their god and the creation of a new paradise]]. Paradoxically, [[spoiler:''Revelation'' still contains flashback scenes of schoolchildren tormenting Alessa for being a witch]].
** In the first movie, the motive of [[spoiler:Alessa, in her creation of Sharon,]] was to [[spoiler:send Sharon out as an orphan, get her a loving, protective mother, and then call her back to Silent Hill to lure in the mother so that she could be persuaded to assist in Alessa's revenge against the cult for the sake of her adopted daughter]]. In the sequel, it's instead stated by [[spoiler:Dark Alessa that Sharon was created just to live outside of Silent Hill and have a happy, normal life, and that Alessa never wanted Sharon to ever return because it would help the cult]]. Since this is the exact opposite of her plan in the first film, it seems she [[spoiler:never called Sharon to Silent Hill during the time of the first movie]], yet no other explanation is ever given as to why [[spoiler:Rose and Sharon went to Silent Hill six years before ''Revelation''.]] Since that needs to happen to set the sequel's plot in motion, ''Revelation'' essentially writes itself out of existence without realizing it.
* Minor by comparison to most of the other examples, but Tim Burton's ''Film/{{Batman}}'' featured a black Harvey Dent, whereas when he was used as a character in the Joel Schumacher-directed sequels, he was depicted as white. Or at least, [[TwoFaced half of him is white]].
* ''Franchise/{{Highlander}}'' is one of the kings of this trope. Each of the original films screwed up the continuity more and more (and two of them are CanonDiscontinuity in any case), and then the series was added in and then there are things like Search For Vengeance, and the Animated Series. This is another universe that will give you a headache if you try to figure it out.
** It's general accepted the original movies with Connor (save for [=HL2=]) are a separate timeline from The Series.
* ''Film/MenInBlack'' has Agent K erasing the data on James Darrell Edwards, the future Agent J, including a birth certificate dated 1975. [[spoiler:The third movie takes place in 1969, and a young J is featured. The confusion is made worse by Creator/WillSmith [[AgeLift being born in 1968]].]]
* The ''Franchise/StarWars'' saga caused several snarls, with some caused due to conflicting Expanded Universe material, and some due to the series' jump from the original trilogy to the prequels:
** When {{Creator/Disney}} acquired the franchise, the previously existing EU material was relegated to a separate "Franchise/StarWarsLegends" continuity in order to avoid some of this with the sequel trilogy.
** Obi-Wan has several statements in the OT that turn out to be [[MetaphoricallyTrue Half-Truth]] at best (which does fit in with his character; he is one of the most prominent examples of Half-Truth). He claimed he didn't own a droid in ''Film/ANewHope'', but did during the prequels (though apparently it was the Jedi Order's droid, not his personal droid). He apparently didn't know that Leia was Luke's sister at first, despite being present when they were both born and named. He never specifically stated that Yoda was his mentor, but it was certainly the implication in ''Film/TheEmpireStrikesBack'' (before it's revealed that it was Qui-Gon Jinn, then subsequently patched up by showing Yoda trained young Jedi before they grow up and get another mentor as a Padawan). It is lampshaded in the Episode VI, when Luke asks to Obi-wan why he didn't tell the truth about his father having become Darth Vader instead of the story he was killed by him. The old Jedi explains that the one that Anakin used to be died metaphorically once he joined the dark side, so what he said was true, [[MetaphoricallyTrue from a certain point of view]].
** Leia claimed to have remembered her mother in ''Film/ReturnOfTheJedi'', but Padme died in childbirth in ''Film/RevengeOfTheSith''. Possibly explainable if she was thinking about her adopted mother Breha Organa, although Luke does specify "your real mother" when he asks, what implies Leia had a first adoptive mother or a nanny before Breha that she mistook for her true late mother. The novelization of ''Film/RevengeOfTheSith'' lampshades/handwaves this. When the twins are born Luke is described as having his eyes shut tightly while Leia's are open as if trying to take in everything. Presumably, [[AWizardDidIt the Force then allows Leia to remember Padmé even though newborns don't have a working long-term memory]]. It's later addressed in Marvel's ''ComicBook/PrincessLeia'' series, where she has a Force vision of Padme while visiting Naboo, realizing at once that the former queen is her mother.
** In ''Film/TheEmpireStrikesBack'', Darth Vader does not seem to recognize C-3PO, despite creating him in ''Film/ThePhantomMenace'' (and remarking in said film that he's incredibly unique). The Expanded Universe attempted to rectify this in a (non-canon) story called "[[http://starwars.wikia.com/wiki/Thank_the_Maker Thank The Maker]]", where Vader reminisces about his mother and 3PO when he's at Cloud City. Of course, at a glance he looks like every other member of a fairly ubiquitous model line.
** ''Film/RevengeOfTheSith'' reveals that it took roughly 20 years to build the Death Star (from the time Luke and Leia are born, a rough frame of the structure is being built) without anyone realizing it. In ''Film/ReturnOfTheJedi'', the Death Star II only takes 3-4 years to be fully functional and mostly-built. The [[ExactlyWhatItSaysOnTheTin apty-named]] novel "Death Star" tries to address this, going over numerous problems that came up over the course of its construction (including at least one instance of the superlaser having to be stripped out and redesigned). Death Star II, despite being somewhere between 2 and 20 times larger than Death Star I (depending on the source), could be built much more quickly because by that point the Empire actually ''knew how to build a Death Star''. Gets a possibly unintended lampshade when an Imperial officer complains about the speed at which he's expected to finish the project. Making it worse is that in the original Expanded Universe (written before the prequels) there was a prototype built in the secret Maw Installation (having nothing to do with the Geonosians) before work on Death Star I ever started. It's later established in ''Film/RogueOne'' that Galen Erso deliberately dragged out the process for as long as he could, and [[spoiler: included that infamous exhaust port in the design]].
** Obi-Wan and Yoda supposedly left Luke on Tatooine with the purpose of training him later. When that day came, Yoda acted surprised and even argued with Obi-Wan as to whether or not Luke should be trained. While in the prequels, Yoda is explicitly shown teaching young children (and therefore may simply have assumed the plan had changed since Luke wasn't brought to him, say, ten years ago and feel that Luke is now too old to begin training), which suggests that he's upset because Obi-Wan (who was literally watching over Luke his entire life) didn't train him as he was expected to.
** Within the original trilogy, Luke and Leia are set up as possible love interests (to the point that a deleted scene shows them about to kiss), only to be revealed as siblings later on. Neither of them ''has the slightest idea'' that they are, even though Luke's Force perception should have tipped him off at some point. The problem was that Han Solo clearly has a romantic interest in Leia in ''Empire Strikes Back'', and the last thing old-school George Lucas wanted was to end the trilogy with a messy love triangle.
** Obi-Wan, and Anakin after he removes the Vader mask in ''ROTJ'', are played by actors in their 60s and 70s, respectively, suggesting they would have been in their 40s and 50s when Luke and Leia were born. Instead, they were shown to be in their 20s and 30s. Possibly justified: With Vader, he was terribly scarred and had to resort to Bacta Tank baths in order to heal his burned skin, thus making him seem older then he looks. In the case of Obi-Wan, him being YoungerThanHeLooks could be explained as due to living alone on a Tatooine for 20 years as well as the stress of [[TraumaCongaLine everything he has endured throughout his life]] taking its toll on him physically.
*** Obi-Wan ''was'' roughly as old as Alec Guiness as of Episode IV, though: He was born in 57 BBY according to canon, which makes him only 5 years younger than his actor. The confusion presumably comes from Ewan McGregor being 30 years younger at the time of III than Alec Guiness was at the time of IV, i.e. him being 5 years ''younger'' than "his" version of Obi-Wan.
** Anyone who listens to the Radio/StarWarsRadioDramas can't help but notice that Han shoots first and Han does not meet Jabba on Tatooine. These were two of the more infamous changes made by Lucas when he ReCut the 1977 film for re-release.
** ''WesternAnimation/StarWarsTheCloneWars'' caused a few continuity snarls, but the biggest was probably Wulff Yularen, a character who briefly appeared in the first movie as an [[StateSec Imperial Security Bureau]] colonel. The animators mistook him for a high-ranking Navy officer and made him an admiral during the Clone Wars. This led to an escalating series of {{retcon}}s, as each attempt to reconcile his background [[VoodooShark created a new plothole somewhere else]].
* The original ''Franchise/RoboCop'' trilogy has a bit of a minor problem with the name of the titular cyborg's superior officer, Sgt. Reed: in [[Film/RoboCop1987 in the first movie]], his first name is given in one scene as "John", but in [[Film/RoboCop2 the second]], he's referred to by Murphy (following his reprogramming by Dr. Faxx) as "Warren".
* The ''Film/SinCity'' films feature a series of stories in the same setting. The first film establishes that Marvin dies at the behest of Senator Roarke, but a story in the second film has Marvin still alive when Roarke is killed.
* Thanks to its continuous abuse of RuleOfCool, as well as its blatant assumption that every viewer is familiar with the books, it can be a right mess trying to determine just how magic functions in ''Film/HarryPotter''. Even before non-verbal magic is introduced sometimes Harry and friends need to say the spells out loud and sometimes they don't, sometimes Expelliarmus disarms and sometimes it hurls the target across the room with the force of a cannon, sometimes apparition leaves a smoke trail and sometimes it doesn't, sometimes wizards need a wand to cast spells and sometimes they don't, spells that have inconstant effects so that the exact same incantation can produce a beam/flash/bolt/crackle without explanation... there really are far too many examples to reasonably list here. The set changes are also a problem. Whilst we can possibly excuse Hogwarts looking different with every film as the special effects and budget improves, things like Hagrid's hut shifting position, size, shape and materials go unexplained.
* In ''Film/HaloNightfall'', one of the given reasons for going to the Alpha Shard is to find proof that "the Covenant's broken the treaty". The issue is not only that the Covenant has long been split into multiple opposing factions by this point, but that a number of these factions are already openly vocal about their hostility to humanity: the entire plot of ''VideoGame/HaloSpartanAssault'' was about a Covenant remnant attack on a UNSC colony that happened about two years ''before Nightfall''.
* Most of the films which Creator/QuentinTarantino had a hand in creating are part of one of two sprawling cinematic universes, the "Realer than Real Universe," and the "Movie Movie Universe," which consists of films that are meant to exist within the Realer than Real Universe. Sounds simple on paper, but the exact continuity is very messy when you look at the details. Officer Earl [=McGraw=] and his son Edgar show up in ''Film/DeathProof,'' which is part of the Realer than Real Universe, but Earl also shows up (and ''dies'') in ''Film/FromDuskTillDawn,'' and both [=McGraws=] show up in ''Film/KillBill,'' both of which are in the Movie Movie Universe. So, it's possible that the characters in the Movie Movies are meant to be based on the real [=McGraws=] in the Realer than Reals, but the real problem comes from ''Film/PlanetTerror'', which seems to takes place in the same universe as ''Death Proof'' (the two share several locations and characters) and yet those two movies don't mesh since ''Planet Terror'' depicts a zombie apocalypse and the second half of ''Death Proof'' would take place after this, yet there's no sign of zombies anywhere. So, does ''Planet Terror'' fit into the Movie Movie Universe and the whole cast of ''Death Proof'' exist in both universes the way the [=McGraws=] do, or does ''Planet Terror'' somehow exist in the Realer than Real universe and nobody happens to ever mention that one time zombies nearly took over the world? No matter how you try to piece it together, it doesn't make sense...though that's likely the joke, given that ''Planet Terror'' and ''Death Proof'' are both parodies of terrible old grindhouse movies which didn't care about continuity either.
** The ''Film/{{Machete}}'' trilogy is also possibly a part of the Movie Movie Universe, which complicates matters further because the title character of those films is officially the same person as Uncle Machete from the ''Film/SpyKids'' series. Are ''those'' part of the Movie Movie Universe too? We'll likely never get a straight answer.
* In ''Film/TheMummyReturns'' Rick and Evie have an 8 year old son named Alex. The first movie takes place mostly in 1926, while the second takes place in 1933. 1933 is 7 years after 1926, Alex being 8 is problematic for time.
* ''Film/{{Serenity}}'' has a few in its adaptation from ''Series/{{Firefly}}'', possibly to make an all-inclusive story that wouldn't confuse people who hadn't seen the show. In the show, Simon Tam hires people to rescue River for him, not only because he's not a suave action guy, but because the authorities already are aware of him due to one previous rescue attempt. In the movie, he sneaks in with a false identity like a secret agent. He's also fully aware of her psychic abilities in the movie, but in the show he acts willfully ignorant of them, and an episode is devoted to him trying to figure out what's wrong with River. Also, in that particular episode, he discovers that the reason River acts insane is that ''part of her brain has been removed'', but in the movie she's just experiencing a temporary insanity due to carrying a terrible secret, and is cured once the secret has been revealed. There are other minor variations, like the show depicting the Alliance as apathetic at best, horribly corrupt at worse, but the film says their problem is that they are trying to be benevolent at the cost of individual rights.
* The official prequel comic for the first ''Film/GuardiansOfTheGalaxy'' movie revealed that Nebula had cut off her own arm [[LifeOrLimbDecision to escape a trap]] after being ensnared by Gamora. ''Film/GuardiansOfTheGalaxyVol2'' instead says that Comicbook/{{Thanos}} had Nebula's arm amputated and replaced with a cybernetic upgrade after she lost a fight to Gamora. Creator/JamesGunn ended up having to declare the prequel non-canon to explain the discrepancy.

[[folder:Legends and Folklore]]
* UrbanLegends falls under this trope, being a form of present-day OralTradition, they often change via GossipEvolution with every retelling.
* Arthurian Legends:
** Who is Myth/KingArthur's greatest knight: Sir Gawain, Sir Lancelot, Sir Percival, Sir Galahad, or King Pellinore? Did you even know that in many of the earliest tales, it is Sir Gawain, without question? And before that, it was ''Mordred as a good guy''.
*** And what about Sir Griflet? Originally one of Arthur's most loyal knights, he was pretty much supplanted by Sir Bedivere.
*** And Lancelot, the one knight that everyone knows, isn't even part of the "original cast". He was originally the star of his own set of adventures and only got mixed in with the other knights along the way.
*** According to Creator/PeterDavid, Lancelot was "the first Mary Sue." This certainly explains his (or rather his reincarnation's) treatment in Knight Life.
*** In the very earliest stratum [[OneManArmy Cai]] was ''easily'' the foremost of Arthur's war band.
** And Morgan Le Fey -- once she made the CrossOver and stuck, having originally been from the Matter of France -- went from being a benevolent sorceress who had saved Arthur's life on multiple occasions to a vindictive {{yandere}} bent on breaking up Arthur/Guinevere to the mother of the BigBad to the BigBad herself. And even after Mordred was {{retcon}}ned into being her son, he originally wasn't fathered by Arthur. And then the whole BrotherSisterIncest thing got added in.
** How exactly are Arthur and Mordred related? Is Mordred Arthur's [[EvilNephew nephew]], his [[AntagonisticOffspring son]], [[TakeAThirdOption or]] [[BrotherSisterIncest both]]?
** Another sticking point is whether Excalibur is the same as the Sword in the Stone, or if they are two different swords.
** Then there's Elaine of Astolat AKA the Lady of Shalott. Half the time she's an innocent maiden who falls in love with Lancelot and then dies of heartbreak. The other half she's still a maiden who falls in love with Lancelot, but instead of being innocent she forces herself of Lancelot with the help of magic and then bears his son.

* ''The Briar Creek Vampires'': In one book, it is a major plot point that vampires do not simply burn up or turn to dust, but leave behind normal bodies that must be disposed of. In later books, they turn to dust every time.
* Because he was constantly revising his unpublished works, Creator/JRRTolkien (1892-1973) managed to create a Continuity Snarl ''all by himself'' (which is probably why they were unpublished). His son Christopher edited many of them together into ''Literature/TheSilmarillion'', trying his best to come up with a version that didn't contradict itself and presenting it as in-universe folklore to cover remaining holes.
* Another devout Catholic fantasy author (1892-1973) had similar problems with ''his'' massive fantasy opus about small people who save their world from evil. It's possible that Creator/HenryDarger had so many characters with similar (or the same) names simply because he forgot that he'd [[OneSteveLimit already used that name]] back in ''Literature/InTheRealmsOfTheUnreal'' Book CLXVII 2.0.
* The Literature/LandOfOz suffered from continuity problems from Creator/LFrankBaum's hands. This included whether they used money, whether they could die, and where Ozma came from.
** He managed to get a Continuity Snarl with two books. In the first book, the Scarecrow is OfferedTheCrown of the Emerald City--Glinda has the flying monkeys carry him back there so he can claim it. In the second book, when the Scarecrow goes back to Glinda for help regaining his crown, she tells him that he's not entitled to it, it's Ozma's.
** The fate of the Winged Monkeys themselves is a smaller case of this. In the first book, the Golden Cap can only be used to command the Monkeys three times per person, and when Glinda gets a hold of it, she explains exactly what she'll use it for (specifically, to send Dorothy's three companions to their new homes), and then says she'll give the cap to the leader of the Monkeys, freeing them. In the second book, The Scarecrow says that Glinda still has the Golden Cap, and the Winged Monkeys are now her permanent slaves.
** Heck, as Oz went on, the number of adaptations, prequels, sequels, spinoffs, side-stories, etc have made it even worse. In fact, take [[http://en.wikipedia.org/wiki/List_of_Oz_books one look]] at the number of books ''alone'' that take place in an alternate continuity, and which ones are considered "Canon".
* Creator/HPLovecraft's Franchise/CthulhuMythos. Lovecraft himself was not always very consistent with various details between his stories, and several of the other authors who continued his work had various contradicting views of the mythos, leading to much confusion for anybody trying to fit all the stories into a single continuity.\\
Part of the reason behind that is that, at the time, Lovecraft had a very "pulp fiction" attitude towards his stories - not only did he have very little intent to create a cohesive continuity framework into which all of his stories could be inserted, but he tended to see each story as somewhat self-sufficient and exclusive. Mentioning the same occult book in multiple stories or inserting a reference to a character from another story was more a method to create the feeling of [[CrypticBackgroundReference artificial depth]] to the story at hand rather than trying to imply they all took place in a consistent universe. Lovecraft never really bothered to maintain continuity in his OWN stories, let alone all the stories written by his friends and associates that used shared references. \\
Furthermore, Lovecraft aimed to create the feel of ancient myths by adding in deliberate inconsistencies, depending on what source the characters of a particular story gain their information. There's at least three different species as candidates for the title of the Great Old Ones, for example, as well as the more famous interpretation which Derleth embraced that the name refers to unique creatures of immense power.
** Given that the Cthulhu Mythos is full of bizarre things that defy human comprehension, [[FridgeBrilliance the continuity confusion is weirdly appropriate]].
* The Franchise/StarWarsExpandedUniverse is so large almost no fans have read even most of it. The lack of clarity on what is and isn't canon (and [[DeathOfTheAuthor the constant refusal to listen to]] WordOfGod) doesn't help either.
** One of the simpler examples of this snarling; if you take the Original Trilogy and the EU as a whole, then it seems like Boba Fett manages to fall into the Sarlacc no less than ''three times'': both the novel ''Literature/TalesOfTheBountyHunters'' and the comic "Boba Fett and the Jawas of Doom" start with Boba escaping from the Sarlacc's guts, but with completely different results. In the former, Boba is found and nursed back to help by Dengarr[[note]]the slovenly-looking human bounty hunter with a headwrap in the lineup from ''The Empire Strikes Back''[[/note]], while in the latter, he is found and temporarily enslaved by Jawas, only to end up plunging back into the Sarlacc's mouth again at the comic's end.
* Literature/{{Discworld}} suffers somewhat from this, but it is [[JustifiedTrope explained in-universe]] as the results of [[TimeCrash Time shattering]] and having to be stitched back together by the [[Discworld/ThiefOfTime History Monks]]. '' Twice''. They only get away with it because of the extraordinary power of the human mind to deceive itself.
** An in-universe example happens in ''Discworld/{{Pyramids}}'', where it's mentioned that Djellibeybi's mythology has been changing so thoroughly over the years, several concepts and objects have multiple gods and stories that explain them, each of them contradicting each other. The sun ''alone'' has several gods who are supposed to move it around. The High Priest is the only one that can keep them straight, mostly through prodigious Doublethink that lets him believe each mythological continuity simultaneously while being aware they can't exactly mesh. [[spoiler:And when all of these mythologies come to life when [[RealityIsOutToLunch reality goes on a Pyramid-assisted lunch break]], they cannot keep the stories straight either, and agree to decide who's real through an all-out brawl, complete with announcer]]
** The History Monks have apparently pushed the invention of the clacks back a bit. It originally appears in ''Discworld/TheFifthElephant'' as an exciting new invention. The book ends with Lady Sybil announcing her pregnancy to Sam. But in ''Discworld/GoingPostal'', the twenty-ish daughter of the inventor talks about the early success of the family business as though it happened when she was a child. And ''Discworld/{{Thud}}'' must be set after that, since it refers to stamps, but Young Sam is still learning to talk. Then ''Discworld/RaisingSteam'' has Adora Belle reminiscing about being in clacks towers when she was a ''baby'', even though this book takes place "a scant while" after ''Discworld/{{Snuff}}'', in which Young Sam is ''six''.
* In his later years, Kir Bulychyov admitted that he never reread any books in his ''[[Literature/AliceGirlFromTheFuture Adventures of Alisa]]'' cycle, which would explain the many, many continuity problems that emerged over time. Krys, a recurring villain, had about three different (contradictory) origins and six different explanations of how his powers worked. His companion, Veselchak U, gained and lost powers. The chronology has been anything but consistent and don't even get started on when half of the novels were supposed to take place relative to each other. The fact that Kir Bulychyov died a few years ago doesn't help at all.
* Chris Roberson aims for this on purpose--as a kid, he loved reading comic books and seeing all the ways they interconnected. Pretty much everything he writes that isn't a tie-in to ''TabletopGame/{{Warhammer 40000}}'' is in a single setting, but he explicitly uses the "many worlds" model of quantum mechanics, and [[ForWantOfANail slight deviations lead to massive differences over a relatively short period of time]]. Attempting to fit his works into a single continuity would be arguably meaningless, and it's uncertain whether even he knows what he's doing half the time.
* An entire cottage industry has sprung up around trying to wrestle the Sherlock Holmes stories into continuity -- not only with each other, but with actual history.
** They [[FanNickname call themselves]] the [[http://en.wikipedia.org/wiki/Baker_Street_Irregulars Baker Street Irregulars]] after the street urchins Holmes often calls upon for help. Basically, their version of [[Franchise/StarTrek Trekkies]].
* The ''Franchise/SonicTheHedgehog'' mini-novels made by Michael Teitelbaum and Ron Zalme; the novels clearly take place in the [[WesternAnimation/SonicSatAM SatAM]] universe, yet the Robotnik used in it is the one from ''WesternAnimation/AdventuresOfSonicTheHedgehog''. How ''that'' fits into continuity is anyone's guess.
* The author of the first three ''ComicBook/{{Bionicle}}'' books was probably only instructed to keep the books close to the comic series and ignore other sources. This lead to the events presented in online material (which at the time of the books' writing had a dubious place in canon), as well as the canceled PC game becoming irreconcilable with the book's plot. A lot of scenes also differ in their presentation from the source material, like how the Toa received their Golden Masks, and the entire final battle with the Manas and Makuta, the latter of which ''doesn't occur'' in the book, despite being the GrandFinale of that story arc. Many scenes are written in a way that makes the book unwarrantable for a CompressedAdaptation title, since the left-out events cannot be spliced in between the chapters. These could be forgiven, were the book meant to be a simple adaptation, or a "new take" on the story, but it was supposedly intended to be part of the official timeline.
* In ''Literature/TheBookOfNightWithMoon'' Tom and Carl are stated as Advisories, which would put it before the second book in the other series. Then Nita shows up... and says that Dairine has passed Ordeal, which is the plot of the ''third'' book!
* ''Literature/RangersApprentice'' has problems with its continuity, possibly because WritersCannotDoMath. Every major event in Halt's life -- leaving home, coming to Araluen, becoming a ranger -- happened "twenty years ago"; in the first book this isn't a problem, because it would've been about twenty years exactly from when it started to then, but all this still happened "twenty years ago" after ''five or six in-universe years''. Possibly justified with Halt just rounding it off, because "twenty years ago" is easier to say than "twenty-five years ago".
* A couple of them in ''Literature/TwilightSparkleAndTheCrystalHeartSpell'':
** The book either ignores or undoes Trixie's redemption in ''[[Recap/MyLittlePonyFriendshipIsMagicS3E5MagicDuel Magic Duel]]''.
** The lines "The last time they'd all visited was during the [[Recap/MyLittlePonyFriendshipIsMagicS3E1TheCrystalEmpirePart1 Crystal]] [[Recap/MyLittlePonyFriendshipIsMagicS3E2TheCrystalEmpirePart2 Faire.]]" ignores the SynchronousEpisodes ''[[Recap/MyLittlePonyFriendshipIsMagicS3E8JustForSidekicks Just for Sidekicks]]'' and ''[[Recap/MyLittlePonyFriendshipIsMagicS3E12GamesPoniesPlay Games Ponies Play]]''.
* ''Literature/WarriorCats'':
** In ''The Fourth Apprentice'', Yellowfang witnesses Breezepelt and Brokenstar attacking Jayfeather and tells him that the Dark Forest is rising. In ''Fading Echoes'', a book written by a different author, Jayfeather tells her about the attack and the uprising within the Dark Forest and she is shocked and apparently doesn't know anything about what he's talking about. Ummm...
** In ''Secrets of the Clans'', Raggedstar is the leader when his son, Brokenstar, is born. However, in ''Bluestar's Prophecy'' and ''Yellowfang's Secret'', he is deputy. (Although in the scene in ''Yellowfang's Secret'' where she gives Brokenkit to Lizardstripe, there's a few accidental mentions of his leader name; the scene appears to have been copy-pasted from ''Secrets of the Clans'' and edited.)
** The short story "The Elders' Concern", from the official ''Warriors'' app. The story is about how the elders are discussing how they're not happy with Fireheart as deputy, because he's young and not Clanborn and was named after moonhigh... except in this story, he's named deputy immediately after Lionheart; it takes place the day after Lionheart's death. Also, they're unhappy that Tigerclaw wasn't chosen, because he's the best fighter. Uh, Fireheart was an apprentice when Lionheart died. And how could they forget about the BigBad Tigerclaw becoming deputy after Lionheart and his subsequent attempts to kill Bluestar in order to become leader?
** Firestar's [[CatsHaveNineLives nine lives]] is probably the most major one. He first lost a life in ''The Darkest Hour'' to Scourge, and then ''Dawn'' to the falling tree; at the beginning of ''Sunset'', it said he had seven lives left, and then at the end after he's caught in the fox trap and is noted to be lying motionless, it says he has six left. Then ''Firestar's Quest'' came out - which takes place after ''The Darkest Hour'' and before ''Dawn'' - which said that he had ''six'' lives left, and then he lost one to rats in the book. When asked why it said six, Vicky said that he lost one to Scourge, one to the rats in the book (even though the line was before it occurred), and one helping Ravenpaw (the Ravenpaw manga was not released until years later, and when it was released, it took place after Firestar's Quest and he didn't lose a life in it), so that didn't clear up matters at all and just caused confusion; the "six" line is generally assumed to be an error. Vicky also said that he didn't lose one in the fox trap (and the short story "After Sunset: The Right Choice?" would later support this), despite ''Sunset'' itself claiming he had. He lost one in Long Shadows to greencough, and one just before The Fourth Apprentice to a fox. In Fading Echoes, Yellowfang says that five of Firestar's lives are in [=StarClan=], leaving him with four remaining. If you count all the lives we actually ''saw'' him lose in the books minus the fox-trap one - Scourge, rats, tree, greencough, fox - this is correct. He lost a life at the end of Fading Echoes to Russetfur, evidently leaving him with three left. And then he lost a life - his ''final'' life - in The Last Hope to wounds from the Dark Forest battle. The only way that this count is accurate is if you count the fox trap (which one book said did happen, and Word of God and one short story said it didn't), and the supposed "Ravenpaw" one which didn't actually happen in the manga nor was referenced whatsoever in the books, or perhaps just headcanon that his wounds in ''The Last Hope'' were bad enough to take more than one life. No matter which book directly references his life count, it's always incorrect each time.

[[folder:Live-Action TV]]
* ''Series/IDreamOfJeannie'' was infamous for this. Notably, in the first series, it was explained that Jeannie had been a mortal girl who was turned into a genie (and trapped in a bottle) by an evil djinn who fell in love with her. Starting in the second series, Jeannie was born a genie, and all of her relatives were genies as well, notably her evil sister.
** A series one episode featured Jeannie losing a potential career as an actress when it was revealed that she could not be filmed. Many later episodes forgot about this, with one episode featuring Jeannie getting targeted by thieves after appearing with an ancient jewel in a photo, and another episode featuring a scandal when Jeannie and Tony are photographed together. The Wedding episode bizarrely brought back the idea, where complications arose when Jeannie got not be photographed for her wedding.
** Finally, what would happen if Jeannie and Tony got married. In an early episode, it is said that Jeannie would lose her powers if she married a human, but her children could still be genies. When they actually married in the show, Jeannie still kept her powers.
*** On the issue of the children, in the TV movies, it was originally shown that Jeannie's son did inherit his powers, but the second movie portrayed him as a mortal.
* ''Series/{{Smallville}}'':
** Moira Sullivan, mother of Chloe Sullivan, is nothing more than a walking Continuity Snarl. Her past varies slightly every time in her few appearances, the difference usually including the time when she left Chloe.
** When Creator/ChristopherReeve died, it was decided the RecurringCharacter [[RemakeCameo he played]], Dr. Virgil Swann, [[TheCharacterDiedWithHim had died with him]] and Swann's death was revealed in a mid-Season Four episode. Three years later. Swann's daughter showed up and claimed [[RetCon her father had actually been poisoned by Lionel Luthor.]] The problem is that early in Season Four, Lionel had gone through a [[HeelFaceTurn conversion period into a sincere good guy.]] He was even a bit of a goody-two-shoes. While this "goody-two-shoes" phase didn't last, it started long before the episode that revealed Swann's death, and didn't end till shortly afterwards (and the same episode that revealed Swann's death also established he'd been alive a week earlier). It doesn't seem likely Lionel would've had Swann killed during this period.
* While ''Series/TheThickOfIt'' maintains unusually high amounts of continuity for a BritCom, details of Malcolm Tucker's homelife are somewhat inconsistent. ''Spinners and Losers'' reveals he has a niece, but Series 3 shows him spending his birthday alone in his office. The SeriesFinale, in addition, has him state he has no children, which is potentially contradicted that ''same episode'', when a young boy is seen looking out of the window of his home.
* ''Series/DoctorWho'':
** The most notorious example of this is the "UNIT dating controversy" (yes, we've heard all the slash fiction jokes). At the time that the early-1970s main run of UNIT stories featuring the Third and Fourth Doctors was made, the intention on the part of most of the creators was that they were set TwentyMinutesIntoTheFuture, with a more active space programme and slightly higher tech generally, although no attempt was made to alter fashion and vehicles. There were few actual in-canon references -- the most explicit one is Sarah's claim in "Pyramids of Mars" to come from 1980. However, the later story "Mawdryn Undead" explicitly states that the Brigadier retired before 1977, suggesting that the earlier stories were set at broadcast date. Fans learnt to shudder when the topic of what exact decade(s) the UNIT stories were set in is raised, before the new series demonstrated how much worse it could get. Precisely when the UNIT stories were set may be unclear, but at least we know which order they took place in. The revived show established that even The Doctor is unsure on this point.
** With the new series and {{spin off}}s, we don't even know that. Most of this confusion is due to Rose "losing" a year in "Aliens of London", putting most of the first season's contemporary stories in 2006, a year after broadcast. However, despite being consistent with this for the first couple of years, by Series 4, ''Series/{{Torchwood}}'' and ''Series/TheSarahJaneAdventures'', they began using the same year as production, even though they were mentioning past events that should have happened ''next'' year.
*** When Creator/RussellTDavies stepped down as showrunner for ''Doctor Who'' one of the last things he did was to undo this "year ahead" scenario by setting the Tenth Doctor's final story in the same year as its broadcast. Later, however, the 2014 episode "In the Forest of the Night" established a two-years-ahead timeframe for modern-day episodes, which was almost immediately ignored by succeeding episodes and spin-off media.
** There are sound arguments that ''[[Series/TheSarahJaneAdventures Revenge of the Slitheen]]'' happened after "Smith and Jones", and equally sound arguments it happened first. Evidence that "Revenge of the Slitheen" comes second include a mention in the previous episode (chronologically a week earlier) that it takes place eighteen months after the events of "School Reunion" and the plot of "Revenge" seeming to take place at the beginning of the school year. However, "Turn Left" has the cast of Series 1 of ''Series/TheSarahJaneAdventures'' enter the plot of "Smith and Jones" which seems to take place -at the latest- in May due to ''Series/DoctorWho'' series 3 having a plot point revolving around an election (British elections take place in May).
** The Eighth Doctor's continuity doesn't even try to make sense simultaneously. His only definitively canon stories are his birth in [[Recap/DoctorWhoTVMTheTVMovie the telemovie]] and his death in "[[Recap/DoctorWho50thPrequelTheNightOfTheDoctor The Night of the Doctor]]"; [[Literature/EighthDoctorAdventures the novels]], [[AudioPlay/BigFinishDoctorWho audio plays]] and [[Magazine/DoctorWhoMagazine comics]] made it clear early on that they're not concerned with outright contradicting each other for the sake of telling their own stories. The 40th anniversary audio drama "Zagreus" has the Eighth Doctor see alternate Universes and mention his adventures in other continuities.
*** Though in "The Night of the Doctor" he does mention his Big Finish companions and Big Finish tries to fit in with New Who.
** There's the Cybersnarl created by the incompetent attempts to tie "[[Recap/DoctorWhoS22E1AttackOfTheCybermen Attack of the Cybermen]]" in with "[[Recap/DoctorWhoS4E2TheTenthPlanet The Tenth Planet]]", "[[Recap/DoctorWhoS5E1TheTombOfTheCybermen The Tomb of the Cybermen]]" '''and''' "[[Recap/DoctorWhoS6E3TheInvasion The Invasion]]".
** These are by no means the only fraught areas of ''Doctor Who'' continuity. In what order did the original series' Dalek stories happen? (In particular, when does "The Daleks" take place and why are the Daleks in that story so different from all others seen later?) How many Doctors have there been (watch "The Brain of Morbius", although the novelisation clears it up a bit)? What was Atlantis like, and how did it sink? And how many ''times'' did it sink (And yes, this question ''is'' more complicated than it first appears)? How do Time Lord family relationships - in particular, the Doctor's - work? What are the Laws of Time and for that matter, are they laws in the scientific or legal sense? And most of that list arises just from the TV series.
** And then, add in the novels and the comics. Normally, as with ''Star Trek'', these are dismissed as non-canon, but is it really non-canon when Sylvester [=McCoy=] and Sophie Aldred (7 and Ace, respectively) reprise their roles for the audio dramas? The BBC has no canon policy at all; the only requirement laid down by the Beeb is "No television story has to depend on the off-screen material to make sense."
** In the immortal words of current producer Creator/StevenMoffat: "It is impossible for a show about a dimension-hopping time traveller to have a canon." - there's a reason why one of the best episode guides for the show is titled "The Discontinuity Guide".
** The UNIT dating controversy is lampshaded by the Doctor in the new series, who mentions not being entirely sure when precisely he worked for them, narrowing it down to roughly some time in the 70's or 80's. In "The Day of the Doctor" has Kate Stewart (the Brig's daughter) mention that UNIT used a few differing dating methods back then, so even ''they'' are a little muddled on the issue as well.
** It was assumed through most of the Moffat era that the aborted "metacrisis" regeneration from the RTD era did not count as a full regeneration towards the thirteen-regeneration limit. In "Time Of The Doctor" it was revealed that it ''did'', which retroactively screwed up a lot of Moffat stories. For example, when the Doctor is poisoned in "Let's Kill Hitler", he says to himself that he'll just regenerate and the TARDIS informs him that the venom blocks regeneration...but he was already out of regenerations anyway, so regeneration would never have been an option and he has no reason to lie when he's the only one listening. Some inconsistencies can be handwaved as lack of character knowledge, but it makes no sense that, say, the Silence (a religious order dedicated solely to studying and killing the Doctor) didn't know about his regeneration but the Daleks (who previously had all knowledge of the Doctor erased) do.
** Also, in "Nightmare in Silver", the Doctor said that he could force a regeneration to get the Cyber Planner out of his head, which is again contradicted by the Eleventh Doctor being at the end of his regeneration limit.
** Doctor Who avoids it more than most decades-long franchises because the show embraces its NarmCharm so much and features TimeTravel. It's got no "why do the Klingons look different" situations because Zygons are still red, rubbery, and suction cup-y, and Daleks are still evil pepper shakers of doom - prop quality has advanced but the look hasn't - and no "why did the year 2000 look super futuristic then but now look like the actual year 2000 did" questions because cracks in time ''ate'' that Dalek invasion you don't remember - the malleability of reality in this show means ''it's part of continuity that continuity is flexible.'' The TARDIS interior goes from [[{{Zeerust}} the 60s and 70s idea of futuristic]] in the 60s and 70s to looking organic because it's a LivingShip in the Russell T Davies seasons to TheAllegedCar, Spaceship Edition in the Amy and Rory years to TheNewTens' idea of futuristic in the Clara years because it's a LivingShip, GeniusLoci, and EldritchLocation that can change anything about its inner dimension on a whim. Some things seem more advanced [[CosmeticallyAdvancedPrequel at an earlier point in their own history]] for simpler reasons -- aesthetics change and in the year 5000 when he'll be made, K9 will look modern again.
* As mentioned above, ''Franchise/StarTrek'' also suffers from this, despite efforts from the writers to avoid this.
** A particularly embarrassing debate is the question of why Klingons look completely different in [[Series/StarTrekTheOriginalSeries the original series]] to the rest. And a Klingon easily passing himself off as human was a plot point in one episode, so it can't be excused as SpecialEffectsFailure. It was {{lampshade|Hanging}}d in one ''[[Series/StarTrekDeepSpaceNine Deep Space Nine]]'' episode, but deliberately wasn't explained (the ''[=DS9=]'' writers [[WordOfGod stated]] they realised any explanation, especially a virus-based one (which they had considered but abandoned) would be underwhelming, forced and ridiculous so decided to acknowledge it in a humorous way but not insult the fanbase with a horrible technobabble solution). ''[[Series/StarTrekEnterprise Enterprise]]'' made it worse, with their ridged Klingons (so they had them, then lost them, then got them back?) and decided to create an explanation in the fourth season, which is when it ''truly'' remembers "we're a prequel series" and starts to tell the story of how the TOS-era Franchise/TrekVerse came to be. [[spoiler: The TOS Klingons are the descendants of several Klingon colonies that got infected by a virus that caused a genetic mutation that made them look more human. Said virus was created by a Klingon scientist hoping to enhance Klingon soldiers using DNA from genetically engineered humans, after said genetically engineered humans 1) kicked their asses, 2) stole one of their ships, and 3) flew circles around the Earth Starfleet's flagship.]] Apparently, reconstructive surgery in the ''Enterprise'' episode suggests that individual gene therapy became possible between ENT and ''Deep Space Nine'', thus explaining Kang, Kor, and Koloth's sudden appearances of ridges in the latter, and also the appearance of ridged Klingons in ''Film/StarTrekIntoDarkness''. The video game ''VideoGame/StarTrekOnline'' tries to fix this by explaining that B'Vat, a war-hungry Klingon from the 25th Century kidnapped Miral Paris, daughter of [[Series/StarTrekVoyager B'Elanna and Tom Paris]] and MessianicArchetype the Kuvah'magh, brought her to the 23rd Century and used her DNA to fix them.
** The change in their MO from "The Russians [-IN SPACE!-]" to {{Proud Warrior Race Guy}}s is hinted at in one recently-affected Klingon mentioning having felt fear for the first time since childhood. Apparently they got more underhanded because their personalities were also altered to be more human.
** The Romulans have actually been snarled for longer than the Klingons. Originally, Romulans were indistinguishable from Vulcans, until TNG re-introduced them and added v-shaped brow ridges, then flip-flopped by having Spock able to pass as a Romulan despite having no ridges. Then there are Romulan spies masquerading as Vulcans and vice versa, with brow ridges apparently having no bearing on easy identification. ''Enterprise didn't'' explain how they went from ridged in TFE to not in TOS to ridged again (sorta) in TNG. Then the new movie makes it worse still: Nero and company are not ridged! And no, AlternateUniverse doesn't explain things, because it's post-TNG Romulans from the prime universe who changed history. They are ''very much'' the same Romulans that existed alongside Picard et al.
** In the prequel comic to ''Film/StarTrek'' (2009), ''Star Trek: Countdown'', it's stated that Nero's crew ritualistically disfigured themselves as a demonstration of mourning for their lost homeworld. You can see in the very first scene with Nero that he has both pointed ears intact, while later in the movie one ear has had the point cut off. The same scene also has much more prominent brow ridges on Nero's face than later in the movie, so it's likely that distorting their ridges was another part of the mourning, along with the tattoos.
*** The loss of the ear came in a DeletedScene, where Kirk Sr.'s ramming of the Narada disabled the craft and allowed Klingons to capture the Romulan crew. The disfigured ear was the result of some, uhh, EnhancedInterrogationTechniques on the part of the Klingon captors. (This scene also explains why Nero laid low for 20+ years.)
** Furthermore, the tattoos sported by Nero's crew are given an explanation: Romulan tradition states that when a family member passes away, they apply dyes to their skins, and mourn. When the patterns fade, they move on with their lives. Nero's crew tattooed the symbols onto their bodies, so that they would never move on from the loss of Romulus.
** And then there's the Eugenics Wars. In the 1967 episode "Space Seed", it's established that the Earth was devastated in [[TwentyMinutesIntoTheFuture the 1990s]] by a great war fought against (or possibly between) [[BewareTheSuperman genetically-engineered supermen]]. Trouble is, ''Star Trek'' was still going strong by the time the actual '90s rolled around. And some episodes made in that time and afterwards seem to suggest that the '90s happened like they did in RealLife. But the Eugenics Wars are still {{canon}} and an important part of ''Star Trek''[='s=] BackStory as they are the origin of iconic villain [[Film/StarTrekIITheWrathOfKhan Khan]], as well as being the cause of a centuries-long taboo on genetic augmentation of humans that is a major plot point on ''Deep Space 9''. This has never really been officially resolved, although author Greg Cox wrote a series of ''Star Trek'' novels covering the Eugenics Wars, depicting them as happening [[SecretWar in secret]] and trying to match it all up with real history.
*** This is thrown out the window by a comic series that has the Reboot!Khan explaining his origins. In his version of history, the Augments did indeed stage a takeover in the 90s, which took all of two weeks. They then started fighting with one another, allowing humans to band together and throw them off. Khan's people are the only ones that made it out thanks to him devoting most of his time to research (he had the SS ''Botany Bay'' built to explore the Solar System). Marcus then found the ship, had Khan thawed out, reshuffled his face, and gave him LaserGuidedAmnesia to make him think he really was a Section 31 agent named John Harrison. "Harrison" proceeds to upgrade the ''Vengeance'' and re-invents Scotty's long-range transporter, before heading over to blow up Praxis.
** Another such snarl was created by a throwaway line from The Next Generation where Data points out that Andorian marriages have four individuals in them. One series of tie-in books took this to mean that Andorians have four sexes, with other books taking it to mean that the Andorians practiced complex marriage with two males and two females. Canon had been ambiguous on the issue for years, but eventually went with the complex marriage interpretation by the time of Enterprise.
** The first appearance of the Borg in "Q Who" established them as something completely alien to the Federation, and it's even stated that they wouldn't have discovered humanity for a while longer if Q hadn't introduced Picard to them. Fast forward to the introduction of Seven of Nine on ''Voyager'', whose backstory is that she was captured by the Borg as a child when her parents were on a trip looking for them, long before "Q Who." If you really want, you can say the Borg's time travel in the ''First Contact'' film created some timey-wimeyness that changed all this, but it's probably more trouble than it's worth.
*** Also on ''Voyager'', a couple of formerly-human Borg are said to have been assimilated at Wolf 359. How this could have happened is unclear, since there was one Borg cube there that was completely destroyed in Earth orbit, and if anyone from the fleet at Wolf 359 had been assimilated they would presumably have been killed then.
*** Then there's the ''Enterprise'' episode that has two drones from the Queen's Sphere survive the crash, assimilate a bunch of scientists, hijack a transport ship and start heading towards the Delta Quadrant. After the ''Enterprise'' destroys it, Phlox reveals that they managed to send a message. Archer figures the subspace message would take about 200 years to reach the Delta Quadrant, putting it in TNG timeframe.
** Ron Moore discusses the issue in the commentary for ''First Contact'', talking about what a pain it was to retcon the Borg Queen into "The Best of Both Worlds," and suggesting that whoever takes over ''Trek'' next should probably just jettison the decades of continuity and start over.
* ''Series/TheBigBangTheory'': The season 1 episode "The Hamburger Prostulate" mentions that Sheldon is allergic to cats, but later episodes mention that he had a cat when he was a kid. "The Plimpton Stimulation" even states that getting a pet was against the "Roommate Agreement" unless it was necessary, like a Seeing Eye Dog.
** Possibly lampshaded in "The Zazzy Substitution" (Season 4, Ep 3) where Sheldon reacts to his breakup with Amy by getting a cat ... then several more. 25 in all.
* Don't try to figure out ''Series/{{MASH}}''[='s=] [[FrozenInTime timeline]][[note]]not at all helped by the fact that the series was on for more than ten years while the actual Korean War finished in just over three[[/note]]. Many have tried and it just gave them a headache:
** To get into the show's worst offenses, when Colonel Potter takes over the camp, it's explicitly stated to be September 19, 1952, but a later episode opened on New Year's Eve, 1950 with Potter and Winchester there. And UsefulNotes/TheKoreanWar started in late June of 1950, so apparently the show's first ''five seasons'' with Colonel Blake and Frank took place over the course of ''barely more than five months''. And early episodes with Blake and Frank tended to give the year as 1951 or 1952. And the September 19, 1952 date doesn't work very well even on its own since it requires that ''eight seasons'' take place over the course of ''ten months''.
** The Boxing Day episode begins on Christmas Day, with some British officers visiting the unit talking about wanting to get back to their own unit for Boxing Day, which doesn't correspond well with events of any of the other Christmas episodes.
** In a Season 3 episode, Hawkeye talks about the death of Doctor Charles Drew and says it was "last April." Drew Died in April of 1950. That would put this episode some time in 1951.
** A few episodes later in Season 3, Hawkeye says he's been in Korea for two years. If he got there when the war broke out in June of 1950, which doesn't seem likely since he was drafted, that would make it some time in 1952 at the earliest.
** In the episode where BJ arrives, Hawkeye states that he had Trapper as his roommate for over a year, and in another he states that Trapper was already at the 4077th when he arrived. That doesn't work with the above statement he's been in Korea for two years when Trapper was still there.
*** Shortly thereafter, Hawkeye mentions that Nixon is Vice-President. Nixon was elected Vice-President in November 1952 along with President Eisenhower, but wouldn't have been inaugurated until January 1953. Even if you make the argument that Nixon is still Vice President-Elect, this puts this season 4 episode in late 1952. Seeing how many later episodes reference Truman as president and one episode lasting a year, there's no way to reconcile this episode's status as early in BJ's tenure since it's devoted to his writing a letter to his wife telling her about his relatively new situation.
** It gets worse if you try to reconcile the series with the actual course of the Korean War. Every episode seems to take place at a point in the war when Korea is divided about evenly between communist and allied forces. Seoul is consistently under allied control and the 4077th is regularly said to be located near Uijeongbu. This makes it unlikely that many episodes take during the first year of the war, when the front lines were moving rapidly. Instead, the whole series appears to take place during the final two years of the war, in which there was a WWI-style stalemate in the center in the Korea.
* In ''Series/TheSuiteLifeOfZackAndCody'', Maddie asks London's help to pass gym when she realizes that, despite her [[RichBitch pampered lifestyle]], the rich girl is in great shape. In the sequel show, Suite Life On Deck, London suddenly needs Zack's help to pass gym.
* ''Series/ICarly'', ''Series/{{Zoey 101}}'', and ''Series/{{Victorious}}'' share [[Series/NickVerse a universe]] resulting in a CelebrityParadox. ''Series/DrakeAndJosh'' is a piece of RecursiveCanon in that universe, and has Creator/DrakeBell the actor (not Drake Parker the character), show up in ''Zoey 101''. Then in "iStart A Fan War", an episode of ''Series/ICarly'', they include a cameo by a pair of ''Series/DrakeAndJosh'' characters. One episode even has Carly and Spencer watching an episode of ''Drake & Josh'', and the ''Series/{{Victorious}}'' episode "Who Did It To Trina" explicitly states that ''Drake & Josh'' is a TV show. Even though the episode before it had Helen, one of the main characters ''from'' ''Drake & Josh'' appear and reference characters from ''Drake & Josh''.
* In ''Series/{{The Office|US}}'', toward the end of the fifth season, in a rare instance where two people are talking to the camera, Pam and Jim are talking about how Andy and Angela had been engaged for a couple of years, but then said that the timeline was complicated.
* ''Series/KamenRiderOOO''[==]'s [[EarlyBirdCameo appearance]] in ''Series/KamenRiderDouble''[==]'s movie and their crossover movie ''Movie War Core'' has... issues with ''OOO''[='=]s TV series continuity. Whilst this would not be a problem for ''Franchise/KamenRider'' traditionally (what with each Heisei Rider series until ''Series/KamenRiderDecade'' being self-contained) the fact that ''Double''[='=]s canon across all medias is very tight creates ''OOO''[='=]s problems. Examples include Gotou becoming Birth (his ''not'' getting to be Birth is a major part of his character arc) and OOO's medal count (he switches between forms he never had all the medals for at the same time at any point in the series.)
** And Giru ''existing.'' In the series, Giru is [[spoiler: never active. A complete set of ten Core Medals for a dinosaur Greeed exists, and five wind up in Eiji and five wind up in Maki]]. Also, there were {{Out Of Character Moment}}s with the OOO crew, as all the details of the series hadn't been finalized when the movie was produced. This results in a movie that is clearly a direct continuation of ''Double'' but just as clearly ''can't'' be in continuity for ''OOO''.
*** Making it more confusing, every crossover from that point on has references to the previous one. In ''Movie Wars Core'', Eiji (OOO) helps save one of Shotaro (Double)'s friends, prompting Shotaro to say "That's another one I owe you", referring to Eiji's BigDamnHeroes moment from the ''Double'' movie. In ''Movie Wars Megamax'', Shotaro mentions repaying this debt, as well as quoting what Eiji said when they first met[[note]]"Riders should help each other out."[[/note]]; on top of that, Eiji recognizes Gentaro (Series/KamenRiderFourze) thanks to '''his''' BigDamnHeroes moment in the stand-alone ''OOO'' movie.
*** One possible explanation for why the continuity of ''OOO''[='=]'s segment doesn't fit with that of the show is that said segment takes place over time - with the exception of Giru and the {{Out Of Character Moment}}s for the cast, the rest can be accounted for this way. Although it's also worth noting that in the movie, the [[CoolBike Toride Vendor]] is shown being able to fly, an ability it does not have in the show[[note]]given that the Toride Vendor uses the Tora Candroid, it's entirely possible that if the Taka Candroid was used, it could create a bike with flight mode, but that's not what happens - not in the movie, nor in the TV series[[/note]].
** On the topic of ''Kamen Rider'', there's the 3 [[MultipleEndings alternate ending films]] for ''Series/KamenRiderRyuki'', ''Series/KamenRiderFaiz'', and ''Series/KamenRiderBlade''. While there's evidence in all 3 as to when they are supposed to take place, all 3 of them have elements that contradict what's happened in the series proper - i.e., ''Episode Final''[[note]]''would'' take place after episode 46[[/note]] has Shinji and Yui meet prior to the series, which is never stated; ''Paradise Lost''[[note]]''would'' take place after episode 25[[/note]] has the Delta gear destroyed, whereas in the series proper, it's still in tact at the time the movie takes place[[note]]although the differences are explained in [[AllThereInTheManual an SIC Hero Saga story]], indicating that the Saga and the movie are the result of ForWantOfANail[[/note]]; and ''Missing Ace''[[note]]''would'' take place after episode 47 of ''Blade''[[/note]] a), incorrectly states that humanity was the winner of the Battle Royale that occured prior to the series (when it was the Human Undead), and b), [[spoiler: by having the [[TheAntiChrist Joker Undead]] be the last Undead to be sealed, technically means that the Joker Undead won the Battle Royale depicted in the series, when it's established that, should that happen, TheEndOfTheWorldAsWeKnowIt will happen (yet it's stated that the movie is set 4 years after the TV series)]].
* There have been three seasons of ''Franchise/PowerRangers'' that have shown variations on the future: ''Series/PowerRangersSPD'' (2025), ''Series/PowerRangersTimeForce'' (3000), and ''Series/PowerRangersRPM'' (undefined; somewhere between NextSundayAD and TwentyMinutesIntoTheFuture). Trying to fit them together can be problematic, especially since the various showrunners are unclear on whether or not ''RPM'' is an AlternateContinuity. (Of course, it's not too hard to weld together the three seasons, since ''Time Force'' shows wastelands that could have been created in ''RPM''. The biggest bone of contention about ''SPD'' revolves around the amount of aliens living on Earth which had disappeared before the chronologically later seasons. It's not a huge stretch to assume that by the time of ''RPM'' and ''Time Force,'' the aliens have become HumanAliens by either adapting to Earth's atmosphere or integrating with humans.)
** The ''Series/PowerRangersSamurai'' team-up "Clash of the Red Rangers" officially shoved ''RPM'' into an AlternateContinuity by saying ''RPM'' took place in another dimension.
** In "Alpha's Magical Christmas", a direct-to-video musical released during the second season of ''Series/MightyMorphinPowerRangers'' has many continuity errors such as the team already being acquainted with Rocky, Adam and Aisha, even though Tommy is still wearing his Green Ranger costume and not the White Ranger one, while Jason, Zack and Trini are "[[PutOnABus at the Peace Conference]]", even though they're still Rangers.
** Here's another one for you: When did Power Rangers first start showing up on earth? In ''[[Series/PowerRangersDinoThunder Dino Thunder]]'', Tommy claims that the Series/MightyMorphinPowerRangers were the first, but then you have seasons like ''[[Series/PowerRangersWildForce Wild Force]]'' and ''[[Series/PowerRangersMysticForce Mystic Force]]'' where the organizations the Rangers belong to have existed for decades or even millennia. And even if you argue that those organizations may not have had actual Rangers until their respective seasons began, ''Series/PowerRangersSamurai'' outright states that the Samurai Ranger powers have been in use and passed down throughout family lines for ''centuries''. We see flashbacks to the earliest Samurai Rangers in ''ancient Japan'' with the ''exact'' same {{Magitek}} as they present ones use; the only difference is previous teams seem to use the ''Shinkenger'' version of the morphers.
** ''Dino Thunder'' does its best to try and tie together all the previous series by being the first since ''[[Series/PowerRangersLostGalaxy Lost Galaxy]]'' to acknowledge that they all exist in the same universe, but creates more inconsistencies, in addition to the above mentioned, Tommy himself is one. First off he is shown working for Doctor Anton Mercer a few years prior. However this contrasts with his previous appearance in the ''Wild Force'' episode "Forever Red" where he owns the local hangout and is implied to have a bit of money which seems quite different to assisting a dinosaur professor.
** ''Series/PowerRangersDinoCharge'' just inflated the Snarl UpToEleven with their second finale, the result of whose TimeTravel Plot resulted in only one change: The dinosaurs never went extinct and live with Humans in the modern age. As there are implications that the resulting battle possibly wiped out the Prime Timeline, this [[TimeyWimeyBall potentially screws with or outright Retcons]] much of the canon established for almost all of MMPR up to ''In Space''[[note]]As Zordon powered the Power Coins with energy from the extinct dinosaurs and Saber-toothed Tiger; while the other season suits were [[MidSeasonUpgrade re-models]] of the initial ones.[[/note]], Series/PowerRangersDinoThunder,[[note]] [[SharedUniverse Which operates on being connected to every other previous season]].[[/note]] and Series/PowerRangersSPD.[[note]]Which is the second-furthest series in the timeline that acknowledges the past frequently.[[/note]] Until WordOfGod addresses it though, [[RuleofCautiousEditingJudgement speculating is useless.]][[note]]in fact, the only previous series that one can say with complete certainty ''wasn't'' retconned by the ending of ''Dino Charge'' is the aforementioned ''RPM'', thanks to it explicitly being established to be in an alternate dimension, since crossovers between seasons and ''Series/PowerRangersMegaforce'' establishing that all ''RPM'' is the only pre-''Megaforce'' season not to be in the main dimension[[/note]].
* ''Series/RebootTheGuardianCode'': Thanks to a TroubledProduction and a producer who admitted internally that he'd never watched more than a couple episodes of the first season of [[WesternAnimation/{{Reboot}} the cartoon]], attempts to place the two shows in continuity with each other ran smackdab into this issue by the time the first-season finale rolled around.
** The four main characters learn that the original Mainframe server has seemingly been rebooted, which has set all of the characters inside back to their original factory defaults. Not only does this result in nearly the entire population of the original Mainframe (including Fong, Hack & Slash, Mouse, Mike the TV and all of the other Sprites) being absent for no reason, but Bob is also present on the server, despite the original pilot episode of the cartoon establishing that he is a Guardian who travelled to Mainframe and wasn't present when it was initially formed.
** Additionally, the characters are greatly changed from their first appearances in the series. Bob is missing most of the personality he had in the original pilot episode when he is re-introduced, and his opening lines are the speech given at the beginning of each episode of the cartoon. Hexadecimal inexplicably has the ability to have facial expressions (something she was expressly given then had taken away in the ''My Two Bobs'' season). Conversely, Dot Matrix (an ActionGirl and savvy businesswoman in the cartoon) ''hides behind her kid brother'' when Megabyte threatens the group.
** The User (a BasementDweller fanboy who is obsessed with Mainframe) is revealed to have collected merchandise suggesting that events from later on in Mainframe's timeline canonically happened (including the events of Seasons 3 and 4), but have somehow become a ShowWithinAShow that was marketed to great success.
** It is claimed by the User that he's finally going to win a Game for the first time in 20 years. This disregards multiple instances where the User won games in the cartoon, including one that occurs ''in the first ten minutes of the pilot'' (Hack & Slash bar Bob from entering a game, causing all the Sprites inside to perish when the User wins), along with a very notable case at the end of Season 3 as well as several instances that occur off-screen throughout Season 4.
** The sequence with the User accessing Mainframe again suggests that the system is actually some type of online server that has reactivated -- except it throws continuity under the bus within the same episode by showing that Mainframe is ''already'' running on a server locating within Room 01 in the school. Additionally, this is a marked change from the original cartoon, where the entire show is implied to have been running solely on the User's computer -- the finale of the original run was caused by Enzo, Bob and the other Sprites allowing so much damage to happen to the computer (due to botched Games and the null errors it generated) that the User was forced to reboot the operating system to get it back to working order.
* ''Franchise/SuperSentai'' is no stranger to this. At first its different series didn't try to be in continuity, but teamup episodes do. As they get bigger and bigger, there's now one continuity that seems to contain every franchise ever owned by Creator/ToeiCompany and every franchise Creator/ShotaroIshinomori ever had a hand in. Even so, they don't even try to make them fit now that such crossovers are a thing! For example:
** ''Series/ZyudenSentaiKyoryuger'' comes ''after Series/KaizokuSentaiGokaiger'' met members of every team ever at least once. It ''still'' comes up with a new take on how PhlebotinumKilledTheDinosaurs that's totally incompatible with all others[[note]]although it's worth noting that the takes in ''Zyuranger'' and ''Abaranger'' both contradicted each other as well, even before the one in ''Kyoryuger'' was created[[/note]].
** When ''Series/KamenRiderDecade'' meets ''Series/SamuraiSentaiShinkenger,'' it's as the next AlternateUniverse in line as Decade continues his journey through the worlds. It's said more than once that this world has never had Kamen Riders. When ''Series/KamenRiderGaim'' meets ''Series/ResshaSentaiToQger,'' the city ''Gaim'' takes place in is just the next stop on the TOQ trains' path. When ''Series/KamenRiderDrive'' meets ''Series/ShurikenSentaiNinninger,'' they're separate dimensions again, and not only that, the Ninningers stuck in the world of Drive can only remain for a short time before ceasing to exist - a problem that never appeared in any other crossover.
** Any movie with "War" in the name will have the different Riders and Sentai able to just happen across each other as if they were just in the neighborhood. Even if due to the existence of Decade, Den-O, and Timeranger, time travel and dimension travel are ''acknowledged,'' it's never used to say that these are characters with their own self-contained timelines who normally cannot meet. Worldwide invasions will the same {{Mooks}} landing outside the school in Fourze and the base in Go-Busters at the same time before anyone knew what was going on to ''try'' crossing dimensions or any such thing.
** Speaking of time travel, some alternate timelines do ''not'' get fixed, even as the individual series involved air just as normal next week. Most notably, if the "Let's Go Kamen Riders" movie counts, the world was ruled by a coalition of villains from TheSeventies to the present day, when all the Kamen Riders who should never have come to be in that timeline were pulled from throughout TheMultiverse to clean up. Naturally, OOO continues to tell its story without any sign of having transformed into a former VillainWorld that was only just brought BackFromTheBrink ''yesterday.'' (You really have to wonder what this means for Mitsuru and Naoki, two kids from the original Kamen Rider who were very important to the film. If the movie doesn't happen, they technically shouldn't have been there... it's best not to think about these things.)
* Frasier Crane famously told his friends at ''Series/{{Cheers}}'' that his father was a research scientist and had died years before. This was {{handwave}}d in his SpinOff series ''Series/{{Frasier}}'' as having been something he said because he was angry at his dad that day, but it was in fact not something that was said once; his characterizations of his father and his identifying himself as an orphan took place consistently over quite some time during his years in Boston.
** Frasier's mother visits him during his engagement to Diane, and is almost psychotic at the thought of her son marrying a mere barmaid. This doesn't fit in well with Frasier's claims to be an orphan, or her posthumous characterization in ''Frasier,'' and raises the question of when, exactly, she died.
* ''Series/{{Degrassi}}'' fixed a year issue caused by Seasons 6-9 each being half a school year long. Causing time in series to lag behind the real world. So start of Season 10 it is suddenly current year, 2008 to 2010 over the summer break... But given Emma's birthdate is a fixed point, and her first day at Degrassi is also fixed by the Class reunion of the DJH characters, this makes a lot of interactions between Seasons 7-9 problematic. Specifically between characters like Sav and Holly J with characters like Paige and Spinner.
* ''Series/PrettyLittleLiars'' is starting to run into this especially where Jenna and Toby are concerned. This is probably the result of initially following their book characterizations then pulling a WhamEpisode regarding them and developing them into their own characters but''keeping their new characters for flashbacks where they should be their old selves.'' Jenna isn't too bad since she's made out to be a BitchInSheepsClothing in the early books but Toby goes from a creepy loner EmoTeen pre-character development to having always been an IronWoobie with no hints of creepiness.
* ''Series/HerculesTheLegendaryJourneys'' and its spinoffs ''Series/XenaWarriorPrincess'' and ''Series/YoungHercules'' were notorious for this. Some specific examples:
** "Hercules and the Amazon Women" established Hercules, Iolaus, and their peers as having been conditioned since birth to believe women are inferior and should StayInTheKitchen. After meeting the Amazons for the first time, Hercules slowly realizes that this line of thinking is wrong and becomes respectful to women for the rest of the series. However, Hercules and his friends met the Amazons and several other {{Action Girl}}s as teenagers in ''Young Hercules'', and had plenty of respect for women at this time.
** The god Strife gets killed by a god-slaying weapon in "Armageddon Now: Part 1", and Zeus gets killed in "God Fearing Child", yet Strife appears in "Yes Virginia, There Is A Hercules" (which is set in the modern day), while Zeus is mentioned as being active. Some fans have {{Handwave}}d this by suggesting the two may have been resurrected somewhere down the line.
** In ''Young Hercules'', Jason was a teenager just like Hercules and Iolaus. In the main series, Jason is an old man who eventually dates and marries Hercules' mother Alcmeme and had been an active soldier when Hercules had been conceived.
** "Ten Little Warlords" claims Ares' sword is the source of his powers. When it is lost, he will lose his powers and whoever claims it will become the new god of war. In the meantime, everyone becomes overly aggressive because there is no god of war to control anger and hate. In other episodes, Ares' powers are internal just like every other god. Also, when he is depowered at other times, people's personalities stay the same.
** "Hercules in the Underworld" has Hercules venture into the Underworld and meeting Hades for the first time. Hercules did it as a teenager in an episode of ''Young Hercules''.
** Zeus' twin sons Castor and Pollux appear in ''Young Hercules'' and Castor eventually gets murdered. Castor and Pollux later appear in the ''Xena'' episode "Little Problems"... and are portrayed as conjoined twins.
* ''Series/{{Friends}}'':
** As a long-running show there's bound to be one or two things that don't add up, but a pretty bad one occurs in Season 1 that there's little excuse for because it comes about in the space of two episodes right at the start of the show. There's barely any continuity to screw up. One episode centres on Ross moping because it's the anniversary of his first having sex with Carol (and also losing his virginity). Monica is the one who first remembers, which is {{Squick}}y but Ross says there were few people he didn't tell. In the very next episode, Monica says the line "Wow, my brother didn't even tell me when he lost his virginity."
** Chandler and Rachel are shown interacting in Thanksgiving flashbacks to their teen years, and in a flashback to a few months before the series began, and yet in the pilot they're introduced as total strangers. Ross gets a "You remember..." before his name, so Chandler ought to as well.
** In one of the early episodes, Phoebe is talking to a professional guitar player, Stephanie, and knows the real names of the chords. Several seasons later, when she was teaching Joey how to play a guitar, she appeared not to know the real names, and instead used her own made-up names (like Bear Claw).
* ''Series/HowIMetYourMother'', a show normally [[ContinuityPorn outstanding in its continuity]], has a couple of small errors. For example, at Lily and Marshall's wedding, Scooter states that his real name is Bill. But in season 8, it's revealed that his original name is Jeffrey.
** In the first season, Marshall comments that he's never been in a fight before. However, later seasons reveal that years of brutal fights with his brothers have made him an excellent fighter, and he is able to knock out a large man with one punch.
** The season 1 HalloweenEpisode has Robin give a big speech about how she could never play team sports - and would only play tennis - establishing that she has trouble mixing with others. A handful of episodes later has her state that she missed her prom for field hockey nationals. Subsequent episodes referenced her hockey background.
** In the season 4 episode "Little Minnesota," Robin and Marshall bond over their similar backgrounds (she misses Canada; he misses Minnesota). They spend the whole episode hanging out with each other and going to Canada/Minnesota-themed bars. Despite this, the season 6 episode "The Mermaid Theory" revolves around the fact that Robin and Marshall have never spent any time with just the two of them.
* ''Series/{{Misfits}}'' took the odd step of dating its final episode as taking place exactly a year after its first. This removed the implausibility of people keeping their crazy powers a secret for years at a time, but made it pretty much impossible for the show's 37 episodes to fit into that time period. Most episodes take place over a few days or weeks and most of the season premiers imply that months have passed while the show has been off air.
* ''{{Series/Charmed}}'' was notorious for its numerous continuity errors, especially in the sixth season, where Chris Perry -- a KidFromTheFuture -- appeared to stop the Titans from conquering the world. When he gets his origin episode in season 6, there is no mention about the Titans [[spoiler: and his brother Wyatt is the BigBad in the future]]. He also orbs into the attic in his debut episode but this shows him going back in time via a portal in the attic wall. Additionally his hair was short when he arrived on the show but the actor grew it long for season 6 -- and it's the same in his origin episode.
** Chris says that Paige died in his debut episode, claiming to have prevented her death. In a season 6 episode, he tells her he goes to her for money in the future.
** In a season 4 episode Phoebe says that her grandmother was married six times. Later episodes RetCon this to Penny only being married four times and engaged six altogether.
** Patty and Victor's relationship in the past becomes more convoluted as the show goes on. It's implied in season 1 that Victor left Patty when he found out she was a witch. Numerous time travel and flashback episodes complicate matters even further as Victor and Patty appear to have broken up and reconciled quite a few times. The series finale in particular flashes back to when Phoebe was conceived and Patty and Victor seem to be fine. This contradicts season 1's "That 70s Episode" where Patty and Victor have been separated for a while and Patty doesn't know she's pregnant with Phoebe yet. The story is also initially that Victor left the girls to be raised by Penny. Season 3's "We All Scream for Ice Cream" says that he stuck around for a while after Patty died but then left again.
** Good luck trying to make any sense out of how being a Whitelighter is supposed to work. First it is treated as a voluntary position you can refuse when offered and later resign if you wish, but later in the series people are forced into being Whitelighters. The psychic connection Whitelighters have to the people they are assigned to protect varies from knowing when they are specifically called upon to literally feeling their pain constantly. A Whitelighter fathering a child with a witch is first treated as unthinkable when Piper and Leo get close. Then it is revealed that the mother of the three Charmed Ones had another child (Paige) with her Whitelighter. Admittedly that was kept a secret, but in the last season yet another half-Whitelighter witch shows up and nobody thinks it is particularly that unusual. Piper's and Leo's first child Wyatt is insanely powerful due to being half witch (or maybe specifically half Charmed) and half Whitelighter, but it is never addressed why the same does not apply to their second child or Paige.
* ''Series/AmericaUnearthed'': It happens a lot that the theory of a particular episode, if proven true, would invalidate one or more previous theories. The easiest to explain case would be in the first season when the Holy Grail would go back and forth between being a cup/chalice to the holy bloodline of Christ (like the Davinci Code).
* In the third season of ''{{Series/Arrow}}'', Oliver Queen is outed as The Arrow by Ra's Al Ghul and is captured by the Police. They solve this by having his partner Roy wear the Arrow costume and deliver himself to the authorities, claming that he's the real Arrow. The problem is that in season 1 Roy is saved from a murderer by The Arrow ''on live TV'', which would disprove his false confession, yet apparently no one remembers that by the third season, so his confession is accepted.
* ''Series/RoboCopTheSeries'' sees this with regards to when in its timeline Alex Murphy was turned into the titular cyborg. The pilot states that [=RoboCop=] and Pudface Morgan had the encounter that disfigured Morgan five years ago. However, in the episode "Zone Five", it was stated that Murphy was killed (the very thing that allowed OCP to use him to make [=RoboCop=]) three years ago.

[[folder:Mythology and Religion]]
* All over the place in Myth/ClassicalMythology, the only long-running franchise to have three millennia of retcons:
** Case in point, Venus/Aphrodite's origin story. Was she the daughter of Jupiter/Zeus? Or was she born from the sea foam from when Ouranos/Uranus's testicle fell into the sea, long before Zeus was conceived?
*** Or take Eros. Was he the son of Aphrodite and Ares, as he is usually depicted in Western art from the Renaissance onward? Or was he one of the eldest deities of all, born out of the original Chaos alongside his siblings Gaia (mother of Ouranos) and Tartaros, as described by Hesiodus in his ''Theogony''?
** Hephaestus's origin is a crazy example. Okay, so he was born when Hera gets annoyed that Zeus apparently gave birth to Athena on his own. She tries it, and she gets a very ugly baby. So she [[ValuesDissonance tosses it off Olympus.]] That baby is raised to become the greatest smith ever. He is then welcomed into the pantheon. At some time afterwards, he hits Zeus over the head with an ax while Zeus has a headache, and Zeus gives birth... to Athena. It's like that old "born in a log cabin he helped build" thing.[[note]]The most common explanation is one or both of: Hephaestus is a legitimate son of Zeus and Hera (which works well for establishing that those two make a very bad couple, seeing as how their other son is Ares) or it was Prometheus who split Zeus' head open to let Athena out (which is consistent with the fact that Metis, a titaness, was the mother of Athena; meaning that Athena was probably born not long after the Titanomachy, when Prometheus was still on Zeus' side).[[/note]] Causality is just for mortals!
** When Perseus was returning from his trip to decapitate Medusa, he met the Titan Atlas and asked to share his hospitality. Atlas was a jerk and refused, so Perseus [[TakenForGranite turned him into a mountain]] with Medusa's head. Perseus' distant descendant, Heracles, later stopped by the same region, where he got the help of a completely healthy and not-at-all-stone Atlas in stealing some Golden Apples. (Keep in mind, Medusa's effect on people is incurable.)
** When Theseus first arrived in Athens at the beginning of his adventures, Medea tried to poison him so that the child she bore from Aegeus will inherit the throne. Years later, Theseus would participate in the Argonaut expedition, which brought Medea to Greece. She got married to Jason, was abandoned by him, then went to Athens and married Aegeus.
** Dionysus was born as a result of his own actions. To elaborate, he was the son of Zeus and Semele, who was descended from Harmonia, a daughter of Ares and Aphrodite who was born after the latter was already married to Hephaestus. However, Aphrodite and Hephaestus only got married because Dionysus got Hephaestus drunk and brought him back to Olympus this way. The reward for bringing Hephaestus back to Olympus was marrying Aphrodite but Dionysus, probably afraid of the already timeline-ripping continuity snarl, refused the reward and said Hephaestus got to Olympus on his own - and he should be the one marrying Aphrodite. Then Aphrodite proceeds to cheat on Hephaestus with Ares and give birth to Harmonia, the ancestor of Dionysus...
* Myth/JapaneseMythology: Was Amaterasu conceived by Izanagi and Izanami while the latter was still alive? Or was Amaterasu the byproduct of Izanagi washing himself of the filth from Yomi? The Kojiki and Nihon-Shoki both say different things. And say nothing of the myth where she sends her grandson to rule over the world...
* What were the circumstances surrounding the death of [[Literature/TheBible Goliath?]] The story as generally remembered is that David was a shepherd boy bringing food to his brothers in Saul's army when he heard of Goliath's challenge to single combat, introduced himself to Saul, and volunteered to fight... except that he was already serving Saul at this point as a musician and armour bearer; Saul should have known who he was and he should have been with his king in the first place. While all this just comes from the first book of Samuel, the second book of Samuel mentions how Goliath was killed by someone called Elhanan, though some bible translations say Elhanan killed Goliath's brother.
** Also from the Bible, the books of Luke and Matthew both give geneologies of Jesus which are completely different for every generation after David. There have been multiple theological attempts to explain this; that one is through Joseph and one through Mary (and that her father is coincidentally also named Joseph) is popular, as is the idea that one is the "legal" genealogy and on the biological one (thanks to complicated inheritance laws), but it's never addressed in the text itself.

[[folder:Pro Wrestling]]
* One of the duties governing bodies like the Wrestling/NationalWrestlingAlliance have is to prevent or remove these, at least when they are in danger of becoming painfully noticeable to large amounts of people. Unfortunately the NWA itself started in an age before VHS or cable and neglected to keep track as those things became steadily less expensive until it was too late. Suddenly the large majority of fans who could only watch television of their own territory could see everything at once. For example, there were a dozen different territories with an equally amount of incompatible NWA World TagTeam Champions. This wasn't sorted out until 1992, with everything between then and 1950 being officially listed as "vacant".
* The Wrestling/{{WWE}}'s "Wrestling/{{Kane}}" character, whose official life story has him having been a hopelessly-insane burn victim in an asylum at the same time he was supposed to have been hanging out in college and going to parties with his sweetheart Katie. Further complicated by the storyline of his "[[Wrestling/TheUndertaker brother]]", who had a whole angle where he [[BreakingTheFourthWall Broke the Fourth Wall]] and "went out of character". The whole thing got so complicated that they had to have somebody write a book (titled ''Journey Into Darkness'' if one should want to look it up) in an attempt to explain it.
** Wrestling/TheUndertaker himself tends to be mildly rebooted when he gets a gimmick change. Different personas don't often directly reference older ones, but this is a double-edged sword; most glaring is when the American Badass started out with the Undertaker doing a worked shoot to sell the idea that he wasn't supernatural ''in'' character as well as out, so he could come back as a leather-clad biker, only for Kane to ''kill him'' so he could be ''resurrected as undead.''
** Occasionally a reference is made to their childhood home burning down, but which brother is responsible depends on who's Heel and who's Face at the time. If they're both Face, it was [[strike:an accident]] Wrestling/PaulBearer's fault. With Bearer dead, WWE being PG, and both men at the tail end of their careers, it's probably never coming up again.
* A good one was in Wrestling/{{WCW}}, where a masked wrestler would run out and attack people during their matches. He was eventually revealed to be Wrestling/RickSteiner. The problem was that the week before said masked wrestler attacked...Rick Steiner.
* Wrestling/{{WCW}}'s Black Scorpion was allegedly someone out of Wrestling/{{Sting}}'s past. It was going to be the Wrestling/UltimateWarrior, but there was a small problem — Warrior didn't work for WCW at the time. After months of waiting, and literally dozens of people showing up under the mask, they finally made Wrestling/RicFlair the "real" Black Scorpion. The kicker? The Black Scorpion was created to give Sting an opponent ''other than Ric Flair.''
* At one point, ECW Champion Wrestling/{{Christian}} wanted a match on ''Raw'' against WWE Champion Wrestling/{{Sheamus}} in 2010, and as part of his pitch to the guest host about making the match, he joked that he and Sheamus were both born ''without last names''. Knowing [[DeadpanSnarker Christian]], it was possibly part of the joke that this statement ran directly counter to the fact that Sheamus ''O'Shaunessy'' and Christian ''Cage'' both spent years making their names on the independent circuit in their native countries prior to their WWF/E television debuts, upon which said surnames were scrapped.

[[folder:Tabletop Games]]
* ''TabletopGame/Warhammer40000''. The setting is ''deliberately'' designed to take into account the possibility of Continuity Snarl by making the tech [[SchizoTech naturally variable]] and everything told is either [[UnreliableNarrator from skewed viewpoints, propaganda, or possibly inaccurate documents, reports, or histories.]] Its creators' pronouncement is "Everything written about 40k is ''canon,'' but it isn't necessarily ''true.''" The ''Literature/HorusHeresy'' series is an exception to this; the idea is that this is what ''really'' happened, without 10,000 years of distortion.
* Two ''TabletopGame/VampireTheMasquerade'' books came out close together, both revealing that [[BeethovenWasAnAlienSpy Rasputin was a member of two distinct Vampire clans]]. Instead of making one CanonDiscontinuity, it became a RunningGag that Rasputin was everywhere before revealing he was a wraith who possessed several supernatural figures since his death.

[[folder:Theme Parks]]
* In ''Ride/BackToTheFutureTheRide'':
** The original [=DeLorean=] Time Machine makes an appearance sitting in Doc's garage and seems to be in mint condition notwithstanding being destroyed by a freight train at the end of Part III, though it might be possible he simply rebuilt one.
** The Clock Tower seems to be working, even though it was still broken as of October 21st, 2015 in Part II. The ride, however, takes guests 4 days later to October 25th, 2015. Whether or not it may have been "repaired in four days" is up to you.
* During the Dementor attack in ''Ride/HarryPotterAndTheForbiddenJourney'', the Chamber of Secrets is seen in ruins, yet in the second part of ''Film/HarryPotterAndTheDeathlyHallows'' it is seen in an almost perfectly intact state.

* The story detailed in the promo-material for Franchise/{{LEGO}}'s short-lived ''{{Toys/Slizers}}'' line could never agree on what the characters were (Are they single entities? Or entire species?), in what order the {{Elemental Nation}}s on their [[PatchWorkMap planet]] followed each other, or just ''how many'' regions there were at all. This hit the US market harder (where the series was known as "''Throwbots''"), since in their story, there were multiple planets, but in the line's second year, they got replaced by the European single-planet setting.
* Thanks to ''WesternAnimation/{{Mixels}}'' being a toyline by LEGO and a show by Cartoon Network working in tandem with each other, it is bound to get things wrong. This includes personalities of Mixels, and, most divisively, whether Jawg or Gobba is the leader of the Fang Gang (toys say Jawg, series says Gobba).

[[folder:Video Games]]
* There's a rather telling one between ''VideoGame/DeadSpace'' and ''VideoGame/DeadSpace2''; in the first game, the Red Marker is basically portrayed as benign and the key to stopping the Necromorphs, but in the second one, it's the active ''source'' of the Necromorph outbreak. Actually unsnarled (though partially through clue-fuelled deductions) in ''VideoGame/DeadSpace3'': [[spoiler: the Markers broadcast a signal that ''creates'' Necromorphs and, when their numbers reach a critical mass, causes them to amalgamate into a gargantuan alien lifeform called a "Brethren Moon". The constant rephrase of "Make Us Whole" from both of the Markers is them trying to compel enough people to die and become Necromorphs to create a new Brethren Moon. Isaac misinterpreted the Red Marker's pleas in the first game and inadvertently placed it upon a signal dampening device that had been constructed when it was placed there two centuries earlier]].
* ''Franchise/KingdomHearts'' suffers immensely from this. In the very first game, Riku tells Sora that there can't be two Keyblademasters and takes the Keyblade from him. The letter that King Mickey sends to Donald and Goofy also implies that Sora is THE Keyblademaster by telling them to find the one person with the key, but what happens at the end? We see [[spoiler:King Mickey]] with a keyblade of his own Just like Sora's. It doesn't help that while possessed, Riku wields another type of Keyblade and that now virtually everyone in the series has one. One could easily say that he just made a mistake, but that isn't even hinted at.
** Namine is simultaneously both an example and not an example. She was somehow born from Sora's body and Kairi's heart when Sora became a Heartless in the first game giving her power over his memories. Roxas is kinda like her twin, born from Sora's body and heart (and taking on the form of Ventus because his heart was hiding in Sora and it's hinted part (or all) of it stayed in Roxas). The series explains this quite clearly and points out Namine is a special type of non-standard Nobody. This is minor issue until you realize Sora also gets his body BACK within minutes of losing it due to the now restored Kairi's powers as a Princes of Heart, resulting in Roxas getting NONE of Sora's memories, and it's unclear if Namine got any of either of her "parents"' memories. And let's not get into Xion and the fact that she's Sora's memories made manifest while also being a replica of Sora....Yes, the series explains how all this happened quite clearly! But it doesn't explain how any of that CAN happen.
* While the individual ''VideoGame/{{Klonoa}}'' games have decent plotlines, the inter-game continuity gets rather ridiculous. In ''Door to Phantomile'', [[PlatformingPocketPal Huepow]] [[spoiler:is revealed to be the prince of the Moon Kingdom using the Ring Spirit form as a disguise]], ''and'' [[spoiler:is tragically separated from Klonoa at the end of the game]], both of which are ignored when he reappears in later games. Not only does Joka have a different personality in every game he appears in, but he already knows Klonoa in half of them, and is killed in the other half. And Chipple, a random villager from ''Empire of Dreams'', showed up in ''Dream Champ Tournament'', where he had become Klonoa's close friend... and ''a kangaroo''.
* ''Franchise/TheLegendOfZelda'' continuity is very confusing for the simple reason that until ''[[VideoGame/TheLegendOfZeldaSkywardSword Skyward Sword]]'', we didn't have the whole picture, and, of the bits and pieces gotten, weren't told how they fit together[[note]]Before the official timeline was revealed, it was generally accepted that certain games could be grouped together (''[[VideoGame/TheLegendOfZeldaTheMinishCap The Minish Cap]]'' leading into the ''[[VideoGame/TheLegendOfZeldaFourSwords Four]] [[VideoGame/TheLegendOfZeldaFourSwordsAdventures Swords]]'' games, or ''[[VideoGame/TheLegendOfZeldaALinkToThePast A Link to the Past]]'' leading into ''[[VideoGame/TheLegendOfZeldaLinksAwakening Link's Awakening]]'', for example); the problem for fans was sorting these groups into a viable chronology[[/note]], leading to two decades of debate as to how to organize anything. The use of a TimeyWimeyBall in ''[[VideoGame/TheLegendOfZeldaOcarinaOfTime Ocarina of Time]]'' opened up the possibility that {{Alternate Timeline}}s were in play, and WordOfGod itself was contradictory. Franchise creator Creator/ShigeruMiyamoto, not all that concerned about the timeline due to feeling that stories in video games should be peripheral to the experience, [[ExcusePlot if existent at all]], seemed to endorse that the various games may be corrupted retellings of each other. Eiji Aonuma, who joined the Zelda team starting with ''Ocarina of Time'' and became series director shortly after, preferred there be a concrete timeline. Things were finally sorted out in late 2011 when the two laid down an official timeline in the ''Literature/HyruleHistoria'' artbook,[[note]]which, among other things, showed that things split into THREE timelines, not two as was previously thought, explaining why it was so darn difficult to figure out what went where[[/note]] but the confusion ''will'' return anew each and every time a new game is nearing release.
** It should be noted that the official timeline only had slightly fewer problems than the average fan timeline at the time of its reveal. The reason for this ultimately stems from the games always focusing on refining gameplay long before crafting a story to match, games prior to ''Ocarina'' not being made with any overarching timeline in mind, and (arguably) confusion about where to place Creator/{{Capcom}}-developed installments (the ''Oracle'' games, ''The Minish Cap'', and the ''Four Swords'' games). In fact, while 2017's ''Hyrule Encyclopedia'' mostly kept the ''Hyrule Historia'' timeline intact, it did change the placement of the ''Oracle'' games; instead of being direct interquels set between ''A Link to the Past'' and ''Link's Awakening'', they became distant sequels to the latter.
* ''Franchise/MortalKombat''. Each character gets his/her own ending, they often intersect, with other character's endings, and are often in direct conflict with other character's endings, showing one character winning a battle in his own ending, but being killed in the same battle by his opponent in his opponent's endings. Background information in the next game says which endings are canon, and which aren't. The official word on the ''VideoGame/MortalKombatDeception'' endings are [[AllThereInTheManual only on Armageddon's website]]: Basically, [[UnwittingPawn Shujinko]] and [[MagicalNativeAmerican Nightwolf's]] endings worked together to end [[BigBad Onaga]]. For the ''VideoGame/MortalKombatArmageddon'' endings, replace "Background information in the next game" with "Opening cutscene in [[VideoGame/MortalKombat9 the next game]]": Basically, either the backfiring of Taven's plan to KillEmAll empowering everyone instead allowed Shao Kahn to win, or Kahn just flat out won on his own through his sheer power.
** There are more straight examples of snarls in the actual story, mostly the result of the lead writer shift after ''[=MK4=]''. The two which stand out the most are Scorpion's oath to protect Sub-Zero (started in his ''MKII'' ending, supported in the official comic and ''[=UMK3=]'' ending, then ignored completely in ''[=MK4=]'', with following games being ambiguous about the whole ordeal, or portraying him as an AxCrazy [[RoaringRampageOfRevenge revenge-seeker]]), and Kintaro's fate after ''MKII'' (with 3 different sources, all of debatable canonicity, stating different and contradicting fates for the Shokan).
** Another big snarl is that at the end of ''[[VideoGame/MortalKombat2 MKII]]'', Shao Kahn is KilledOffForReal, but in ''3'' [[UnexplainedRecovery he returns alive]] and well to take over the world.
** Yet another headscratcher concerning Scorpion occurs ''because of'' the above WordOfGod statement about Onaga's defeat in ''Deception''. After being thrown into Shang Tsung's Soulnado at the end of ''Deadly Alliance'' and whisked away to heaven, Scorpion made a deal with the Elder Gods: if he became their Champion and vanquished Onaga, they'd revive his dead Shirai Ryu clansmen. In ''Armageddon''[='s=] Konquest Mode, Taven runs into Scorpion, who is furious because the Elder Gods revived the Shirai Ryu as undead abominations. This would suggest they were being dicks who didn't uphold their end of the bargain when Scorpion delivered (as seen in his ''Deception'' ending), but ''that'' would go against Shunjiko being the one to take down Onaga in-canon (with some help from Nightwolf).
* ''Franchise/StreetFighter'': In fairness, a lot of it is because ''[[VideoGame/StreetFighterII II]]'' become an iconic landmark revolutionary sea-changing event of events which changed the universe forever and ever (to the point where pretty much everyone [[CapcomSequelStagnation got plain sick of it]]). If this weren't the case, Creator/{{Capcom}} ''probably'' would've just relished their success and quietly released ''[[VideoGame/StreetFighterAlpha Alpha]]'' as a fun, inconsequential one-off featuring the unselectable fighters in [[VideoGame/StreetFighterI the first game]], then made a full break with ''[[VideoGame/StreetFighterIII III]]''. As it is, ''II'' and its continuity has reached such an enormous Shuma-Gorathian level that it's ''dragged the rest of the ''Street Fighter'' universe into it''. Hence, ''VideoGame/StreetFighterIV''. With Makoto, Dudley, and Ibuki (and now Yun and Yang) at the same age and with the same motivations as in a game that canonically isn't supposed to happen for at least another three years. With a hopelessly convoluted plot involving M. Bison ([[spoiler:who ''does'' die for real [[VideoGame/StreetFighterV eventually]]]]) and a Korean hellion we've never even heard about before. With Adon seemingly stuck in the distant past. With Rose around for no apparent reason. Before, there would be retcons; now, Capcom isn't even trying to hash it out anymore.
** ''[[VideoGame/StreetFighterAlpha Street Fighter Alpha 2]]'' basically treated the SNES ''VideoGame/FinalFight'' sequels, particularly ''Final Fight 2'', as if they never happened. They did so by introducing Zeku as Guy's Bushin Ryu predecessor, ignoring the fact that Genryusai from ''Final Fight 2'' was precisely introduced to fill that role. The ''Alpha'' series continued with no reference to Genryusai's existence until Maki, Genryusai's daughter and a fellow Bushin apprentice, was introduced to the portable versions of ''Alpha 3'', where she was Zeku's other student. The developers didn't bother to explain where Genryusai fits in within the Bushin Ryu hierarchy, but some fans believe that Zeku was actually Genryusai's student.
** Capcom plays so fast and loose with continuity that now we have [[VideoGame/CapcomFightingEvolution Ingrid]], a character who [[ClockRoaches deals with continuity snarls]]. [[CrypticBackgroundReference Maybe]]. Between having few appearances and Capcom's refusal to ever clear anything up, she's more likely to turn into a snarl herself.
* ''VideoGame/{{Myst}}'' created an interesting continuity snarl when it {{retcon}}ned the prison books of ''Myst'' and ''VideoGame/{{Riven}}'' into actual ages. That is, the books themselves were not intrinsically special or different from other linking books. ''VideoGame/MystIV'' goes into great detail as to what the Red and Blue ages (named Spire and Haven) are like. While this works for ''Myst'', it violates the events as they unfold in ''Riven''. To beat ''Riven'', you have to trap Ghen in a prison book. This book was presented as a special "one man prison" book, which is a very important plot point. Ghen's no fool; he isn't going to go into any random book some guy brings him. To ensure it's safe, he asks ''you'' to go through the book first. This works out in the end because it is a ''one man'' prison; when he comes through the book after you, you are freed and he is trapped. If that book were a regular linking book, you'd be trapped with a very pissed-off Ghen... who had the sense to bring a gun.
** [[WordOfGod The official version]] is that that the "[[LiteraryAgentHypothesis real]]" Stranger talked his ([[FeaturelessProtagonist or her]]) way out of it, which the player [[HeroicMime can't really do]].
** It isn't the only retcon in the game's canon that poses problems for ''Myst''. When the official rules for linking books were more clearly established, they included the fact that sound doesn't travel through a linking panel. This means that the stranger couldn't have talked to Sirrus and Achenar, regardless of whether they were in prison books or prison ages, nor could he have talked to [[spoiler:Atrus through the linking book to D'ni at the end of Myst]]. This is compounded by the fact that Sirrus, Achenar and [[spoiler:Atrus]] definitely shouldn't have been able to see the Stranger, as although the linking panel lets you see an Age, you clearly can't see back through a linking panel even inside Myst ([[spoiler:including the D'ni book, since when you get to D'ni you can't see back into the library, so how did Atrus see the stranger?]]).
* ''Franchise/MegaMan'' has a real weird timeline. ''VideoGame/MegaManX'' was supposed to end after ''VideoGame/MegaManX5'', but didn't, leaving a complicated mess of the continuity of its series.
** ''VideoGame/MegaManXCommandMission'' takes place during 22XX, which is when the ''VideoGame/MegaManZero'' series does. Bosses regularly refer to Zero [[UnderestimatingBadassery "Century-Old Junk"]] (literally, not figuratively), and given how the ''X'' series takes place in 21XX, things don't fit, especially considering the time needed for the Elf Wars and such.
*** This discrepancy is explained away by two facts: ''Command Mission'' is a non-canon GaidenGame and ''Zero'' is [[{{Fanon}} commonly assumed by fans]] to occur in 22XX but is actually given no exact date in-series. It's only said that it takes place a century after the Elf Wars, which in turn are set sometime after the currently LeftHanging ''X'' titles.
* ''Franchise/TheElderScrolls'':
** In general, canon and continuity [[UnreliableCanon are almost meaningless concepts]]. Bethesda refuses to invalidate your choices about [[FeaturelessProtagonist who your character is]] and [[WideOpenSandbox what he/she does]]. Therefore, there is no definitive version of the Nerevarine/Champion/Dragonborn, etc. and very few canonized events (the main quest line usually being an exception.)[[note]]According to the developers, "all the quest chains present in the game happen, but not all are necessarily done by the [Player Character]."[[/note]] Additionally, all in-game information, books, and historical records are [[UnreliableNarrator biased]] or otherwise unreliable or contradictory, with the implication that AllMythsAreTrue and everyone is right in spite of the contradictions. From a meta-perspective, canon is complicated by the fact that the majority of the lore that elucidates the nature of the world of Tamriel [[LooseCanon comes from the work of an ex-dev and were written in an unofficial capacity]] after he left the studio. Many lore-scholars within the fandom actually consider his work ''more'' canon than the published games themselves, and the fact that the games [[CanonImmigrant reference and quote these works]] adds to the confusion. Rather than become frustrated, fans tend to ''embrace'' this ambiguity as one of the more fascinating elements of the series.
** These even happen in-universe, with TimeCrash events known as "Dragon Breaks." Essentially, the Dragon God of Time (Akatosh) is tampered with in some way, causing [[CosmicRetcon the reality of the world to change]] in some way. (Mortal beings ascending to godhood or otherwise tapping into some sort of divine power are the most frequent cause.) The "Warp in the West" which [[MergingTheBranches merged]] ''[[VideoGame/TheElderScrollsIIDaggerfall Daggerfall]]'''s MultipleEndings is one of the most famous Dragon Breaks.
* ''VideoGame/{{Touhou}}'': The PC-98 games ''mostly'' seem to have been stricken from canon, but occasionally there'll be a reference to them, leading to headache-inducing attempts by fans to reconcile them with the Windows games. And the setting as described in the first few Windows games doesn't really match later what'd later get nailed down in ''[[AllThereInTheManual Perfect Memento in Strict Sense]]''... which would cause problems itself when the things it covered that weren't in existing games would turn out different when they actually appear.
** The major, not really {{handwave}}able problem is the Lunar Wars. ''Imperishable Night''[='s=] backstory is centered around a war between Earth and the Moon (covered up by the Apollo 11 moon landing), and [[MoonRabbit Reisen]]'s desertion of the Lunarian army and subsequent escape to Earth form part of the game's main plot, since the Lunarians want her back. Then ''Bougetsushou'' comes along and suggests that the Lunarians just mistook the Apollo 11 landing for an act of invasion and got militarized out of paranoia (as well as causing the Apollo 13 incident by shooting at the rocket), meaning there ''were'' no "Lunar Wars". If this is true, it begs the question of why exactly Reisen fled to Earth in the first place.
* The Blaze/Silver/Eggman Nega issue in the ''Franchise/SonicTheHedgehog'' series. In ''VideoGame/{{Sonic Rush|Series}}'', Blaze is from an alternate dimension. In ''[[VideoGame/SonicTheHedgehog2006 Sonic '06]]'' she is from the future (and seems out of character). And the events of ''Sonic '06'' were erased from the timeline in that game's ending, making things more confusing. Additionally, due to that fact she was from the future, she could be REAL version of Blaze, who isn't born until later. The other one DID come from an alternate universe...
** Later on, in the DS version of ''[[VideoGame/SonicColors Colors]]'' (which may or may not be canon), Blaze appears alongside Silver during the third mission on Sweet Mountain and, should the player receive an S rank in their side mission, after a battle with [[ThoseTwoBadGuys Orbot and Cubot]] Silver claims to have felt like they'd fought together before, a nod to ''[='06=]'' Blaze (who was Silver's best friend). Tails comments that perhaps they had been partners somewhere, some time.
** And ''then'' there is ''[[VideoGame/SonicGenerations Generations]]''. Blaze is first seen at Sonic's birthday party interacting with Cream and her in-game character profile notes that she's from another dimension, indicating that this is the same Blaze from ''Rush''. As a ContinuityNod ([[ResetButton of sorts]]) to ''[='06=]'', Blaze is found in Crisis City. Here's where things get wonky. After Sonic completes the Crisis City Act 2 mission "Blaze: Piercing the Flames," Blaze will remark, "I never thought I'd find myself in Crisis City again," bringing up the question of ''how'' exactly Blaze knew of a place that existed in a timeline that was ''erased from history''.
** Additionally, both Silver and Eggman Nega (characters with prominent ties to Blaze, but connected to her by different games) are drawn into this snarl as well, as the two appear in the ''Rivals'' series -- ''sans'' Blaze. Here, Silver is still from the future, but Nega (established in ''Rush'' as Eggman's parallel self from the same dimension Blaze is from) is now a ''descendant'' of Eggman, embittered by how Eggman's failures have tarnished the family name in the future and is now an ''enemy'' of Eggman instead of working with him. Later on, Nega reappears in ''Rush Adventure'' and ''Rivals 2'' with the conflicting backstories of his appearances between ''Rush'' and ''Rivals''. It's implied that, due to ''[='06=]'' slamming down on the ResetButton until it ''cracked'', Silver now hails from the ''Rivals'' future and Blaze is from ''Rush'' (with no official word on Nega with his lack of appearances since), but Silver is still the Rival Battle for the Modern era of ''Generations'' (which takes place in Crisis City, no less) and [[spoiler:the ending of ''Generations'' has him and Blaze briefly chatting it up before everyone says their goodbyes to Classic Sonic and Tails]].
** The confusion was finally cleared up in 2012, with Takashi Iizuka stating that Blaze is from an alternate dimension, while Silver and Eggman Nega are from the future.
** In ''VideoGame/SonicForces,'' Tails instantly recognizes Classic Sonic as an alternate universe counterpart to Modern Sonic, rather than explicitly being his time displaced younger self like ''Generations'' portrayed him as.
* Ironically, ''VideoGame/SuperRobotWars'' successfully averts this, despite being a MassivelyMultiplayerCrossover. In fact, developer Banpresto does the inverse by snarling continuity together. Currently, the "[[FanNickname Classic Timeline]]," ''VideoGame/SuperRobotWarsAlpha'' and ''VideoGame/SuperRobotWarsOriginalGeneration'' series have several common ties via characters being the same individual throughout these continuities ([[spoiler:Gilliam Yeager and Cobray Gordon]] head the list).
** Odder still when you realize these continuities were originally to be in its own {{Canon}}, and these characters were only giving out {{Continuity Cameo}}es, but ''Original Generation'' is in the position of tying nearly every Banpresto-developed game into an interlocking [[TheMultiverse multiverse]] courtesy of these entities referencing their own appearances from those canons.
*** Additionally, this applies to one licensed character: it's strongly implied [[Anime/NeonGenesisEvangelion Kaworu Nagisa]] in all his appearances throughout ''Super Robot Wars'' (''[[VideoGame/SuperRobotWars4 F/F Final]]'', ''Alpha'', ''[[VideoGame/SuperRobotWarsMX MX]]'' and ''[[VideoGame/SuperRobotWarsZ Z]]'') is the same Kaworu or his consciousness surfing across dimensions with full knowledge of his history (in ''Alpha 3'', he vaguely refers to the events of ''MX'', while in ''Z'' [[spoiler:he laments the fate of the ''MX'' world, which is loosely implied to be set before ''Z'']]).
* The creators of ''VideoGame/WorldOfWarcraft'', after admitting they had forgotten a key fact about the eredar that was established in ''VideoGame/{{Warcraft}} III'''s [[AllThereInTheManual manual]], went on to say that they didn't care about continuity as much as making a good game and brushed off complaints about the changes made to the draenei. Eventually, fans learned to ignore this and some other minor {{retcon}}s.
** The draenei retcon was fairly minor in terms of effects to storyline (the draenei didn't have much involvement in it before), although it did retcon the background of Sargeras somewhat. To make matters confusing there are actually two new explanations for his corruption: one being the same as the old one but with the eredar replaced with demons in general, and the other being that he just came to perceive the universe as flawed, with no mention of demonic corruption. Nobody is quite sure which is canon, although the evidence would lean towards the latter one. Years later, demons in general are confirmed to pre-date Sargeras' corruption once again, though it varies by race. ''Warcraft Chronicle'' ended up complicating things even further by saying that ''neither'' explanation is really true. According to the new explanation, the true cause of his corruption was the horror of learning that a newly-introduced force called the Void Gods is trying to exterminate all life in the universe and that there's nothing that can be done to stop them.
** The real Snarl (which was thankfully sorted out) was the origin of Garona, a half-orc and a fairly important figure in lore. She originally had orc and human parentage, and was born before the orcs launched their first major invasion (originally there was quite a bit of time between the opening of the Dark Portal and the First War, during which the orcs mainly did small raids on the human settlements nearby the Portal). However when the First War was retconned to have happened almost immediately after the opening of the Portal, there was no way for her to be half-human. Then she was half-draenei, a human-like race from Draenor. Then the draenei were ugly creatures that looked in no way human. Then the draenei were mutant human-like creatures. The the un-mutated draenei were non-demonic eredar (see above). Her parentage went unexplained for years and for some time it seemed that she was simply going to be erased from continuity, but she was finally given a new origin, making her a product of the warlock Gul'dan's experiments that involved breeding draenei prisoners with orcs, and then making them grow rapidly into maturity with magic.
** Blizzard introduced a new one with their whole "There must always be a Lich King" thing, although they still have time to justify it. The idea is that if no one takes over the job as Lich King, then the Scourge will overrun the world and destroy everything. There's two problems with that. One: There can't be that many Scourge left, since we've fought and destroyed them all the way to the Lich King's very doorstep. Two: We've already seen what happened when the Lich King loses power without a successor, it was the ''entire plot'' of the Warcraft III expansion, the Frozen Throne. The Lich King was dying due to a spell that Illidan cast, but he was interrupted before he could finish. As Arthas rushed over to Northrend to take over, the Scourge did ''not'' overrun the world. In fact, they started to become the Forsaken, who are supposed to have their minds back. Thus, if we assume that the new revelation is true, it not only makes Illidan look like a big fool (even bigger than the heroes who trusted Maiev), it implies that the Forsaken are an evil more dangerous than the Scourge. Although the Wrathgate event and subsequent invasion of Undercity make this a very good possibility, the Forsaken are a playable race and it seems doubtful that the game will ever truly confront or resolve this problem. Even so, not all Forsaken are evil, and the evil ones are not unstoppable (just a playable race, and full of plot armor).
*** The leading fan theory is that it might actually have to do with the Elder/Old Gods, which the Nerubians used basically live over, and the Lich King might technically be accidentally keeping it sealed. Scourge boosted by the power of Eldritch Abominations might be... bad. Very Bad. Considering that Yogg-Saron, god of death, very loudly screams about how the Lich King is trying to usurp his throne, this seems like the most likely explanation. Note that Yoggy was still sealed when the Forsaken were freed, which explains why they kept their minds instead of being re-enslaved by him.
*** However, WordOfGod during an Ask Creative Development Q&A says that the "There must always be a Lich King" statements should be taken at face value. No Old Gods, no Ner'zhul speaking through trusted ghosts... just a need for a new Lich King, with the added bonus that Arthas or Ner'zhul could have unleashed the Scourge and ravages Azeroth without the undead being feral. Arthas likely held them back to corrupt people to maintain his pride (to show that his failings were normal). Why not Ner'zhul? No idea. Probably to buy time to escape the Legion's control.
** Blizzard lampshaded their tendency to do this with the Well of Eternity dungeon, which revisits a previously established moment in Warcraft lore using time travel. Defeating the last boss under the wrong circumstances grants the achievement "That's Not Canon!" with an angry face as the icon.
** Previous lore stated that the only life on Azeroth before the Titans came were the elementals, and the Old Gods that they worshiped, both of which were imprisoned by the Titans before they shaped the world. At some point, the Earthen were exposed to the Old Gods, which turned them into mortal dwarves. Now, a titan computer known as the Tribunal of Ages says that during the shaping by the earthen the Old Gods came to Azeroth and corrupted it, including using the Curse of Flesh, followed by the titans coming. Supplemental materials say that other life existed before the titans came, including trolls, the evil insectoid races, and the faceless ones. Also (as a sub-snarl that is pointed out by the source) the tauren, but before their creator Ancient (the Bull Ancient) could have existed (no Emerald Dream/nature to be spawned from). The Klaxxi confirm that the insectoids (the aqir) were around before the titans, when previously it was just the elementals.
** ''Literature/WorldOfWarcraftChronicle'' was written to clarify a lot of the Snarl, especially ones related to the Titans/Old Gods, which include writing off the Tribunal of Ages as a [[UnreliableNarrator forgery]] and giving all life on Azeroth a titanic origin.
* The ''[[Franchise/ShinMegamiTenseiPersona Persona]]'' titles have generally been implied to take place in the same universe, despite great differences between the first three games (actually two, but one is a two-parter) and subsequent ''Persona'' games. This is because both games in the aforementioned two-parter, ''VideoGame/{{Persona 2}}'', end with a massive CosmicRetcon, the second of which may have reset everything from [[VideoGame/{{Persona}} the first game]] as well. This is made even more confusing by the fact that the later games make several [[ShoutOut Shout-Outs]] to the original two/three in the forms of former playable characters being mentioned on TV or by other characters. In addition, the nature of the standard enemies do not remain consistent; P1 and P2 have them manifesting as sapient demons, ''VideoGame/Persona3'' and ''VideoGame/Persona4'' have them manifesting as feral "Shadows", and ''VideoGame/Persona5'' splits the difference, with the enemies taking the form of sapient demons but being referred to as Shadows.
** The portrayal of the Shadows themselves is inconsistent. For example, while ''VideoGame/Persona4'' portrays Shadow Selves as being their "real" counterparts' untamed Personas, ''VideoGame/Persona2'' portrays them as capable of existing even if their counterparts already have their Personas. There are even inconsistencies between ''VideoGame/Persona3'' and ''Persona 4'' (which [[WordOfGod definitely]] share the same universe); the ''Persona 3'' Club Book states that shadows are fragments of Nyx that exist inside all humans, while ''Persona 4'' (re)establishes them as products of the human psyche (which carries through to ''VideoGame/Persona5''). That said, most of these differences could be chalked up to the individual influence of each game's main supernatural antagonist.
** Even the details regarding the eponymous Personas themselves constantly change:
*** While P1 and P2 indicate that you have to first perform a certain ritual before you have the power to summon a Persona, P3 implies that most Persona users are simply born with it, P4 has its characters obtain them by simply accepting their Shadows, and P5 shows them as being obtainable by anyone who visits the Metaverse.
*** While P2 indicated that all Persona users can summon their Personas in the physical world without any technological assistance, subsequent games portray most Persona users as needing an Evoker to summon their Personas when they're not inside the collective unconsciousness.
** ''VideoGame/Persona4Arena'' directly contradicts ''Persona 3'' and ''Persona 4'' with the characters' choices of Personas. All of the ''Persona 4'' characters are stuck with their Initial Personas, despite the game referencing Chie and Yosuke’s completed Social Links (meaning they should have their Ultimate Personas instead), and too little time has passed for them to have regressed. Teddie is the most glaring example as his Star Social Link is one of three that levels up automatically in ''Persona 4'' and must be completed in order to reach the True Ending (which ''Arena'' explicitly follows). Even more confusing is Aigis, who has Pallas Athena even though in P3's "The Answer" [[spoiler:Aigis inherits the P3 protagonist's Wild Card and Pallas Athena is changed into Orpheus. "The Answer" is clearly canon because Erebus appears in Elizabeth's story and Aigis is stated to possesses the Wild Card. It is unlikely that Aigis was able to re-fuse Pallas Athena since Igor tells Aigis that she has the access to the same number of Personas through the Wild Card as her predecessor did]].
** Adding to the confusion, while this surprisingly obscure [[http://www.1up.com/do/feature?pager.offset=1&cId=3172364 interview]] with ''Persona 4'''s staff indicates that the games ''do'' all take place in the same verse, ''[[AllThereInTheManual Persona Magazine]]'' (which began publishing sometime after the 1UP interview) often ignores ''P1''/''P2'' continuity and referred to the current Persona-verse as "the ''P3''/''P4'' world".
* ''Franchise/{{Halo}}'''s canon policy that "new > old" naturally results in a lot of these.
** The universe can't make up its mind on whether there was a single "[[ChildSoldiers class]]" of [[SuperSoldier Spartan-IIs]] or more. The various writers have changed the answer to that question more than ''nine times'', which is summed up at [[http://xbox.answers.wikia.com/wiki/Was_there_a_second_class_of_Spartan-IIs this Wikia Wikianswers page.]]
** ''Literature/HaloTheFallOfReach'' established a very precise timeline for the titular battle. And then ''VideoGame/HaloReach'' came along and ruthlessly snarled it up, so much so that the timeline issues ''still'' haven't fully resolved despite ThreeFourThreeIndustries' best efforts.
** Forerunner/Flood-related lore is rife with this, even though ''Literature/TheForerunnerSaga'' made a pretty decent effort to reconcile Creator/{{Bungie}}'s and Creator/ThreeFourThreeIndustries' respective portrayals, with the canon explanation being that any information that gets retconned away had come from an UnreliableNarrator or [[UnreliableExpositor Expositor]]. Most notably, early lore strongly implied that humans were the Forerunners' direct descendants, before later media changed them into two separate but probably-related species. Other examples included the vastly different portrayals of [[spoiler:the Didact]] (which were only reconciled by revealing there were ''two'' of him), the revelation that most Forerunners actually disliked humanity despite previous media establishing the latter as the designated "Reclaimers" to the former's legacy, the shifting timeline of when the Forerunners first became aware of the Flood, and whether the motivations of ancient humanity's attempt to conquer Forerunner worlds leaned towards those of InvadingRefugees merely seeking to replace colonies lost to the Flood or those of [[WellIntentionedExtremist Well-Intentioned Extremists]] trying to halt the Flood's spread.
** See also ''Film/HaloNightfall'' under Film.
* While early ''Fanchise/{{Pokemon}}'' games' differences between "Generation" versions are mostly aesthetic, later years significantly change the plot and in ''VideoGame/PokemonRubyAndSapphire'''s case, who the main antagonist is. Then there's whether the original releases of a generation are canon, or if only their respective [[VideoGameRemake remakes]] are.
** ''VideoGame/PokemonBlackAndWhite'' has even ''more'' differences between the two versions than previous games, although it is implied that both versions take place in parallel dimensions of each other that are able to interact with each other (trading, player battles and the Entralink).
** Continuity in ''Pokémon'' games is usually thought of as being based on how the Pokémon themselves are traded from game to game, but this can get a bit confusing when you factor in ''VideoGame/PokemonColosseum'' and its sequel, ''VideoGame/PokemonXDGaleOfDarkness''. The latter takes place five years after the former, but both games are only compatible with the GBA games, which are assumed to take place at the same time. The Gen 4 games (the Sinnoh-based games and Johto-based remakes) take place three years after the GBA games (the Hoenn-based games and Kanto-based remakes). The ''Black and White'' games take place further into the future (Since an [=NPC=] from the Gen 2 games/Gen 4 remake settled down and now has a school-aged child, it's thought to be at least 5 to 8 years) and their direct sequels are set 2 years after. ''VideoGame/PokemonXAndY'' are thought to take place at the same time as ''Black 2 and White 2''.
** This gets even more pear-shaped if you decide to consider the spin-off titles. Depending on the title in question, it can be canon with the main games (''[[VideoGame/PokemonSnap Snap]]'' and ''[[VideoGame/PokemonRanger Ranger]]'') or it exists in completely different continuities (''[[VideoGame/PokemonMysteryDungeon Mystery Dungeon]]'', ''[[VideoGame/PokemonTradingCardGame TCG]]'', ''VideoGame/HeyYouPikachu'' and its spin-offs, etc.).
** ''[[VideoGameRemake Omega Ruby and Alpha Sapphire]]'' can't seem to decide where they fall in the continuity. On the one hand, they're explicitly stated to take place before ''VideoGame/PokemonBlackAndWhite'' and ''VideoGame/PokemonXAndY'' (the latter of which is concurrent with ''VideoGame/PokemonBlack2AndWhite2''), which would put them at the same time as [[VideoGame/PokemonRubyAndSapphire the originals]] (parallel to the Kanto games). However, there are a lot of {{Mythology Gag}}s to the original ''Ruby/Sapphire'', which explicitly point out a ten-year gap (such as an NPC mentioning how Pokémon Centers had a second floor 10 years ago). Some believe they imply a ContinuityReboot for the entire series, with the existence of Mega Evolution as the [[ForWantOfANail nail]].
*** To make it worse, ''Omega Ruby/Alpha Sapphire'' have the Battle Resort, in which it is implied that the Battle Frontier is planned to be built. Thus it should take place before ''Emerald'', where there is a Battle Frontier on the same island.
*** A bonus conversation in ''Omega Ruby and Alpha Sapphire'' will have Steven refer in vague language that one time he fought alongside Alain and his Mega Charizard — as he did in the ''Mega Evolution Specials'' from the anime canon. You need to be quite an impressive contortionist to reconcile those canons.
*** The postgame segment also all but states that the remakes take place in an [[AlternateUniverse alternate timeline]] from the originals, and that the portal the scientists were planning to send the meteor through would have sent it to the universe containing the original games (which would not have had the means to deal with the meteor). The [[ForWantOfANail nail]] is not Mega Evolution itself, but [[spoiler:the firing of AZ's ultimate weapon--which ran on the "Infinity Energy" that induces Mega Evolution--three millennia prior to the events of ''X/Y'']].
** ''VideoGame/PokemonSunAndMoon'' adds another twist to the mix. It's supposed to take place roughly 2 years after ''X and Y'' on the "Mega Timeline", but there are some oddities here and there:
*** In the post-game you encounter and battle [[PreviousPlayerCharacterCameo Red and Blue]] who are now re-designed to appear in their twenties, but you're also able to battle Wally (or rather his Omega Ruby and Alpha Sapphire incarnation) but he still appears to be 10 years old.
*** The appearance of [[spoiler: Anabel]] in the post-game. During the Ultra Beast sidequest, it is revealed that [[spoiler: she's the same Salon Maiden Anabel from the ''Emerald'' exclusive Battle Frontier... The one that was never built in ''Omega Ruby and Alpha Sapphire''. This Anabel somehow appeared from an Ultra Wormhole and ended up in Alola in the "Mega Timeline" with few memories of her former life]]. This raises a few questions on where 3rd versions (Japanese Blue, Yellow, Crystal, Emerald and Platinum) lie in the continuity.
*** The demo for ''Sun and Moon'' allows you to obtain a Greninja, but this is no ordinary Greninja as it can transform into the previously anime-exclusive [[SuperMode Ash-Greninja]]. The implication that this Greninja used to belong to Ash from the ''Anime/{{Pokemon}}'' anime has raised a few eyebrows.
*** Lastly, ''VideoGame/PokemonRedAndBlue'' have been released on the UsefulNotes/VirtualConsole and the Pokémon obtained in these games can be transferred to ''Sun and Moon'' via ''Pokémon Bank''. Making the original Gen 1 games compatible (and therefore canon) with the rest of the series from Gen III onward. Later releases of ''VideoGame/PokemonGoldAndSilver'' for the Virtual Console would also bring the original Gen 2 games into the mix as well.
** ''VideoGame/PokemonUltraSunAndUltraMoon'', which are kind of the third version but not quite (since it's still a pair of games rather then a single definitive version of the generation) is another kettle of fish entirely. This game is considered to be an "alternate retelling" of the base Sun and Moon games. It starts off similarly, but it veers off the rails here and there:
*** The biggest difference is the appearance of the Ultra Recon Squad, a group of [[spoiler: {{Human Like Alien}}s]] who come from Ultra Space. [[spoiler: Necrozma, who is a Pokémon that comes from Ultra Space (or their part of Ultra Space) is threatening to consume all the light in the universe. Necrozma eventually takes over as the main antagonistic force in these games rather then Lusamine.]]
*** The postgame features a different side story: Episode Rainbow Rocket. [[spoiler: Using Ultra Wormholes, Team Rainbow Rocket is comprised of all the Team Leaders from the past main games who come from universes where they won, all lead by Giovanni. This includes Maxie and Archie, who have their original ''VideoGame/PokemonRubyAndSapphire'' designs as opposed to the "Mega Timeline" versions.]]
*** Ultra Space is more explorable [[spoiler:It's made up of both distant planets, {{Alternate Dimension}}s and {{Alternate Universe}}s, including one that's a version of Hau'Oli City that's been [[ApocalypseHow hit with a nuclear meltdown]].]] You can also find regular Pokémon and Legendary Pokémon from past games in these Ultra Spaces, but no explanation is given as to how they got there.
* ''VideoGame/{{Okami}}'' may only be a 2-game series, but it has one thing it can't agree with itself on. ''VideoGame/{{Okamiden}}'' introduces Akuro, who is the BigBad of the game. Now, dialogue when he's introduced heavily implies that he is the successor of the previous game's BigBad, Yami. But later, the Knowing Jewel claims that he merely used Yami as a vessel. Keep in mind that Akuro didn't exist in the first game, and that both of these versions of what Akuro is come from the ''same game!'' Jeez!
* ''VideoGame/{{Mabinogi}}'' has this, much to the ire of some of the community.
** In Generation 11, you're told that the Shadow Realm was created [[spoiler:out of the grief of Price Tuan]]. Cichol reveals in Generation 16 that [[spoiler:it's the fault of the Soul Stream]]. The Soul Stream is also responsible [[spoiler: for the desolation of Metus and the Beach of Scathach]].
** Cichol also says that [[spoiler:the desolation of Another World was also caused by the Soul Stream]]. Upon arriving to Another World in Generation 1, under the pretense that you're going to the fabled paradise of Tir Na Nog, Dougal ([[AndIMustScream the only one there]]) tells you that it is another world destroyed by the Fomors.
*** FridgeLogic is also demonstrated here. You're told before you head for Another World that [[spoiler: Nao can't help you there (pretty much saying that you can't be revived by her) because Another World is outside of Erinn's Soul Stream (where she resides)]]. ''How is it, then, that a Soul Stream of one world would affect another that's not under the aforementioned Soul Stream?''
** In Generation 4-8, you learn that the Elves and Giants are [[spoiler:beings cursed by Irinid (Neamhain) herself]]. As per the renewal of Chapter 1, Elves and Giants can now participate in the quests in order to obtain their transformations instead of doing the string of quests they originally had in order to obtain their transformations (which were actually removed). Most of the focus of becoming the [[SuperMode Paladin]] was on making the actual armor to go on the journey to obtain the spirit that will enable the Milletian to become the Paladin at will (with a time limit). When the Milletian actually does transform, they wear the armor that they journeyed to create. Elves and Giants ''do not''. They still become the Falcon (if you're an Elf) or the Savage Beast (if you're a Giant). In addition, the skills respectively are still called "Fury of Connous" and "Daemon of Physis," respectively. [[FridgeLogic One begins to wonder why Morrighan would send beings cursed by her sister to get blessed behind said sister's back, and how they just happen to transform differently from the humans.]]
* As new teams were signed by Creator/{{Konami}} to work on new ''Franchise/SilentHill'' entries, the nature and inner workings of the nightmare, as well as mythology behind the titular town, changed considerably.
* ''VideoGame/BatmanArkhamSeries'':
** ''VideoGame/BatmanArkhamOrigins'' caused one within ''itself'' when they [[NamedByTheAdaptation decided to give]] ''ComicBook/BatmanYearOne'''s corrupt S.W.A.T. officer Branden a first name: his bio in the game proper is listed as "Howard", but according to a radio transmission the player can listen to on the Cryptographic Sequencer in the "Cold, Cold Heart" DLC, his first name is "Scott."
** ''VideoGame/BatmanArkhamUnderworld'' sees Harley Quinn in her ''VideoGame/BatmanArkhamAsylum'' costume--which she stated in that exact game was new and a tag at the start of ''Underworld'' says the game takes place "9 years ago", which given ''VideoGame/BatmanArkhamKnight'' states the events of ''Origins'' takes place ten years before it, means part of ''Underworld'' takes place not long after ''Origins''.
* ''VideoGame/TheSims'' has suffered more and more continuity errors with each new installment of the game.
** Between ''VideoGame/TheSims1'' and ''VideoGame/TheSims2'', Michael Bachelor was revealed as Bella Goth's brother, and apparently switched birth order: he was fresh out of college in the first game, while Bella was married and had a child; but in the second game, he appears on the family tree as older than Bella and his ghost shows that he died of old age.
** In Strangetown, Lola and Chloe Singles are shown as twins in one of the family photo albums, but are several days apart in age.
** In Veronaville, the birth order of the Capps is notoriously confused. While Cordelia is named by her father's memories as his youngest child, the family tree names her as oldest. A generation down, the family tree, Consort Capp's memories, and the memories of the siblings themselves place the birth order of Cordelia's children as going either Juliette, Tybalt, Hermia; Tybalt, Juliette, Hermia; or Juliette, Hermia, Tybalt. On the other side of the family feud, Bianca Monty is shown in the family tree to be older than Antonio and Claudio, but Antonio starts off older than Bianca. Isabella Monty also has no memories of the births of her children.
** Between ''VideoGame/TheSims2'' and ''VideoGame/TheSims3'', Kaylynn Langerak went from being much younger than Mortimer and Bella Goth to being slightly older than them. Additionally, Mortimer went from being apparently older than Bella to being exactly the same age as Bella.
** ''VideoGame/TheSims4'' pulls an outright {{Retcon}} on the backstory of the Caliente sisters, turning their mother from Nighat Caliente, who died when they were children, to Katrina Caliente, who is raising them as a single mother. Additionally, the devs have stated that [[TheCasanova Don Lothario]] has a crush on Katrina Caliente, which means that between games he became older than the Caliente sisters, who were exactly his age in Sims 2.
* ''VideoGame/MetalGearSolid'' originally started off as a direct sequel to the events of [=MSX2=] games ''VideoGame/MetalGear1'' and ''VideoGame/MetalGear2SolidSnake'' with a few slight retcons, but as the series went on the retcons started piling up. Most notably with ''VideoGame/MetalGearSolid3SnakeEater'', which contradicted most of the backstory that was established in ''Metal Gear 2'', specifically Big Boss's military history prior to the MSX games (including the moment when he lost his eye) and his age (previous games established he was born during the 1920s, when he wasn't even 30 yet in 1964).
* There are several inconsistencies across the ''VideoGame/{{Diablo}}'' series, although most players pay so little attention to the story that they won't realise it.
** It is said that Mephisto, along with Baal, was originally captured in the desert near Lut Gholein, and later moved to Kurast. In the ''VideoGame/DiabloIII'' timeline it says: Mephisto is captured near the jungles of Kehjistan.
** It is said that the Ancients are the spirits of the Nephalem, the Ancient Ones. But the Arreat Summit (the official ''[[VideoGame/DiabloII DII]]'' webpage) says that they were barbarians chosen by the Ancients.
** The writings of Abd al-Hazir say that the Tristram Cathedral was built around 912 over the vault where Diablo was imprisoned, but Diablo hadn't even been exiled to Sanctuary at that time.
** The ''Diablo 1'' manual says that after their exile the Three Brothers ravaged the lands of the Far East for countless centuries, but in the game it is stated that they did so for decades. In the current timeline 50 years pass between their exile and capture.
** Before he came to Khanduras Leoric was originally a northern lord, this has been changed to an eastern lord.
** In the ''Sin War'' [[ExpandedUniverse trilogy of novels]] the robes of the order of Dialon are azure, they should be crimson. While the robes of the order of Mephis should be azure instead of black. (To match the color of their Soulstone)
** There are many errors in ''Scales of the Serpent'', where the statue of Dialon has a hammer instead of tablets and where the one of Bala has tablets instead of a hammer.
** In ''Scales of the Serpent'', the high priest of Dialon is named Arihan and is said to have had his title for a long time, but in ''Birthright'' all the high priests are named (Malic, Herodius and Balthazar) and Arihan isn't part of them.
** Abd al-Hazir mention that Zoltun Kulle was a Vizjerei mage and as evidence cites the Demonicus de Zoltun Kulle. In the Book of Cain, Cain suspect Zoltun was an Ennead mage.
** There's even something of a continuity snarl between Diablo II Classic and Lord of Destruction. The cinematics of Diablo II Classic say that Diablo was defeated for a while (long enough for the news to reach Marius, at least) before Baal found Marius, took his Soulstone back, and burned the asylum down. But in Lord of Destruction, Tyrael says that while the hero was fighting in hell, i.e. ''before'' Diablo was defeated, Baal had been rallying his army and launching his assault on Mount Arreat, and had already taken over all but one of the barbarian strongholds; and Baal had already recovered his Soulstone by the time he had taken over Sescheron in the opening cinematic in Lord of Destruction. So... did Baal get his Soulstone back before or after Diablo was defeated? [[spoiler: The [[http://diablo.wikia.com/wiki/Timeline official timeline]] rectifies this snarl: Diablo was defeated in late 1264, and Baal began his assault on Mount Arreat in early 1265, retconning Tyrael's statement and undoing the retcon on Marius' story.]]
* ''VideoGame/{{Gradius}}'' has given fans attempting to construct a coherent timeline for the franchise many headaches. Especially for the spin-offs, which are usually dated as "X years since the war against the Bacterions" when there have been no fewer than ''six'' such wars. And that's not even counting trying to incorporate the ''VideoGame/{{Otomedius}}'' spin-offs into the primary timeline (the franchise is unclear as to whether or not ''Otomedius'' is an AlternateContinuity).
* ''VideoGame/TalesSeries'': Demons are... Drastically different between ''VideoGame/TalesOfSymphonia'' and ''VideoGame/TalesOfPhantasia'', and ''VideoGame/TalesOfSymphoniaDawnOfTheNewWorld'' does not help matters despite being an attempt at reconciling any inconsistencies between the two games but managed to bungle this point further. The game flat out stating demons are allergic to mana... Despite the presence of several demonic spirits in ''Phantasia'', which are ''made'' of mana as a rule. Demons are also neutral at worst in Phantasia, willing to help save the world provided they are approached with the right pact ring like any other spirit, whereas in both Symphonia games they are implied to be an AlwaysChaoticEvil race.
* ''VideoGame/FiveNightsAtFreddys4'' has two. First this is the game that shows [[spoiler: the Bite of '87]] and so should take place in 1987, but there are also hints that it takes place in 1983 instead. The second revolves around The Puppet - an animatronic responsible for most of the other animatronics in the series been haunted. The fourth game implies that the ghost that haunts The Puppet is [[spoiler: the victim of the Bite of '87]] but The Puppet is active in ''VideoGame/FiveNightsAtFreddys2'' which seems to take place just before [[spoiler: the Bite]]. Then again, see the first point about when the fourth game is set.
* ''VideoGame/KnightsOfTheOldRepublic'' is set 40 years after the ''ComicBook/TalesOfTheJedi'' comics, yet have very little to do with them, to the point where Jolee Bindo would have married his secret wife during a period where open marriage in the Jedi Order was common.
* The treatment and statements about power armor in its various models in ''VideoGame/Fallout4'' creates a number of problems with continuity. Previously it had been established that the Brotherhood of Steel uses power armor models T-45 and T-51, which were both developed before the war. The Enclave has their own [[VideoGame/Fallout2 more advanced power armor]] (later designated X-01) which they explicitly developed after the war. Then ''Fallout 4'' states that the X-01 is ''also'' from before the war, ''and'' introduces another pre-war model, the T-60, which is somehow slightly superior to even the X-01. There is an attempt to HandWave this by saying that the X-01 was in prototype stage before the war, and Enclave finished it, ''more than 150 years later''. Another new oddity about the power armor is that they now require fusion cores for power, which can only run a power armor for about ten in-game hours at moderate activity, whereas in earlier games they were explicitly stated to have their own fusion reactors.
* The Nibelheim incident in the ''Compilation of VideoGame/FinalFantasyVII''. The original game alone provides about three different versions of the event because of the poeple involved [[spoiler:Cloud's memories are messed up, Sephiroth deliberately manipulates him and Tifa doesn't know all the details]]. While at some point we DO get what seems to be what actually happened, when the other parts compilation retell the events each version is different and multiple details don't match up. For example in ''[[Anime/LastOrderFinalFantasyVII Last Order]]'' [[spoiler: Sephiroth deliberatly jumped into Mako shaft]] while every other version has [[spoiler:him thrown into it by Cloud]], while ''VideoGame/CrisisCore'' has Genesis present during the events, something that doesn't happen in any other version.
* The VideoGame/StarRevenge series of VideoGame/SuperMario64 ROM hacks. Seriously, just [[https://drive.google.com/file/d/0Bzs1FL5re-t2R3JtbG5lSFFUTXc/view look at this]]. A lot of the confusion comes from remakes of the games having different stories than the original and the story splitting between both versions. Also, TimeTravel is involved. The timeline is a mess and that picture even {{Lampshades}} it. [[note]] Furthermore, notice how [=SR6.9=] happens multiple times[[/note]]
* ''VideoGame/RWBYGrimmEclipse'' contains a few contradicting elements which make it impossible to fit in ''WebAnimation/{{RWBY}}'''s timeline. Yang [[spoiler:still has both her arms]] and Pyrrha [[spoiler:is still alive]], which would place the events of the game during or before Volume 3. However, Jaune [[spoiler:has awakened his semblance]], which would place the game sometime after Volume 5. Volume 5 (or 4, or that matter) wasn't even out when the game was released, making the latter point a case of EarlyBirdCameo.

[[folder:Visual Novels]]
* The UsefulNotes/NintendoDS UpdatedRerelease of ''VisualNovel/PhoenixWrightAceAttorney'' featured an extra, fifth case which takes place in between ''Ace Attorney'' and ''Justice For All'' [[spoiler: as evidenced by Maya still being away at Kurain Village training]] wherein Phoenix and Edgeworth work together to assist Ema and Lana Skye in their legal case. However, when Edgeworth reappears in ''Justice For All'''s fourth and final case, Phoenix claims not to have seen him since [[spoiler: the fourth case of ''Ace Attorney'' where Miles was accused of murder]] and Edgeworth supports this by claiming to have left the country right after said events; neither of them seeming to remember their work together on the Skye trial. This could simply be explained away as a case of CanonDiscontinuity by stating that the fifth case of ''Ace Attorney'' never really happened in the series proper, due to it being an addition for the remake. But, Ema is integrated with the official continuity in [[FanNickname the Apollo Justice arc]] by having her appear and explain Wright's involvement with her sister's case, thus making Phoenix's and Edgeworth's reactions to each other in ''Justice for All'' seem odd in retrospect.
** It's quite easy to make it fit in canon if you ignore the one part where Phoenix says he has not seen him since [[spoiler: Miles' trial]] and just consider that they were really referring to Case 5 of the first game rather than Case 4 (Case 5 actually does somewhat set up Miles' disappearance). This problem was basically made due to bad porting. If they changed the background in Phoenix's little "Haven't seen him since" monologue, this whole problem would have never existed.
** What's really weird is, because of the order the games were released in overseas, the translations had every chance to fix this and write it so that no one would notice the problem, and they... didn't.
** This is fixed in the 3DS ''Trilogy'' rerelease. [[spoiler:When Edgeworth is brought up in the third case of ''Justice for All'', Edgeworth is stated to have stepped into a courtroom once after his own trial, that time being the fifth case]]. All references to [[spoiler:Case Four being the last time Phoenix saw Edgeworth]] are removed.
* The Franchise/{{Nasuverse}} has an interesting approach to continuity snarls.
** The first comes into place with Kagetsu Tohya, a sequel for ''VisualNovel/{{Tsukihime}}''. Kagetsu Tohya takes place in a dream world where the continuity is heavily blended and mutually conflicting events all take place together. For example, whether or not Akiha goes to Shiki's school depends on what he is thinking that morning. However, it should be impossible for this to be possible at all because the story is based around Len, and there is no route in ''Tsukihime'' where Shiki meets Len (Arcueid's familiar at the time) while Akiha goes to school with him. The continuity snarl occasionally confuses Shiki as well, but he's prevented from really thinking about it by Len.
** An equally weird example makes up the plot of ''VisualNovel/FateHollowAtaraxia'', which blends the timeline for ''VisualNovel/FateStayNight''. The nature of ''FSN'' means that almost the entire cast ''has'' to be killed off before the end, but they're all okay again in FHA. Characters who died in all three routes are back. [[spoiler:The reason for this is because Tohsaka accidentally merged a large number of continuities together, both ones we saw and ones we did not. Thus while Lancer was always killed, there was a continuity somewhere where he didn't. On the flip-side, Kotomine remains dead since he was fated to die in every possible continuity. Like the above example, dream worlds come into it somehow, but since it hasn't been fully translated it's not quite clear how it works out exactly.]]
** Finally, Ryougi Shiki appears in ''VideoGame/MeltyBlood'' despite word of god stating that she and Tohno Shiki do not share a universe because the odds of two people having the Mystis Eyes of Death Perception at any given time make it impossible. Nobody seems to have had the eyes for several thousand years, meaning the odds of having them manifest are at probably trillions to one. ''VideoGame/MeltyBlood'' has other issues than this, however. Satsuki is alive and a vampire, Arcueid is still around but not all yandere-y, Kohaku's route appears to have been partially resolved, Vermillion Akiha etc.
*** At least in Ryougi's case, she is explicitly stated to come from a different universe, as ''LightNovel/KaraNoKyoukai'' is set in an alternate reality from ''VisualNovel/{{Tsukihime}}'' and ''VisualNovel/FateStayNight''.

[[folder:Web Comics]]
* ''Webcomic/{{Drowtales}}''' rolling {{Retcon}} (repeatedly sequentially updating older chapters with new art and story) causes chaos for many fans' understanding of the comic's backstory, and there are ongoing debates on the forums as to what formerly canon information is current canon and what isn't.
* ''Webcomic/TheOrderOfTheStick'' parodies this trope with an actual entity called [[TropeNamers The Snarl]]; created when multiple Gods tried to create the universe and had disagreements about how things worked. The current FantasyKitchenSink of the setting was their way of avoiding this happening again.

[[folder:Web Original]]
* Literature/WhateleyUniverse: Does the magic department offer introductory classes for people with no previous magical ability? In one story, a magically inclined member of the school board (who, presumably, would know) explicitly says no. And yet, Ayla will be studying magic for the first time in the spring.
** A partial answer now exists: You need to be able to gather the energies of Magic in some way to take the courses in Magic (and it's explicitly noted that there are (inefficient) ways a normal human can do so).
*** But that still doesn't really work - in ''There's an Angel in Dickenson Cottage'' Lodgerman explicitly tells Kerry that her brother can't come to Whateley despite his enormous magical potential because Whateley only trains students who can already use magic. Ayla can't do this, but is somehow getting enrolled in a Magic 101 course anyway. Lodgerman may be lying for some reason or another, of course, but it isn't addressed.
*** It has since been explained that Circe (yes, ''that'' Circe) breaks many of the rules on the grounds that she also has a precognitive ability, meaning that those she trains really, ''really'' need her training due to some unspecified future event. Those to whom she offers her assistance tend to die horrible deaths -- or worse.
* ''WebAnimation/HomestarRunner'' is full of this. Strong Bad meets characters from [[ShowWithinAShow Shows Within The Show]] whom HE HIMSELF MADE UP.
* Any attempt to create a consistent origin for [[WebVideo/TheSpoonyExperiment Dr. Insano]] creates an awful one of these, mostly because there is no effort made to keep things in the [[NegativeContinuity slightest consistent]]. The Website/ThatGuyWithTheGlasses site now features an [[http://thatguywiththeglasses.com/videolinks/teamt/cr/ff/27514-dr-insano attempt to explain his existence]], which will probably be made inaccurate next time he shows up (the basic idea is that there are ''at least'' 3 of him around).
** Amusingly, Spoony's explanation for him is "There is no continuity, there is only Insano." Though he did say he was flattered that people cared enough to put forth the effort.
*** Later "explained" in ''WebVideo/ToBoldlyFlee'' as [[spoiler:the effect of [[NegativeSpaceWedgie the Plot Hole]], along with any and all other plot holes in the site's continuity]].

[[folder:Western Animation]]
* For all that's said about the inconsistencies between the Unicron Trilogy of the ''Franchise/{{Transformers}}'' franchise (''[[Anime/TransformersArmada Armada]], [[Anime/TransformersEnergon Energon]]'' and ''[[Anime/TransformersCybertron Cybertron]]''), the ''Franchise/TransformersGeneration1'' [[http://tfwiki.net/w2/images2/1/1d/Continuities.png timeline]] is even worse. It starts out with two distinct main branches, [[Comicbook/TheTransformers the original comic]] and [[WesternAnimation/TheTransformers the animated series]], but then along comes ''WesternAnimation/BeastWars'' and ''WesternAnimation/BeastMachines'' that uses elements from both series simultaneously. Add that to the splintering off done by the ''Dreamwave'' ongoing series, and you just have to wonder how all of these things could possibly co-exist together.
** The aforementioned series? In Japan, ''Cybertron'' is called ''Galaxy Force'', and it appears it's unrelated to its Japanese predecessors, ''Micron Legend'' and ''Superlink.'' The US version tries to tie the three together, but there are still some problems, so a comic was produced that chalked all of this up to a big warp in time and space... even though some minor retcons and a few lines of explanation saying where the older characters might have gone to would have sufficed. Yeah, it wouldn't have been perfect, but come on, was it really necessary... especially since they've already let the original timeline rage out of control? Also, most people are fine with that comic not being canonized, because the warp in space is caused by the black hole in ''Cybertron,'' which formed when the Super Energon sun created to sustain all the restored planets at the end of ''Energon'' collapsed. Basically, it would have made ''Energon'' the worst ShootTheShaggyDog DownerEnding in the history of fiction... and opened ''new'' holes with the continued existence of Cybertron and Jungle Planet.
** What makes it worse is that it suffers from Xorneto syndrome (see the ''X-Men'' example) in that the right hand seems to not know what the left hand is doing. ''All'' of the Unicron Trilogy's continuity problems could be solved with the "black hole's effect on the multiverse makes Cybertron the ComicBook/PostCrisis version of TheVerse" statement (that comes from the aforementioned comic. Just stop before you get to the part that makes ''Evangelion'' look like HappilyEverAfter by comparison.) That didn't stop ''everyone'' with the ability to create official material from explaining their own pet peeve a different way, explaining some things that didn't need explaining, and making the bigger problems all the more glaring.
** Worse, the show itself mentions none of this, and we're left with plot holes big enough for Unicron to fly through, even a few that would have been changed by a few lines. Starscream's back, not brainwashed into being ultra-loyal and not remembering anything, but also not a NobleDemon, instead more, well, TheStarscream. Jetfire is now Australian. Wing Saber is now a hothead. Sideways is back and has a different origin and final plan and nobody remembers him. Mini-cons have a different origin (including Jolt, who was major in Armada, as Hot Shot's Mini-con partner.) The biggest example is this: when Optimus and Leobreaker first combine, everyone is in total and absolute shock at the impossible - robots combining - happening. ''Guess what the main gimmick of both ''Armada'' and ''Energon'' was?'' (Hint: In Japan, ''Energon'' was called ''Super '''Link.''''') All it would take is a "Hey, Hot Shot, it's been a while!" from Jolt and similar acknowledgements of changes, or ''not'' going on about how combining, which used to happen all the time, is a shocking thing that has never happened before, or ''not'' giving Jetfire a new voice actor and style out of the blue to either completely cure the problem or at least make it fit together much better.
*** Oh, it gets worse: Takara has now decided that ''Galaxy Force'' ''is'' in continuity with ''Micron Legend'' and ''Superlink'', just as ''Cybertron'' is in continuity with ''Armada'' and ''Energon''. It should be noted, however, that many characters in ''Galaxy Force'' do not share names with anyone in ''Micron Legend'' and ''Super Link, ''whereas ''Cybertron,'' in a manner similar to ''Robots in Disguise'', named many characters after familiar ones. This makes the Japanese Continuity Snarl and the American one ''different'' - sharing TheVerse doesn't make single characters out of the ''Micron Legend / Super Link'' characters and whoever in ''Galaxy Force'' they most resemble. (This puts some FridgeLogic in the Japanese version, now full of {{Expy}} characters that coexist. In America, there's one medic named Red Alert. In the old Japanese continuity, ''Micron Legend'''s Ratchet and ''Galaxy Force's'' First Aid don't get in each other's way continuity-wise. In the new version, two guys happen to have highly similar head designs and replacements for their missing left hands by ''dumb luck'' and no one comments on it. Numerous similar examples exist.)
** The [[http://tfwiki.net/wiki/Image:Japaneseflowchart.jpg Japanese G1 timeline]] also considers [[Film/{{Transformers}} the live-action film series]] and seemingly unconnected series ''Anime/TransformersRobotsInDisguise'' as part of the original continuity. Try to make sense of THAT.
*** Oh, yeah, and ''WesternAnimation/TransformersAnimated''? That one that took place in the 22nd century, made the Autobots virtual celebrities on Earth, had a completely different style and design aesthetic, included superheroes, genetic experiments GoneHorriblyWrong, and robots being so commonplace that they were used to teach, and [[spoiler:ended with Megatron in chains and Starscream a dead traitor]]? In Japanese continuity, [[LogicBomb it's a prequel to the live-action film.]] [[LyingCreator Except that it isn't.]]
** Furthermore, some characters are "multiversal singularities", meaning that every incarnation of a certain character (like, say, The Fallen) is the same being, instead of just some alternate version. This leads to some headache inducing retcons among other things, and may have been part of the reason why Fun Publications did away with the concept in 2015.
** Sideways's whole ''existence'' is one of these. How bad is it? At [=TFWiki=], many characters have a Disambiguation page (after all, think of how many unrelated incarnations of TF have an Optimus Prime?) Sideways is the only character whose disambig page has a "Fiction" section.
** Out-of-universe, first we have the RID 2001 toy, then the ''Armada'' toy which uses the same bio, reworded to add Minicons. Then the Armada character, an agent and ''offshoot'' of Unicron. Then the ''Cybertron'' character: same name, same gimmick, different revelation about who he is. These are considered to be the same guy, officially. Then the explanation of Cybertron's differences from the connected Armada series -- Unicron exists in all dimensions and as such, all are affected by the black hole -- better known as the ''Unicron Singularity.'' As "multiversal singularities," Primus, Unicron, and their direct creations exist in all dimensions as the same person. This would mean that Sideways can exist in multiple universes and seem to have a complete, differing history in each, but it's always still him and he'll always be Unicron's herald. The ''Animated'' ExpandedUniverse makes Animated Sideways and Movie Sideways maybe the same guy, and colors him like Armada Sideways… ''without'' anything beyond colors to say that he's also that one. Movie Sideways is cut in half and reappears in the next movie (the likes of which is no big feat for Armada Sideways, who can take many forms and whose true form seems to be energy that looks like multicolored television static), and his toy bios treat him as a manipulator like Armada and Cybertron Sideways, suggesting that he is Armada Sideways or at least just like him… but toy bios say a ''lot'' about movie characters that clashes with the movies, and a lot of movie Decepticons have the same or similar body types. Canon as it was understood at the time of the Unicron Trilogy would seem to make Armada Sideways the true identity of all the others, but there just kept not being any sign of that in later appearances - or any acknowledgement of different series existing in TheMultiverse in any television, film, or mainstream comic incarnation. Finally, they embraced the fact that sense cannot be made of it: the "Ask Vector Prime" column, where fans can ask things of the ancient TimeMaster and get in-character tongue-in-cheek answers, has Sideways take over for one installment when the question is asked - ''first'' he reminds us that [[UnreliableNarrator he's a lying liar who lies]], and tells us that all, some, or none of the past ideas of who he is are totally true… or not.
-->Sideways: "Everything you think you know about me was [[ConsummateLiar a lie told by me to confuse someone]], or [[WordOfGod conjecture from someone]] [[GodDoesNotOwnThisWorld who'd be in no position to know]]. So yeah, maybe I'm a [[Anime/TransformersArmada fragment of Unicron]], because maybe [[Anime/TransformersCybertron Planet X]] [[ExpandedUniverse used to]] [[ArcWelding BE Unicron]]. And maybe I'm [[Anime/TransformersArmada his avatar made manifest]] and untethered once he [[Anime/TransformersCybertron collapsed into a giant singularity]]. And maybe I'm from the Cybertronian Empire.[[note]]"Ask Vector Prime" gives a connection between Planet X and the Cybertronian Empire. Assuming you take Ask Vector Prime as canon at all.[[/note]] [[TheMerch And maybe]] [[FlavorText I'm just]] an [[Anime/TransformersRobotsInDisguise ordinary Autobot who went crazy]] from [[Anime/TransformersArmada Powerlinxing to the wrong Mini-Cons]]. Maybe I'm [[MultipleChoicePast all of those things, or none.]] And you know what the best part is? [[RiddleForTheAges You'll. Never. Know.]]
** Indeed, the entire "multiversal singularities" concept turned into this pretty quick. For instance, the Unicron of the cartoon rather clearly ''isn't'' a multiversal god; he had a canon origin as having been [[AIIsACrapshoot created by a scientist.]] The Fallen, who was always intended to be one rather than retconned into one, ran into this when a version of him appeared in the live-action films as [[AdaptationalWimp a completely incompatible figure.]] Vector Prime straight-up dies in ''Anime/TransformersCybertron'', yet nobody acknowledges this. WordOfGod on ''WesternAnimation/TransformersAnimated'' is that Primus doesn't exist there, throwing into question how ''Animated'' fits into it. And then when Aligned kicked off, it created a list of the Thirteen that excluded Logos Prime (who is very obviously intended to be one) and added Alpha Trion (who has a long history in multiple continuities that's utterly incompatible with him being in the Thirteen, including a MirrorUniverse doppelganger and having clearly aged), prompting the explanation that the Aligned continuity is somehow separate from the others. Rather than making the Thirteen seem cooler, [[VoodooShark the whole thing ended up just raising hundreds of questions]], so much so that the concept was erased by CosmicRetcon.
*** The Fallen's application ran into a particular case of this. In the ''Transformers'' multiverse, contradictory stories are explained as the result of the audience looking at a parallel universe - for instance, a toy bio where a character who is dead is treated as alive means that there's a universe where they survived or came back. This is also the case for multiple adaptations of the same story -- the novelization of an episode's plot takes place in its own universe to the episode. Now combine that with the above information about The Fallen and the massive amount of ancillary material surrounding ''Film/RevengeOfTheFallen'', and you have the [[FridgeLogic apparent situation]] where the Fallen dies at the end of the movie, somehow survives, travels to the universe of the novelization, lives out his entire long history in the exact same manner and enacts the exact same scheme, dies in the exact same way, travels to the universe of the comic book adaptation, to the read-along storybook, to the video game, to the portable version of the video game, and so on and so forth, failing miserably every single time.
** The latest incarnation of the Transformers mythos is still neonatal (a couple of months old as of this writing), and it's ''already'' turning into a Continuity Snarl. According to the powers that be, the video game ''VideoGame/TransformersWarForCybertron'', the novel ''[[Literature/TransformersExodus Exodus]]'', and the TV series ''WesternAnimation/TransformersPrime'' are all part of the same continuity. The problem is, the plots for ''Exodus'' and ''War for Cybertron'' are so disparate and contradictory as to be completely incompatible. Time will tell whether the ''Prime'' cartoon will make any attempt to address these discrepancies, or whether it will [[ShrugOfGod quietly sweep them under the rug and ignore them]], and [[MST3kMantra encourage the fans to do the same]]. ''War''[='=]s sequel ''VideoGame/TransformersFallOfCybertron'' makes some attempts, though ''Prime''[='=]s sequel, the current ''[[WesternAnimation/TransformersRobotsInDisguise Robots in Disguise]]'' makes things worse as Bumblebee, Sideswipe, and Grimlock don't seem to recognize each other. [[WordOfGod Producer Adam Beechen]] [[https://twitter.com/sonnova/status/606586570980749312%7C later said]] that Grimlock is a common name among Dinobots and that ''[=RiD=]''!Grimlock isn't ''[=FoC=]''!Grimlock, but a different character. Website/TFWikiDotNet takes this a step further and presents the Sideswipes as separate characters as well.
*** [[WordOfGod Later statements by Hasbro]] have clarified that ''War For Cybertron'', ''Exodus'', and ''Prime'' are part of the same continuity in the same way that the original Transformers cartoon and the Marvel, Dreamwave, and IDW comics are all part of the G1 continuity -- that is, they share similarities in aesthetics and characterization, but are not necessarily consistent with one another. The fandom generally uses the term "continuity '''family'''" to refer to such an arrangement, and this difference in terminology is part of the reason some fans continue to grumble about discrepancies in canon between the three works.
*** Even that doesn't satisfy all, just because ''War for Cybertron'' was ''so'' G1 Prequel-y (its cast is G1 characters and ''only'' G1 characters and their pre-Earth designs were largely based on ''The War Within,'' Dreamwave's G1 prequel.) and had nothing in common with ''Prime.'' However, they're working at fixing the problem via some ArcWelding: ''Prime'' writers ''are'' making references to it, and the second game in the series, ''Fall of Cybertron,'' is also looking more at ''Prime'' than at G1 when it comes to what events it's setting the stage for (though it's still using all G1 characters. Welcome back, Bruticus!) Also, ''Prime'' Shockwave looks very much like ''Fall of Cybertron'' Shockwave.
*** The Aligned continuity gained a new one when both ''The Art of Prime'' and ''The Covenant of Primus'' decided to address the dead Prime whose arm Megatron stole for his BadassTransplant in [[Recap/TransformersPrimeS2E21AlphaOmega "Alpha; Omega"]]. According to notes for Megatron's design in ''Art of Prime'', he stole it from Sentinel Zeta Prime, but according to ''The Covenant of Primus'', it came from the Liege Maximo, one of the original Thirteen. For what it's worth, Wiki/TFWikiDotNet has decided to go with the ''The Covenant of Primus'' explanation.
*** Speaking of "Sentinel Zeta Prime," ''he'' is an attempt to clean up a minor one. One source says the Prime before Optimus is Sentinel Prime and one says it's Zeta Prime, so Hasbro decided, "why not make them the same guy?"
*** ''VideoGame/TransformersRiseOfTheDarkSpark'' is a plot that involves both the ''Film/TransformersFilmSeries'' and the ''Aligned'' universe, with the Aligned part being an {{interquel}} between ''War for Cybertron'' and ''Fall of Cybertron'' and the film section taking place roughly around ''Film/TransformersAgeOfExtinction''. Among the problems is that Aligned!Megatron is shown in his rebuilt form from ''[=FoC=]''--despite only getting it that that story, Lockdown having different motivations (being greedy and missing the war in the game, hired by [[spoiler:Quintessa to capture Optimus]] in the movie), Stinger being with Lockdown already, the Dinobots already being with the Autobots, and Movie!Optimus and movie!Bumblebee already in the forms they gain in the movie.
** And then there's [[http://tfwiki.net/wiki/Prowl_II Prowl II]], who is what happens when the ''Beast Wars'' snarl and the ''Binaltech'' snarl make sweet, sweet love while neither side knows what the other is doing. The short version is that he was intended to simply be a future version of G1 Prowl, and by the end, he was an amnesiac future clone of another universe's G1 Prowl with the soul of his universe's Chip Chase, occupying a body that originally held the soul of the Chip from the other universe, while the actual G1 Prowl is dead and the one from another universe is now a lion on the OmniscientCouncilOfVagueness. And this is considered the "fixed" version.
* Played for laughs on ''WesternAnimation/AmericanDad'' when Roger explains the background of a character he's made up for himself:
-->'''Roger:''' My name is Braff Zacklin. I was an international race car driver. One day, a baby carriage rolled out onto the track so I swerved into the retaining wall to avoid it. The car burst into flames, but the baby miraculously survived ... I was that baby.
-->'''Steve:''' That doesn't make any sense.
-->'''Roger:''' I'm Braff Zacklin!
* ''WesternAnimation/StarWarsTheCloneWars'' begins to run into this during the third season. All of the episodes take place in AnachronicOrder, making their placement already difficult. Some even {{retcon}} the timeline for past episodes. For example, events in one episode took place in between the two prior season finales... and implied the second season finale took place before the first.
** It doesn't help that the series itself is retconning a fair amount of older series, such as many of the ''Literature/{{Republic Commando|Series}}'' novels.
*** Thankfully, the ''Republic Commando'' novels [[AllThereInTheManual have been safely salvaged]].
** Not to mention killing off a Jedi Master in the middle of the Clone Wars who explicitly was still alive ''after'' the war ended.
** It doesn't help that Creator/GeorgeLucas has called the ''Franchise/StarWarsExpandedUniverse'' a parallel universe, so doesn't feel particularly beholden to upholding it.
** The continuity between episodes has been fixed. The show airs in syndication in a new and chronological order that starts a few weeks after the second life-action film in which Anakin got his scars and became a knight.
* ''WesternAnimation/CareBearsMovieIIANewGeneration'' does this to previous works in the ''Franchise/CareBears'' franchise, from having the Care Bear Cousins grow up with the rest of the Care Bears, instead of separately in ''WesternAnimation/TheCareBearsMovie''.
* Parodied in ''WesternAnimation/TheFairlyOddParents'' where it shows all of the different versions of Crimson Chins there are from the different decades of comic books. They all have different appearances, attitudes and one was even banned (the "super edgy [[UsefulNotes/TheDarkAgeOfComicBooks 1985]]" one who [[SirSwearsALot swore excessively]]).
** Played straight in the series with its own continuity. The inclusion of Poof as a main cast member has brought up some confusion regarding his absence in the finale of the movie ''WesternAnimation/ChannelChasers''. Also, the addition of Sparky in Season Nine brings on more continuity issues, such as Sparky not being there on the end of ''WesternAnimation/ChannelChasers'' (the same contradiction happened with Poof) and he not being on the live-action movies - ''[[Film/AFairlyOddMovieGrowUpTimmyTurner A Fairly Odd Movie]]'' and ''Film/AFairlyOddChristmas'' - both taking place thirteen years after the events of the main series. In ''Film/{{A Fairly Odd Movie|GrowUpTimmyTurner}}'', there is even a scene in which Wanda states that Timmy doesn't have a dog.
** The biggest one occurs near the end of ''Film/AFairlyOddSummer'', in which [[spoiler:Timmy's HeroicSacrifice has caused him to [[AscendToAHigherPlaneOfExistence turn into a fairy]]]].
* Creator/JephLoeb has stated in several interviews that ''WesternAnimation/UltimateSpiderMan'' and ''WesternAnimation/AvengersAssemble'' share the same universe as ''WesternAnimation/TheAvengersEarthsMightiestHeroes''. As you can tell by the first episodes of both ''Ultimate'' and ''Assemble'', this would only work in heavy BroadStrokes. The most noticeable contradiction being the apparent age difference between [[ComicBook/ImmortalIronFist Iron Fist]] and ComicBook/{{Luke Cage|HeroForHire}} as seen in ''Ultimate Spider-Man'' and ''The Avengers: Earth's Mightiest Heroes!'' and Comicbook/TheFalcon being a rookie in ''Assemble'' whereas he was already active in ''EMH''.
** Related to ''EMH'', Chris Yost, Craig Kyle, and Josh Fine have said it, ''WesternAnimation/WolverineAndTheXMen'', and the "Wolverine" short of ''WesternAnimation/HulkVs'' are all set in the same universe--despite the number of things that contradict each other, like Bruce Banner not remembering Wolverine in ''[=WatXM=]'', despite Wolverine's behavior to Banner being the direct cause of both of Banner's main Hulk-outs in the "Wolverine" short.
* Various Cartoon Network shows have been implied to be in the same Universe, perhaps most notably in WesternAnimation/{{The Grim Adventures Of|BillyAndMandy}} [[WesternAnimation/CodenameKidsNextDoor The Kids Next Door]], but this simply can't be. All of these shows have had their own versions of SantaClaus appear who looks different from the other show. In addition, episodes of shows like ''WesternAnimation/DextersLaboratory'' show NegativeContinuity like the entire ''Earth'' being destroyed or an episode of ''WesternAnimation/TheGrimAdventuresOfBillyAndMandy'' where Mandy wishes everyone in the world to go away, which can't exist in the same place as shows like ''WesternAnimation/CodenameKidsNextDoor'' which clearly have continuity.
* ''WesternAnimation/TheLittleMermaid'' prequel TV series has a couple. In [[Disney/TheLittleMermaid the movie]] Sebastian barely knows Ariel and is assigned to watch over her after she misses the concert. In the TV series he's part of her TrueCompanions and they act as if they've known each other for years. Additionally Sebastian doesn't discover Ariel's grotto until the "Part of Your World" number - after he's only just been told to keep an eye on her. The TV series has him appearing in the grotto numerous times. Otherwise subverted with other details. Eric appears on the show a couple of times but Ariel never sees him, preserving the continuity of their first meeting in the movie. Likewise Ursula appears but is not defeated and does not interact too much with Ariel. ''Disney/TheLittleMermaidIII'' showed Flounder and Ariel meeting for the first time and portrayed Flounder as extroverted and daring. The TV series showed them meeting as children and Flounder is portrayed as timid (but brave when necessary) and cautious in every other media.
* Likewise, ''WesternAnimation/{{Hercules}}'' is rather hard to gel with [[Disney/{{Hercules}} the movie that it's based on]]. It's about Hercules attending school while trying to be a hero...so, like, set during the film's TrainingMontage, but before his "first" heroic deed against the Hydra. (Given how dismissive people are of him in the film, they've apparently forgotten his TV-show feats.) Also, in the movie it's a plot point that [[EverybodyHatesHades Hades]] thinks that Hercules is dead, but here they interact pretty much OncePerEpisode, which also makes it odd that he has to introduce himself to Hercules during the film's Titan invasion. It's best to just to throw up your hands and call it BroadStrokes.
* Due to the sheer length of time it's been on the air coupled with its ageless cast and focus on American cultural commentary, ''TheSimpsons'' has increasingly severe continuity problems regarding when the characters were born, what generation they belong to, etc. Early episodes, set in the early 1990s, established Marge and Homer as kids of the late 1950s — baby boomers, basically — with Bart and Lisa being kids of the early 1980s. Early episodes flashbacks were completely unambiguous about this — young Homer watching JFK on TV, Lisa's birth overlapping with the 1984 Olympics, and so on. However, the show has survived for so long, it is now impossible to honor this past without absurdity — Lisa cannot still be eight years old in the late 2010s if she was born in the 1980s, etc. Flashbacks in contemporary episodes now have to occur in some vague, unspecified "past" with decade-identifying details scrubbed, though this is not so easily done for certain characters for whom time-sensitive events are a big part of their identity: for example, Abe being a WWII vet, Seymour having served in Vietnam, Marge, Homer, and Artie Ziff having attended a very 60s prom — to say nothing of Disco Stu! It seems many of these details are being quietly retired for snarl reasons.
* The ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' chronology makes absolutely no sense simply going by the show, with multiple episodes set during a specific time of year appearing across three seasons... at which point it was revealed that a year had passed. Show staff have admitted that firm canon has never really been that important to them, though effort is made to keep everything relatively coherent such that one can HandWave it as AnachronicOrder. The books, show, comics and supplementary material also all have their own issues with each other if taken as one overall canon.
** The official WordOfGod line is that any supplementary material can be considered canon, unless the show contradicts it, in which case the show's canon wipes it out. But this still runs into trouble with the comics' "Siege of the Crystal Empire" arc, a massive battle with numerous villains over the show's history...at least the few that the poor writer tasked with putting it together was actually able to use given the show's love of reforming its villains. He even resorted to using Iron Will, a character previously presented as a bit rough around the edges but in no way a villain even in another comic issue.
* The Franchise/DCAnimatedUniverse has a couple because of ''WesternAnimation/JusticeLeague'':
** In the ''WesternAnimation/SupermanTheAnimatedSeries'' episode, "Blasts from the Past, Part 1", Lois Lane makes a snarky remark, saying, "Yeah, and I'm Wonder Woman," which suggests that Wonder Woman was already active in the DCAU. In ''JL'', Diana is presented as a rookie and a newbie to Man's World.
** Likewise, the ''S: TAS'' episode "Apokolips... Now, Part 2" features Forager among the New Gods from New Genesis, yet in "Twilght" he's not yet among their numbers until the end of the episode.
* The ''WesternAnimation/CloudyWithAChanceOfMeatballs'' TV spin-off is branded as a prequel to the two movies with Flint Lockwood in high school. If it is truly a prequel, however, then there are some inconsistencies with the movie's canon. Most noticeably, Sam Sparks is attending the Swallow Falls high school ''with'' Flint despite it never being established in the either of the two movies that Sam had ever been to Swallow Falls before being sent there in the beginning of the first movie. Additionally, Manny (Sam's camera man) is also a Swallow Falls resident (who doesn't add up for the same reason as Sam), and Mayor Shelbourne has an actual son (instead of a metaphorical son) [[CanonImmigrant who never appeared in either of the movies]] that are set after this series.
* Due to CanonWelding with the comics it was based on, ''WesternAnimation/DuckTales1987'' (and its spin-off ''WesternAnimation/DarkwingDuck'') is covered on the ContinuitySnarl/ComicBooks page.

[[folder:Real Life]]
* Trying to keep track of everything that happened after the death of [[UsefulNotes/AlexanderTheGreat Alexander of Macedon (aka the Great)]] is almost impossible for anyone, even those with higher degrees in Classical History. The scale of the political maneuvering between his putative successors is too large to summarize. Suffice to say that one Classical Historian has described the carnage and politics between Macedon, Persia, the Ptolomaic Empire, and all the others, as a 'Macedonian Soap Opera'.
* A similar case can be made in tracing the outcome of the Mongol Horde. It doesn't help that the Mongols didn't have a sophisticated writing system until they began to be assimilated to the culture of the invaded peoples. It doesn't help even further that the Khans valued secrecy if not deliberate obfuscation-- where is the Tomb of Genghis Khan? Who was split from who? And the few Europeans who wrote about them had no idea of many aspects of their culture and their own religious and ethnic prejudices to contend with (to say nothing of wishing to please rulers or wealthy people who paid them).
* The UsefulNotes/WarsOfTheRoses are sure to induce headaches in just about anyone studying them for the first time. The family trees are incredibly complicated (which is part of what started the whole mess, really), and the fact that the entire nobility seems to have been determined to choose from the same list of ten or so first names can make one dizzy after a while. For instance, Humphrey Stafford, 1st Duke of Buckingham, had several sons, the first two of which were Humphrey and Henry. ''Both sons married women named Margaret Beaufort''. (The sons' mother, by the way, was Anne Neville... '''but not''' the Anne Neville that married UsefulNotes/RichardIII. Totally different Anne Neville.)
* Likewise, if you're interested in Literature/{{Dracula}} enough to study UsefulNotes/VladTheImpaler, prepare to pick your jaw up off the floor when you see the preposterously chaotic history of the [[http://en.wikipedia.org/wiki/List_of_rulers_of_Wallachia Wallachian throne.]] Rulership of the principality sometimes changed hands multiple times in a single year, and some rulers had five or even six separate reigns to their name.
* Similarly, UsefulNotes/TheMexicanRevolution. Once the United States got involved, it gets even more confusing because the [[UsefulNotes/WilliamHowardTaft Taft]] and [[UsefulNotes/WoodrowWilson Wilson]] administrations supported opposite sides of the conflict. And this is leaving out historiological debates over the whole mess.
* [[http://en.wikipedia.org/wiki/Schleswig-Holstein_Question The Schleswig-Holstein Question.]] [[UsefulNotes/TheViscountPalmerston Lord Palmerston]] is said to have remarked of it, "Only three people have ever really understood the Schleswig-Holstein business — the Prince Consort, who is dead, a German professor, who has gone mad, and I, who have forgotten all about it."
** As a result of a GambitPileup that's been going on for centuries.
* Any time a city has [[NamesTheSame two teams with the same name]] at different times, it can lead to this. A good example in the UsefulNotes/NationalHockeyLeague: from 1971 to 1996 there was a team called Winnipeg Jets, which has since moved to Arizona as the Phoenix Coyotes (later on being the Arizona Coyotes in 2014). In 2012, the Atlanta Thrashers moved to Canada, where they were rechristened... Winnipeg Jets!
** Similarly, the [[UsefulNotes/NationalBasketballAssociation NBA's]] Charlotte Hornets moved to New Orleans in 2002, and in 2013 the new owner decided to rechristen them New Orleans Pelicans to lose the ArtifactTitle (the name came from how in the American Revolution Charlotte was described as "a hornet's nest of rebellion") and get something that fit Louisiana. Then UsefulNotes/MichaelJordan, owner of the Charlotte Bobcats (which started play in 2004), said his team would get the Hornets name back in 2014. Though once the Charlotte Hornets were revived with the rename, they made sure to say that the NBA allowed the "new" team to share the pre-New Orleans history, like...
** The Cleveland Browns in [[UsefulNotes/NationalFootballLeague the NFL]]. The original team wanted to move to Baltimore, but the city of Cleveland won a lawsuit against the National Football League, in which while the team's roster and staff would move to Baltimore to become an "expansion team" known as the Baltimore Ravens, a new team would begin operating under the old Browns banner three years later. While the new Browns team was originally stocked with personnel in the way that expansion teams usually are, the NFL considers the Browns to be one continuous franchise that "suspended" operations for three years, retaining all the awards the team had won prior to the move.
** Then there's the UsefulNotes/CanadianFootballLeague which had, for a number of years, one team called the Roughriders (one word) and another called the Rough Riders (two words). (This is because the CFL was formed by the merger of two smaller leagues, each of which had a team with that name at the time.) The Ottawa Rough Riders have long since shut down as a team, but the name could be reactivated if someone wanted to buy the right to it from the current owner. (A new Ottawa CFL team began play in 2014, but it's known as the Redblacks and has no particular connection to the former Rough Riders except being based in the same city.) The Saskatchewan Roughriders remain in the CFL.
** When UsefulNotes/MajorLeagueSoccer team the San Jose Earthquakes moved to Houston after the 2005 season, the league's commissioner stated that the Earthquakes' history, records, name, and colors would remain in San Jose, waiting for a new expansion team. The Earthquakes returned in 2008, taking the old team's history.
** In Romanian [[UsefulNotes/AssociationFootball football\soccer]], CS Universitatea Craiova tries to reclaim the story of [[https://en.wikipedia.org/wiki/FC_Universitatea_Craiova another Universitatea Craiova]] that's currently in limbo due to financial problems, but the national association refuses to acknowledge that.
** How about a time where one city had two teams with the same name, at the same time? The Chicago Cardinals (now the Arizona Cardinals) started their career in 1920, but moved to St. Louis in 1960. At the same time, St. Louis already had a St. Louis Cardinals team: [[UsefulNotes/MajorLeagueBaseball the MLB team]]. The Cardinals football teams moved to Arizona in 1988, going off to California, being replaced in the '90's by the Rams, from Los Angeles. The St. Louis Rams left in 2015, going back to LA, and becoming the LA Rams again.
* In American college sports, there have been several examples of this phenomenon:
** In 1907, the Missouri Valley Intercollegiate Athletic Association was formed. In 1928, the conference split mostly along public/private school lines; both factions claimed the MVIAA name for a time. One faction eventually became known as the Big Six Conference, later the Big Seven and Big Eight. The other became the Missouri Valley Conference. The Big Eight merged with four schools from the disbanding Southwest Conference in 1996 to form today's Big 12 Conference, while the MVC operates to this day.[[note]]The Big 12 does not claim the history of the Big Eight, which means that only the MVC now has a claim to the MVIAA's old history.[[/note]]
** There have been two separate leagues known as the Big East Conference. The original was founded in 1979 as a basketball-first league. In 1991, it added football, and entered into two decades of turmoil, mostly involving the split between schools that played top-level football and those that didn't. The conference finally split along football lines in 2013. The seven schools that did not play FBS (top-level) football bought the "Big East" name, and joined with three other schools to form a new Big East Conference under a new charter. The FBS football schools that were left behind, plus other new members, retained the charter of the original Big East, but are now known as the American Athletic Conference.
** Speaking of the Missouri Valley Conference, it has been involved with an even more confusing example of this trope, one that also involves the conference now known as The Summit League.
*** In 1977, six schools in the Midwest formed the Mid-Continent Athletic Association, a football-only league, with play starting in 1978.
*** Then, in 1982, the Association of Mid-Continent Universities (the conference now known as The Summit League) took over the MCAA.
*** The MVC got involved in this snarl in the same year when its member schools formed the Gateway Collegiate Athletic Conference, a separate though related league specifically for women's sports.
*** By this time, the MVC was operating a hybrid football league that contained teams both in Division I-A (today's FBS) and the second-tier Division I-AA (now known as FCS).
*** After the 1984 season, the MVC decided to drop football. Coming to the rescue... ''the Gateway''. Yes, the ''women's league''. It took on football as its only men's sport, absorbing both the MVC's I-AA programs and all of the Mid-Continent football teams.
*** In 1992, the MVC took over the Gateway, spinning the football conference off into a new entity which immediately renamed itself the Gateway Football Conference.
*** Finally, in 2008, the football league renamed itself the Missouri Valley Football Conference.
* The [[https://en.wikipedia.org/wiki/Crisis_of_the_Third_Century Crisis of the Third Century]] in Roman History is one to modern historians. Not only were there multiple civil wars and rival claimants for the throne (26 of them over a 50 year period), but the historical records we do have for the area contradict each other regarding when events happened. In some cases, it's unclear whether multiple battles took place at particular locations years apart, or whether there was only a single battle that's been recorded incorrectly.
* Generally speaking the line between "history" and "pre-history" is drawn where written records exist. However, the vast majority of all the stuff ever written (even all the stuff of historic significance ever written) does not survive to this day and literate and illiterate cultures have existed side by side for most of history. And the sources often had other things in mind than telling an accurate account of history as best they could. Many authors wanted to make one side or political faction look good or bad, delegitimize or legitimize current claims or past acts and of course people were occasionally declared UnPerson. Even for periods of the Roman Empire where multiple authors survive, historians tend to mistrust the sources to some degree as they almost all were of senatorial rank and had certain biases. An emperor who pissed off senators is certain to have gotten a HistoricalVillainUpgrade, whereas an inept or brutal ruler who pleased the senate may have gotten a HistoricalHeroUpgrade. And when several claimants vied for power, authors writing after the fact were liable to dismiss those that missed out on power or whose memory the current rulers didn't want to evoke, even if they actually got to rule for significant amounts of time.