History Main / AlternateTimeline

* ''Series/TheTwilightZone1985'': In "Profile in Silver", a time traveling historian from 2172 named Professor Joseph Fitzgerald [[SetRightWhatOnceWentWrong prevents]] the [[WhoShotJFK assassination]] of his FamousAncestor UsefulNotes/JohnFKennedy on November 22, 1963. The resulting change to the timeline leads to the creation of significant time distortions and a temporal rift of unprecedented proportions. Tornadoes appear without warning in Texas as part of the initial attempt to counterbalance the temporal damage. The assassination of UsefulNotes/NikitaKhrushchev results in the new Soviet premier sending in troops to capture West Berlin in an attempt to force the Western powers out of the rest of West Germany. Fitzgerald's wrist computer determines that there is a 77% probability that a [[WorldWarIII nuclear war]] will break out between the United States and the Soviet Union, resulting in the [[PollutedWasteland total annihilation of the biosphere]]. At 12%, the best case scenario is that Western Europe will surrender within six years. Military costs will cause the Soviet economy to collapse, leading the USSR to blackmail the West for food. The subsequent agro-bacterial war will completely destroy the biosphere within a century. The remaining 11% accounts for all other probabilities in which the biosphere is destroyed. From this, Fitzgerald learns that Kennedy's death is a NecessaryFail and that history must be restored to its proper course if humanity is to survive.

This trope does get a bit confusing on a meta level, when you take an installment and have {{Alternate Continuit|y}}ies in parallel. To explain, consider two works of speculative fiction: one optimistic and depicts a utopian future, the other is pessimistic and depicts a dystopian future. Obviously both can't happen at once, but until the future arrives they're both equally valid, and both take place in the same world -- our world. Basically, the main difference between an Alternate Timeline and an AlternateContinuity is that Alternate Timelines share {{backstory}} and were formed at a point of divergence, with the "new" timeline simply ''overwriting'' the "old timeline" [[ForWantOfANail as a result of said divergence]]. In other words: Alternate Continuities ''do not share the same {{canon}}'', whereas Alternate Timelines ''do''.

This is often caused by TimeTravel and ForWantOfANail.

* The ''VideoGame/MegaManClassic'' metaseries has one, expanded on in ''VideoGame/MegaManBattleNetwork''. Both Doctors Light and Wily presented their research to the government: network and robotics, respectively. In the world where Light's network research won out, the ''Battle Network'' and ''VideoGame/MegaManStarForce'' games take place. [[ForWantOfANail However, when Wily's robotics were chosen instead]], it led to the "Classic" series and its various SequelSeries in ''[[VideoGame/MegaManX X]]'', ''[[VideoGame/MegaManZero Zero]]'', and ''[[VideoGame/MegaManZX ZX]]'' (with ''[[VideoGame/MegaManLegends Legends]]'' occurring [[DistantSequel far off in the future]] of this timeline).

* The Music/{{Madness}} Musical; ''Theatre/OurHouse'', has the Lead Character breaking in to a development site, so he can get a view of his Neighbourhood, but then the Police arrive. It then shows two time lines, one where he turns himself in, another where he runs, showing the consequence of both choices, while his [[PosthumousNarration father's ghost]] watches and makes commentary on his choices. [[spoiler: Then at the end it [[SnapBack Snaps Back]] to the beginning and shows a third time line, where he doesn’t break in to the development site in the first place]].

* ''WebVideo/TheFinalMinutes'' gives us ''[[https://www.youtube.com/watch?v=asvaYp2u4SI Trumpocalypse]]'', an alternate timeline scenario which takes place in a BadFuture where then-president Donald Trump reacts [[{{Understatement}} badly]] to being declared insane and subsequently impeached, culminating in all-out ''nuclear war''.

* ''Franchise/StarTrek'' has had many episodes in all five series featuring alternate timelines. For more information, [[http://en.memory-alpha.org/wiki/Alternate_timeline click here]].

* ''VideoGame/GhostTrickPhantomDetective'' has an in-game instance: the first timeline is a BadFuture where [[spoiler:everybody dies, Missile is unable to save them due to lacking the needed ghost tricks, and Sissel refuses to help Missile due to only being concerned about his own quest for identity. At the end, Missile uses Yomiel's no-longer-immortal body to travel back in time 10 years to the Tesmik Park incident and [[TheSlowPath wait out those ten years until that night returns]]]]. Then starts the second timeline, [[spoiler:which is the Bad Future again, but diverging when Sissel awakens and Missile from the first timeline guides him under the guise of Ray, making Sissel think he's a blond-haired man in red instead and claiming that he'll cease to exist once morning comes, so that he'll naturally save Lynne and everyone else that could be a lead in his quest for identity due to said man's interactions with them]]. The third timeline begins [[spoiler:after Sissel, Missile from the second timeline, Yomiel, and Detective Jowd go back 10 years again like the original Missile did and SetRightWhatOnceWentWrong by saving Yomiel's life and thus preventing his StartOfDarkness]], undoing the first two timelines [[spoiler:and [[RetGone the first Missile's existence]]]] in the process.

** [[TimeyWimeyBall Here's where things get confusing]]. After Trunks returns to Timeline A and shuts down the Androids there, he's killed by a creature called Cell just before he uses the time machine to tell his friends the good news. Cell takes the time machine and arrives in the past, two years before Frieza and King Cold do, creating Timeline C (the one depicted in full via the manga and the anime). Cell won't emerge in earnest until soon after the Androids show up, and usurps them as the main threat to defeat by absorbing them and their power. While Trunks trains to try and defeat him, Cell would ultimately be killed by Gohan. Trunks also kills an embryonic Cell before he can become fully grown, which prevents another future from being ruined, and everyone who was killed by Cell (including the Androids) are revived by Shenron. This includes the Androids, who undergo a HeelFaceTurn.

** [[TimeyWimeyBall Here's where things get confusing]]. After Trunks returns to Timeline A and shuts down the Androids there, he's killed by a creature called Cell just before he uses the time machine to tell his friends the good news. Cell takes the time machine and arrives in the past, two years before Frieza and King Cold do, creating Timeline C (the one depicted in full via the manga and the anime). Cell won't emerge in earnest until soon after the Androids show up, and usurps them as the main threat to defeat by absorbing them and their power. While Trunks trains to try and defeat him, Cell would ultimately be killed by Gohan.[[note]]It's also worth noting that during this, Trunks kills an embryonic Cell before he can become fully grown, which prevents another future from being ruined.[[/note]]

* ''Franchise/TheLegendOfZelda'': The series was [[WordOfGod officially stated]] to take place in a split timeline caused by the use of TimeTravel in ''VideoGame/TheLegendOfZeldaOcarinaOfTime''. It was originally thought by fans that the game split it into two different timelines, until ''Literature/HyruleHistoria'' revealed that there are ''three'' timelines:

** For a long time there was no official word on which of these timelines ''[[VideoGame/TheLegendOfZeldaBreathOfTheWild Breath of the Wild]]'' takes place in, with clues for each one. Some say that it's the result of all three timelines somehow merging back into one. Others say that it takes place so far in the future that [[InSpiteOfANail it no longer matters which timeline it is]]. It turned out to be a case of both in [[https://www.nintendo.co.jp/character/zelda/history/index.html the latest version of the chronology.]]

%%* ''Franchise/CodeGeass'' has an alternate version of our history, wherein the American Revolution was defeated by the British Empire following Benjamin Franklin's defection to the British, while Napoleon conquered the British mainland and forced the royalty to move to America. [Belongs in AlternateHistory.]

* By the end of ''Manga/NegimaMagisterNegiMagi'', there's at least three different timelines. The first one is the BadFuture Chao Lingshen comes from, the second one in which [[spoiler:Asuna goes into a sleep for 130 years]] and the third timeline where [[spoiler:Asuna is brought back in time to be with her friends this time around]] and at which the epilogue takes place. The sequel ''Manga/UQHolder'' takes place in the second timeline with glimpses at the third.

* ''Anime/PuellaMagiMadokaMagica'' shows that there is at least [[spoiler:five (and it is implied that MANY more occurred offscreen)]] of these as a result of [[spoiler:Homura Akemi trying to SetRightWhatOnceWentWrong]].
** ''Manga/PuellaMagiOrikoMagica'' confirms that there are [[spoiler: sixth and seventh]] canon timelines.
** ''Manga/PuellaMagiMadokaMagicaTheDifferentStory'' adds a [[spoiler: eighth]] one.
** [[VideoGame/PuellaMagiMadokaMagicaPortable The PSP game]] shows several additional timelines, though at least some aren't canon [[spoiler:due to Homura dying or becoming a witch.]]
** All the above only count those that are actually shown in-series -- WordOfGod states [[spoiler:Homura has reset the timeline at least 100 times.]]

* In the ''Magazine/DoctorWhoMagazine'' comic strip, the Eighth Doctor comic stories were initially explicitly depicted as taking place in an alternate timeline to most of the Seventh Doctor comic stories (Ace dies in a HeroicSacrifice at a point that is clearly before her character development in the Seventh Doctor stories, and the Seventh Doctor very quickly regenerates into the Eighth, with his first major story arc being his pursuit of the Threshold -- all this was because a [[ExecutiveMeddling new editor]] strongly disliked the Literature/DoctorWhoNewAdventures which the Seventh Doctor comics had shared a continuity with, and [[ArmedWithCanon wanted to demonstrate that]]). However, the post-2005 stories have occasionally made continuity references to stories from both allegedly separate timelines.

* In ''ComicBook/WonderWomanOdyssey'' Themyscira was destroyed when Diana was a young child, leading to the death of Hippolyta and Diana being raised in exile with surviving Amazons.

* {{Justified}} in ''Fanfic/BrotherOnBrotherDaughterOnMother'', which takes the approach of explaining the [[TimeyWimeyBall inconsistent behavior]] of ''Franchise/StarTrek'' TimeTravel with the notion that time is like a rope composed of alternate timelines (or more specifically sequences of probabilistically determined events) that are fundamentally similar overall, but which can fray off dramatically different timelines in the event of major temporal incursions. The TimePolice and the Temporal Prime Directive exist to prevent such frays from happening, since they damage time itself.

* ''Fanfic/SpiritLines'' takes place in an altered timeline of Part 1 to 6 of ''Manga/JojosBizarreAdventure'' after [[spoiler:Pucci used Made in Heaven to reset the universe in ''Stone Ocean'']]. While the events of ''Phantom Blood'' and ''Battle Tendacies'' remained the same, many events afterwards are changed, namely that in Part 3 Katarou (This timeline's Jotaro) and who is implied to Kakyoin get sick from Dio's influence, leading to Holly (who requests to go by [[MythologyGag Seiko]]) joining Joseph and Avdol on their quest to Egypt. Katarou and his daughter Irene, this timeline's Jolyne, are normal humans without Stands.

* The main setting of ''Fanfic/{{Odaliaverse}}'' is an alternate version of the Boiling Isles that, while initially looking very similar to the original timeline, is soon revealed to have a couple of changes, chief among them being [[spoiler:Phillip Wittebane having been petrified a long time ago, with someone else, implied to be his brother, taking his place as Emperor Belos.]]
* ''Fanfic/DownTheKarmicHole''' takes place in one, being set in the same universe as ''Fanfic/TheKarmaOfLies''. The main divergence so far is Alix encountering her alternate self's future self, Bunnyx, who informs her of the events that lead to ''Karma of Lies'' one week before they happen.

* Creator/IsaacAsimov's "Literature/LivingSpace": Alec Mishnoff is able to figure out that the German-speaking builders are from an alternate Earth timeline where UsefulNotes/NaziGermany won [[UsefulNotes/WorldWarII a tribal conflict]]. Still the same year, ignoring differences of [[AlternativeCalendar Nach Hitler versus Anno Domini]].

* ''Series/Maniac2018'' entirely takes place in a CassetteFuturism world where computing technology never advanced past about the late 1980s (WordOfGod is that [[http://www.vulture.com/2018/09/maniac-cary-fukunaga-patrick-somerville-interview.html "something happened in the '90s"]]). However in certain areas technology is more advanced, such as in VirtualReality and ArtificialIntelligence. Society also is more dystopian than ours. {{Blackmail}} apparently is common enough that there's a chain of stores called "Doxx Stop" that will give you enough information to blackmail someone. There's also the "Ad Buddy", who will pay for your goods in exchange for reading ads to you.

** In "A Stitch in Time", numerous alternate timelines are created due to time travel.
** In "Final Appeal", the sequel to "A Stitch in Time", Ezekiel tells the US Supreme Court justices that time travel has taught him that the future is malleable and, as a result, it is more accurate to talk about futures plural as he has witnessed several different timelines. He cites the example of an alien race launching a devastating retaliatory attack on Earth in the 24th Century in one of these timelines (as seen in "Relativity Theory") as evidence that technology is inherently evil and destructive to humanity. The events of other episodes presumably take place in different alternate timelines.

* ''VideoGame/StarcraftII'''s co-op modes are set in an (non-canon) alternate timeline where the fallen Xel'Naga, [[BigBad Amon]], successfully awakens and unleashes his hybrid army to wipe out all life in the universe, and the Terran, Zerg, and Protoss armies [[EnemyMine unite to stand against him]]. It also invokes a EveryoneLives as more co-op commanders were added, so you have someone like [[spoiler:Tychus and Mengsk]] alive for whatever reason.
* ''VideoGame/{{Stellaris}}'' allows players to forge their own history, but prior to the game's start there are three possible outcomes for the human race. In the main one the [[UnitedNationsIsASuperpower United Nations of Earth]] discovered FTL travel in the year 2200 and began colonizing the stars, with a LostColony ship potentially splintering off to form their EvilCounterpart the Commonwealth of Man. Then there's the [[TheComputerIsYourFriend Earth Custodianship]], where humanity surrendered our free will to robots that [[TheHedonist waited on us hand and foot]] while conquering the stars on our behalf. When playing as an alien empire, there's a 50% chance that humanity's development was delayed and we're fighting UsefulNotes/WorldWarII in the 23rd century, [[OutsideContextProblem making us ripe for invasion]].

** Only slightly below Lostbelt #6 is Lostbelt #7, Nahui Mictlan. The nail here has ''something'' to do with the asteroid that destroyed the dinosaurs. [[spoiler:As it turns out, it's that the asteroid arrived early and allowed humans to appear earlier in this timeline than they do in Proper Human History. The problem is that this meant there were humans around when [[Literature/AngelNotes ORT]], [[UltimateLifeForm the Ultimate One of the Oort Cloud]], showed up. In both timelines, ORT is called Gaia to destroy mankind when it appears they will outlive her, but in PHH, it shows up too early and thus goes into hibernation. Here, mankind was around when ORT landed, so ORT wasted no time in trying to obliterate us. It was only stopped when all of mankind sacrificed itself to empower the current king, Kamazotz, with immortality so that he could defeat ORT, and it still took ''a million years of non-stop fighting to do so'', and ORT ''still'' isn't dead. While unstated, it's heavily implied this world is ''also'' a Lostworld]].

** Titan Magazines had [[ComicBook/TransformersTwilightsLastGleaming a comic]] based off the [[Film/{{Transformers|2007}} 2007 film]] which diverges from the main timeline when the Decepticons win the Battle of Mission City.

** Titan Magazines had [[ComicBook/TransformersTwilightsLastGleaming a comic]] based off the [[Film/{{Transformers}} 2007 film]] which diverges from the main timeline when the Decepticons win the Battle of Mission City.

* ''[[https://archiveofourown.org/works/25658806/chapters/62291518 Adrien AUgreste: The New World After the Wish]]'' focuses on a new timeline created when Shadowmoth successfully gets the Ladybug and Black Cat Miraculous and make the wish to undo his wife's coma, [[EquivalentExchange which leads him to be in a coma instead and Emilie to become the Butterfly villain Lycaena]]. As Lycaena, she is a far more dangerous and ruthless villain than Hawkmoth was, forcing Master Fu to select more permanent heroes like Ryoko, Rena Rouge, and Pegasus to join in the fight alongside Ladybug and Chat Noir. In addition, Emilie [[AdaptationalVillainy is shown to be a skilled]] ManipulativeBitch, [[AbusiveParent using emotional manipulation to keep Adrien from going to public school]], getting the staff at Dupont [[AdultsAreUseless to be lenient towards bullies]] so more potential akumas can be made from the victism, having Marinette blacklisted as a designer so she couldn't claim the stolen hat design Chloe submitted, and training Lila as an apprentice who caused Marinette, Alya, and Max to expelled from their school, leading to the latter three to work in exposing the various corruption in Paris.

* ''[[https://archiveofourown.org/works/25658806/chapters/62291518 Adrien AUgreste: The New World After the Wish]]'' focuses on a new timeline created when Shadowmoth successfully gets the Ladybug and Black Cat Miraculous and make the wish to undo his wife's coma, [[EquivalentExchange which leads him to be in a coma instead and Emilie to become the Butterfly villain Lycaena]]. As Lycaena, she is a far more dangerous and ruthless villain than Hawkmoth was, forcing Master Fu to select more permanent heroes like Ryoko, Rena Rouge, and Pegasus to join in the fight alongside Ladybug and Chat Noir. In addition, Emilie [[AdaptationalVillainy is shown to be a skilled]] ManipulativeBitch, [[AbusiveParent using emotional manipulation to keep Adrien from going to public school]], getting the staff at Dupont [[AdultsAreUseless to be lenient towards bullies]] so more potential akumas can be made from the victism, having Marinette blacklisted as a designer so she couldn't claim the stolen hat design Chloe submitted, and training Lila as an apprentice who caused Marinette, Alya, and Max to expelled from their school, leading to the latter to three to work in exposing the various corruption in Paris.

** The original timeline shows Raiden and Shao Kahn as the final two kombatants in [[VideoGame/MortalKombatArmageddon the Battle of Armageddon]], with Kahn defeating Raiden. Knowing that he is about to be killed, Raiden sends a message to [[VideoGame/MortalKombat1 his past self]] [[SetRightWhatOnceWentWrong to hopefully change the future]], setting up the events of ''VideoGame/MortalKombat9''. The current timeline, while still near-identical to the original, [[spoiler:finally [[KilledOffForReal kills Shao Kahn for good]]. Unfortunately, the new decisions made and results [[PyrrhicVictory cost the lives of a lot of kombatants]], [[VideoGame/MortalKombatX made both Earthrealm and Outworld more vulnerable for attack]], and later on [[TheCorruption placed Raiden in a much darker state after Shinnok's defeat]]]].

** The ''Maximum Impact'' subseries is a nebulous example. While it appears to be a standalone AlternateContinuity wherein prominent characters from the first two arcs interact with a slew of fresh faces, the animated series ''Another Day'' [[ContinuityDrift incorporated elements]] of the then current Tales of Ash saga ([[VideoGame/TheKingOfFighters2003 Ash himself]], [[VideoGame/TheKingOfFightersXI Iori's loss of his cursed flames]]) despite being set after the events of the first ''Maximum Impact''. ''Regulation "A"'' (the UpdatedRerelease of ''Maximum Impact 2'') would then make Ash a playable character as well as introduce a CanonForeigner (Xiao Lon) who -- unlike the other ''MI''-exclusive fighters -- was designed specifically to provide ties to the main installments (being the younger half-sister of Duo Lon, a major supporting character introduced in ''2003''). Unlike the mainline and ''EX'' entries (but similar to the original ''Fatal Fury'' continuity), [[SchrodingersCast Geese is dead]], appearing in-series as his "Nightmare Geese" incarnation. (There's also the matter of his son [[VideoGame/GarouMarkOfTheWolves Rock]] appearing as a teenager, due to the series operating on ComicBookTime and Rock already appearing as a child in one of Terry's ''[[VideoGame/TheKingOfFighters2001 KOF 2001]]'' win poses, but the main games would eventually follow suit starting with ''[[VideoGame/TheKingOfFightersXIV XIV]]''.)

* While alternate timelines have been explored throughout the ''Franchise/{{Nasuverse}}'', the concept really took off in the second chapter of ''VideoGame/FateGrandOrder'', which focuses on the heroes trying to restore Proper Human History after an alien creature arrives and overrites history with seven alternatives, each known as a Lostbelt. They're ranked according to their Difference Depth, which defines how much they diverge from the proper history and, in turn, how dangerous they are for humans to survive in. Each timeline is guarded by a Crypter, the custodian of the new world.