History Main / ExpendableAlternateUniverse

* The 2001 film ''Film/TheOne'' is about an interdimensional criminal who's been going through every universe and killing his counterparts to steal their lifeforce, and is down to the last one (ours). Grave consequences are implied if there's only one of one person in the multiverse. Notably, this is a rather constrained multiverse: it is explained that every time a sun turns into a black hole (or something like that) a new universe is created and so far this has happened 125 times. At the very end of the movie, the villain is sent to the "Hell Universe" which serves as a jail for all the others... [[ScifiWritersHaveNoSenseOfScale there's an entire universe dedicated to being a prison system]]. No mention of the original inhabitants or what became of them.

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[[quoteright:350:[[ComicBook/DeadpoolKillsTheMarvelUniverse https://static.tvtropes.org/pmwiki/pub/images/dpoolkills.jpg]]]]

* ''FanFic/CoreLine'' [[ZigZaggedTrope Zig-Zags the trope]]. In the aftermath of a multi-versal collision (which created the setting) it is obvious that many people believe this (and there's [[TerroristsWithoutACause even a terrorist faction]] (the "Knights Of The True Timeline") that takes it to its InUniverse logical extreme, exterminating Alternates of people willy-nilly), there are a great many who come from those Alternate Universes that scream that (Dimensional) ClonesArePeopleToo.
* Subverted in crossover ''Fanfic/EchoesOfYesterday'', where ComicBook/{{Supergirl}} gets dragged into [[Literature/{{Worm}} Earth-Bet]]. Kara misses and wants to go back home badly, but after finding out via a bit of fact-checking what kind of CrapsackWorld she has landed into, she decides she must do everything in her power to help.

* ''FanFic/TheInfiniteLoops'' has Loopers refer to this attitude as Sakura Syndrome, and generally frown upon it. Yes, reality is stuck in a time loop but not only will your fellow loopers remember your actions, if you break the world too hard you might wind up in the Eiken Loop [[spoiler:or accidentally [[RetGone destroy your universe.]]]]

* Discussed in ''Fanfic/WhatTomorrowBrings''. Chapter 53 begins with [[spoiler:a flashback where Cassie asks Jake why he wants to go back to the original timeline and leave the splinter universe to die. Jake responds that it's the only way to make the splinter universe stable again, and that he gave the morphing cube to James.]]
* ''Series/TheFlash2014''/''Series/Supergirl2015'' crossover ''Fanfic/CallMeKara'' averts this. Even though [[ComicBook/{{Supergirl}} Kara]] was effectively betrayed by her home dimension, she still cares about what happens to it, and when ComicBook/{{Darkseid}} shows up both she, [[Franchise/TheFlash Barry]] and the whole Justice League go to her Earth to fight.
* Not explicitly stated, but speculated in "[[https://www.fanfiction.net/s/12397789/1/League-of-two-Earths-new-world League of Two Earths]]" when Oliver, Barry, Kara and their allies realise that Earths 1 and 38 have been merged into one universe. As far as the wider world is concerned, Star City, Central City and National City have always existed on the same Earth and their heroes’ respective team-ups still took place, but [[RippleEffectProofMemory only those who directly interacted with people from the other worlds before the merge still remember the original course of events]]. The heroes eventually determine that when their worlds merged, anyone with counterparts on both Earths would have merged into one person with the ‘stronger’ counterpart taking precedent, so essentially the weaker counterpart, whether from Earth-1 or Earth-38, has ceased to exist as an independent entity.
* ''VideoGame/ChronoTrigger: VideoGame/CrimsonEchoes'' has three timelines, the one that was created after the BigBad from the original game died, one where the myths of [[CoolSword a certain legendary sword]] never existed, and one that was mentioned in the official sequel ''VideoGame/ChronoCross'', where the aforementioned BigBad was not around to influence evolution and a long-dead race was revived to wage war on the now-ordinary humans. This fan-game's [[TheWatcher Watcher]] kinda doesn't like that these alternate timelines exist, as his workers, if you did something to muck up the timeline to make it different from normal, will not allow you to return to base until you make the necessary changes that keep history on track.
* Taken up to BlueAndOrangeMorality levels by "A.K." in ''[[http://www.fanfiction.net/s/2829366/1/ Dimension Hopping For Beginners]]'', who hunts down each dimension's [[BigBad Lord Voldemort]] and sometimes helps the Harry Potters he meets along the way, but other times 'helps' others inappropriately, like dumping a justifiably angsty version in an army boot camp to 'toughen up' rather than helping him appropriately resolve his emotional trauma, or even worse, by killing any Harry Potter who he disapproves too strongly of (such as one [[SlashFic in love with]] Draco Malfoy). In his own words:
-->'''A.K.''': It's not every Harry Potter I've let live.
** Although this is also a case of A.K. just being an [[JerkAss ass]][[AntiHero hole]] with MoralMyopia, as he [[WhatTheHellHero has a (justified) go at the Wizarding World]] for the treatment which caused one version of Harry Potter to become the Dark Lord Levicordus, and goes to quite great lengths to help some of the other versions, but seemingly has a rule of killing any Harry Potter in love with Draco Malfoy, and also advises another Harry that "[[MurderIsTheBestSolution Avada Kedavra is cheaper than a divorce lawyer]]".
* In ''Fanfic/HarryPotterAndTheNightmaresOfFuturesPast'', Harry acknowledges that sending his memories back to his eleven-year-old self from a timeline where society has basically collapsed after the war against Voldemort went on until he was thirty will either create a new reality or destroy the one he exists in, but Harry is so broken after seeing virtually everyone else he ever knew die that he doesn't care and the only other person he can talk to (Dumbledore's portrait) accepts that he can either help Harry with this last plan that might save some people, or just wait until Harry becomes so depressed he kills himself.
* In ''Fanfic/AloneTogether'', Kim falls back on this concept as a way of distancing herself from increasingly disturbing realizations about her experiences in the Other World, telling herself that those things happened to another version of her, not her real self. This rationalization breaks down during a phone call from Shego, who clearly sounds like the friend and lover she knew in the Other World rather than the Arch-Enemy she knew in this one.
* ''Webcomic/FeralnetteAU'': This mentality is [[DeconstructionFic heavily deconstructed]].
** Due to how TimeTravel works in this series, [[https://bigfatbreak.tumblr.com/post/667448883471925248/ there's only one]] [[TimeMaster Bunnyx]], who comes from the canonical setting of the show. Unfortunately, Alix believes this means that there's only One True Timeline, and that any deviations from that path, no matter how minor, are anomalies she needs to stamp out. To her mind, all other universes, and the inhabitants thereof, are innately disposable; they aren't ''HER'' friends, family, or the like, and thusly don't ''matter'' to her.
** Bunnyx also [[NiceJobBreakingItHero played a key role]] in this 'verse's AU having a breakdown. Not only did she needlessly harass, blame and berate her over minor differences that didn't actually threaten anything, she dragged her into the BadFuture and made ''her'' deal with Chat Blanc, [[TheScapegoat blaming her for his existence]]... and forcing Marinette face to face with a doomed version of herself. The trauma of watching her own ashen corpse dissolve away, coupled with the constant pressure of being blamed for everything that went wrong, led to Marinette deciding to remove herself from the equation as much as possible and focus entirely on her duties as Ladybug.
** Bunnyx is also ''continuing'' to harass 'Feralnette', claiming she wants to [[SetRightWhatOnceWentWrong set things right]]... but still insists on this being entirely on ''her'' terms, trying to make her act more like 'her' Marinette.
* ''[[Fanfic/RecklessnessMiraculousLadybug Recklessness]]'' features a variant: since Alya intends to use the [[RealityWarpingIsNotAToy reality-rewriting Wish]] to [[MundaneUtility learn who Hawkmoth is]], she figures that nothing she does to obtain the Miraculi she needs to make said Wish will actually ''matter'' -- it'll all be retconned out of existence anyway, right? So she isn't phased by how her betrayal causes [[spoiler:Adrien's akumatization and Marinette's demise]], even brushing off the anguished reactions of others to these events as 'unnecessarily dramatic'. Sure, ''they'' don't know that it's all about to be wiped away, but there's still no reason for anyone to [[spoiler:weep over their daughter's corpse]], right?
* Applejack's reharmonizing chapter in the ''Fanfic/PonyPOVSeries'' has her seeing a large number of these staring into the Truth, a pool that shows the viewer all kinds of uncomfortable truths. She sees the BadFuture presented in "Epilogue" along with others. The most heartbreaking is the "Orangejack" timeline, where she discovers that she could've lived perfectly happily without returning home and met the love of her life, even having children. She's heartbroken at the realization her children won't exist because of her choice, until Celestia reveals that universe still exists and they'll live on in that path.
* ''Fanfic/ACrownOfStars'': {{Subverted}}. In this story Shinji and Asuka discover the existence of a whole multiverse full of alternate universes and parallel realities. Upon arriving in Avalon, they meet some of their alternate selves and hear about other worlds similar to theirs. However, the rulers of Avalon treat all of them as an important deal.
* In ''Fanfic/{{Ancienverse}}'', [=DARC=] regards the main universe as useless and expendable.
* ''The Converging Series'' (sequel to ''Descents and Inversions''): the non-canon main characters are accidental time travellers from different alternate futures who are descended from various pairings of the canon characters. While the OnlySaneMan recognizes the existence of coexisting alternate realities (having had to deal with his reality-hopping amazon "half-sister" in the prequel), all the others decide to force the current reality into their own, to ensure their own continuous existence.
* Goes back and forth in ''[[https://www.fanfiction.net/s/12122558/1/Mirror-World Mirror World]]'', as the story starts when Sam is abducted by a syndicate of hunters from a parallel reality because they want to analyse him to see if he has the immunity to Eve demonstrated by their version of Sam. Not only do these hunters not bother to explain why they want him or check to see if he has that immunity before they capture him, they treat him more like a thing than a person, showing no sign that they care about anything he might have to contribute based on his own experiences in his reality. By contrast, after Dean and Castiel follow the Syndicate to their world to rescue Sam, [[spoiler:rather than abandon that world to its fight against Eve, Dean and Castiel help the Syndicate assemble the weapon he and Cas used against the Leviathans to kill the Eve of this reality, with the alt-Gwen Campbell- alt-Sam's closest friend- ashamed that it took two men from another world to make the Syndicate see how far it had fallen]].

* Played straight in ''[[https://m.fanfiction.net/s/11860936/1/ Betrayed]]'', somewhat surprisingly considering the fic's theme that actions taken before a RESET aren't expendable or necessarily forgivable. Several alternate timelines where Frisk acted differently are visited, all of which except the Pacifist timeline are far worse than the main one, whether because Chara reignited the Human-Monster War and it ''didn't'' fizzle out, or because Frisk is a psychopath who enjoys killing monsters and returned to the Underground to finish the job, or has a LackOfEmpathy and kept the monsters trapped and in anarchy ForTheLulz. Moreover, Gaster takes souls from other timelines on a regular basis, not caring that doing so incites wars interdimensional in scope. He also brings warriors from nasty timelines to more peaceful ones. The heroes go to great lengths to repair the damage done to their own timeline, but don't even try to fix the others that are just as bad or worse, though admittedly they have the "one can't fix an infinity of worlds" excuse.

** On the other hand, [[spoiler:once Evelyn decides to be TheAntiNihlist, she goes out of her way to return to a few universes she'd previously visited to fix the problems she'd created there, deciding that even the more bizarre universes shouldn't be just written off.]]
* The 2001 film ''Film/TheOne'' is about an interdimensional criminal who's been going through every universe and killing his counterparts to steal their lifeforce, and is down to the last one (ours). Grave consequences are implied if there's only one of one person in the multiverse. Notably, this is a rather constrained multiverse: it is explained that every time a sun turns into a black hole (or something like that) a new universe is created and so far this has happened 125 times. At the very end of the movie, the villain is sent to the "Hell Universe" which serves as a jail for all the others... [[ScifiWritersHaveNoSenseOfScale there's an entire universe dedicated to being a prison system]]. No mention of the original inhabitants or what became of them.
* ''Film/MenInBlack3'': Griffin is an alien capable of seeing all timelines at once, though he's not certain which one he's in. This means that he's often fretting whether or not this is the timeline that something disastrous happens based on [[ForWantOfANail minor actions that seem insignificant to others]] (such as Boris being delayed at traffic lights or Kay leaving a tip for pie).
* ''Film/Cube2Hypercube'': A group of people are trapped in a giant maze of interconnected cubical rooms which also has distorted AlienGeometries and intersecting parallel universes. One character eventually becomes [[AxCrazy violently insane]] from the stress and hunger. He solves his food problem by repeatedly [[NoPartyLikeADonnerParty hunting down and eating]] alternate versions of the people in the hypercube.
* Played with in the movie ''Film/StargateContinuum''. The team gets sent to an alternate timeline where the stargate was lost at sea and the SGC was never founded. When they suggest that they use the stargate to travel back in time and set things back the way they were, the alternate universe Landry chews them out for thinking they had the right to alter the lives of every human on the planet. [[spoiler:They wind up having to do this to save Earth by the end of the movie anyway; it just took a year or so for a suitable threat to turn up.]]

** In the ''Series/StarTrekStrangeNewWorlds'' episode "[[Recap/StarTrekStrangeNewWorldsS2E03TomorrowAndTomorrowAndTomorrow Tomorrow and Tomorrow and Tomorrow]]" La'an is thrown into an alternative timeline where Earth never became enlightened and the Federation never formed. She [[meets an alternate James T. Kirk and they are both thrown back to the early twenty-first century. Initially, Jim resists her mission to "fix the timeline" because he doesn't want to harm his friends or his reality. But he gradually recognizes his is a CrapsackWorld and starts to help La'an.]]

* In the ''Series/StarTrekStrangeNewWorlds'' episode "[[Recap/StarTrekStrangeNewWorldsS2E03TomorrowAndTomorrowAndTomorrow Tomorrow and Tomorrow and Tomorrow]]": La'an is thrown into an alternative timeline where Earth never became enlighted and the Federation never formed. She [[meets an alternate James T. Kirk and they are both thrown back to the early twenty-first century. Initially, he resists her mission to "fix the timeline" because he doesn't want to harm his friends or his reality. But he gradually recognizes his is a CrapsackWorld and starts to help La'an.]]

* In the ''Series/StarTrekStrangeNewWorlds'' episode "[[Recap/StarTrekStrangeNewWorldsS2E03TomorrowAndTomorrowAndTomorrow Tomorrow and Tomorrow and Tomorrow]]: La'an is thrown into an alternative timeline where Earth never became enlighted and the Federation never formed. She [[meets an alternate James T. Kirk and they are both thrown back to the early twenty-first century. Initially, he resists her mission to "fix the timeline" because he doesn't want to harm his friends or his reality. But he gradually recognizes his is a CrapsackWorld and starts to help La'an.]]

* In the ''Series/StarTrekStrangeNewWorlds'' episode "Tomorrow and Tomorrow and Tomorrow: La'an is thrown into an alternative timeline where Earth never became enlighted and the Federation never formed. She [[meets an alternate James T. Kirk and they are both thrown back to the early twenty-first century. Initially, he resists her mission to "fix the timeline" because he doesn't want to harm his friends or his reality. But he gradually recognizes his is a CrapsackWorld and starts to help La'an.]]

** The show had an inverted version of this: in an alternate universe where Lex Luthor kills The Flash, Superman returns the favor, and the Justice League becomes the "Justice Lords," a totalitarian force that [[UtopiaJustifiesTheMeans ensure peace and justice by suppressing dissent]] and [[MindRape lobotomizing]] former villains. When they find out about the series' main Earth, they decide to head over, incapacitate the Justice League, and "show them the light". The Justice League's response is a pure embodiment of this trope: they depower the Justice Lords and apparently stick them in prisons on the Justice League's Earth. So much [[PoliceAreUseless for]] ''[[HoldingOutForAHero that]]'' [[TheWorldIsAlwaysDoomed world]]. (They still have their Batman, though. They'll be fine.)
** Averted in the first SeasonFinale. Before traveling back in time to stop Vandal Savage's plan to TakeOverTheWorld the team warn Alternate Batman that:

** There's also an episode where Superman is seemingly killed (in fact, thrown into the far future), and without him the Justice League fails to stop another plot by Vandal Savage. This doesn't turn out the way Savage planned and instead wipes out nearly all life and hideously mutates the rest - except for Savage himself, who is immortal. After living alone for centuries in the literal hell on Earth he created, Savage comes to regret his villainy, and teams up with Superman to [[SetRightWhatOnceWentWrong prevent himself from defeating the Justice League]] by sending Superman back in time. Superman asks the heroic version of Savage what that means for him, but he considers that an acceptable sacrifice. Once they succeed, the heroic Savage contentedly fades away, assumably leaving only the usual supervillain version.
** In the not-officially-related ''WesternAnimation/JusticeLeagueCrisisOnTwoEarths'' when Batman's EvilCounterpart Owlman learns that every time anybody anywhere makes any kind of choice, a new universe is created for each possible option chosen, [[spoiler:he decides that not only do other universes not matter, neither does his own, because any choice he makes is meaningless. After all, in another universe he automatically made a different one. He resolves to destroy Earth-Prime to destroy the multiverse, viewing it as "the only possible ''real'' choice" anyone could ever make. Batman manages to send both him and his bomb into an actually expendable universe where Earth has become a frozen wasteland devoid of all life]].
* In ''WesternAnimation/PeterPanAndThePirates'', one episode has Peter and the gang entering an alternate universe where copies of Peter Pan, Wendy and the Lost Boys are slaves, toiling endlessly to prevent the Corc (their version of the crocodile that Captain Hook and everyone else are afraid of) from awakening. Peter Pan et al have an adventure in this alternate universe, but are unable to save these copies of themselves from their lifetime of misery and slavery. The copies help the originals escape, and that's it.

[[index]]
* ExpendableAlternateUniverse/AnimeAndManga
* ExpendableAlternateUniverse/ComicBooks
* ExpendableAlternateUniverse/FanWorks
* ExpendableAlternateUniverse/{{Literature}}
[[/index]]

[[folder:Films -- Live-Action]]
* ''Film/EverythingEverywhereAllAtOnce'': Lampshaded by Evelyn, who asks why they can't just let a few alternate universes be lost to Jobu Tapaki. Waymond tells her that Jobu Tapaki is planning something much worse that could threaten the ''entire'' multiverse.
** That being said, he asks Evelyn to think strongly about going into the janitor's closet after exiting the elevator to deliberately create an alternate “burner” universe where she did so they have somewhere to talk after initiating her into verse jumping. This reality acts as a decoy to Jobu Tupaki and her forces to buy themselves time before Evelyn has to confront her.
** On the other hand, [[spoiler:once Evelyn decides to be TheAntiNihlist, she goes out of her way to return to a few universes she'd previously visited to fix the problems she'd created there, deciding that even the more bizarre universes shouldn't be just written off.]]
* The 2001 film ''Film/TheOne'' is about an interdimensional criminal who's been going through every universe and killing his counterparts to steal their lifeforce, and is down to the last one (ours). Grave consequences are implied if there's only one of one person in the multiverse. Notably, this is a rather constrained multiverse: it is explained that every time a sun turns into a black hole (or something like that) a new universe is created and so far this has happened 125 times. At the very end of the movie, the villain is sent to the "Hell Universe" which serves as a jail for all the others... [[ScifiWritersHaveNoSenseOfScale there's an entire universe dedicated to being a prison system]]. No mention of the original inhabitants or what became of them.
* ''Film/MenInBlack3'': Griffin is an alien capable of seeing all timelines at once, though he's not certain which one he's in. This means that he's often fretting whether or not this is the timeline that something disastrous happens based on [[ForWantOfANail minor actions that seem insignificant to others]] (such as Boris being delayed at traffic lights or Kay leaving a tip for pie).
* ''Film/Cube2Hypercube'': A group of people are trapped in a giant maze of interconnected cubical rooms which also has distorted AlienGeometries and intersecting parallel universes. One character eventually becomes [[AxCrazy violently insane]] from the stress and hunger. He solves his food problem by repeatedly [[NoPartyLikeADonnerParty hunting down and eating]] alternate versions of the people in the hypercube.
* Played with in the movie ''Film/StargateContinuum''. The team gets sent to an alternate timeline where the stargate was lost at sea and the SGC was never founded. When they suggest that they use the stargate to travel back in time and set things back the way they were, the alternate universe Landry chews them out for thinking they had the right to alter the lives of every human on the planet. [[spoiler:They wind up having to do this to save Earth by the end of the movie anyway; it just took a year or so for a suitable threat to turn up.]]
* Franchise/MarvelCinematicUniverse:
** ''Film/AvengersEndgame'': Subverted. When Bruce [[spoiler:shows up in the past to take the Time Stone]] from the Ancient One, she refuses, as it will doom her branching universe to extinction. Bruce promises that, with time travel, they can bring it right back to the same instant it was taken (whether that will cause her timeline to merge back into the main one or continue as a branch that isn't doomed to extinction [[TimeyWimeyBall is unclear]]). She initially refuses, since they could die before they have a chance to put the stone back, but she accepts it once she hears that her successor, Doctor Strange, is the one who made the plan possible. At the end of the movie, Steve uses the time machine again to put everything back where it's supposed to be.
** ''Film/SpiderManNoWayHome'' [[spoiler:subverts this ''and'' combines it with SaveTheVillain]]. Upon learning from Strange that [[spoiler:all the villains pulled into the Marvelverse are doomed to die]] back in their own worlds, [[spoiler:[=MCU=] Peter Parker stops Strange from sending everyone back until he can alter the fates of the rogues from the Franchise/SpiderManTheatricalFilms and Franchise/TheAmazingSpiderMan universes]].
** ''Film/DoctorStrangeInTheMultiverseOfMadness'': Defied. [[spoiler:Wanda's]] goal is to kill America Chavez, a child from another universe who has the power of inter-dimensional travel, and steal her powers. That way, [[spoiler:she can travel to an alternate universe where her children are alive & KillAndReplace her alternate self so she can have her happy family life.]] Doctor Strange and Wong rightfully say throughout the film how horrible from both a safety and moral standpoint this plan is. Additionally, [[spoiler:Strange's AlternateUniverse counterpart is summarily executed by the rest of his team [[MyGodWhatHaveIDone after he confesses]] that his actions inadvertently led to the destruction of two other universes]]. PlayedStraight with the fate of ComicBook/TheIlluminati however, a superteam from another universe that try to stop the villain and are all brutally slaughtered for their trouble, which [[AssholeVictim garners no sympathy from anyone in the main universe]].

[[folder:Live-Action TV]]
* ''Series/{{Arrowverse}}:''
** ''Series/{{Arrow}}''. Averted in Season 8 when the deaths of everyone on Earth 2 is treated with the appropriate depth. In particular, the episode focuses on Laurel's grief over the loss of her entire universe and everyone she loved. The Monitor on the other hand treats the destruction of Earth-2 as a "necessary sacrifice", showing little regard for the lives lost and simply warning that it was just a taste of what the Anti-Monitor is capable of; the only person who could or would treat the loss of an entire universe with such detachment is a godlike being who has an infinite number of universes to consider.
** ''Series/TheFlash2014'':
*** Deconstructed. The heroes from the main setting of Earth 1 always consider Earth 2 just as legitimate as their own world, but the opposite isn't true as Earth 2 super villain Zoom takes to sending other Earth 2 villains to Earth 1 to kill the Flash. Several of them start out by tracking down their own counterpart and killing them, and even one who's explicitly stated to have never killed anyone before has no problem pulling a KillAndReplace on her counterpart to escape Zoom (though she's horrified when she accidentally kills someone else instead).
*** In the episode "[[Recap/TheFlash2014S2E9RunningToStandStill Running to Stand Still]]", Earth-2 Harrison Wells sends hundreds of bombs through a wormhole to an alternate dimension. No one seems to consider the bombs might be raining down on a bunch of their alternate selves.
*** After the breaches are closed, Wells' daughter is rescued [[spoiler:and the apparent death of Jay Garrick]], Barry is told to forget about Earth 2 and move on with his life, saying that Earth 2's world is not his own to worry about. However, after seeing firsthand what it suffers at Zoom's hands, Barry feels guilty for leaving it at his mercy and vows to liberate it from Zoom.
*** The season 2 finale involves [[spoiler:Zoom deciding to eliminate every world in TheMultiverse besides Earth 1 (he still needs someplace to live, after all), forcing Barry to help him generate enough power for the device. However, Barry is determined to prevent that so much that he creates a time remnant for the sole purpose of the latter performing a HeroicSacrifice. In effect, Barry is willing to give his own life in order to save countless billions]].
*** Season Two also made the old ''Series/TheFlash1990'' show part of the universe, and it would be given the designation Earth-90. But it didn't become important to the plot until the 2018 crossover ''Series/{{Elseworlds|2018}}'', where it's revealed that the Monitor slaughtered the whole Earth and every hero, except the Flash.
** In ''Series/LegendsOfTomorrow'' Season 2 finale, the Doomworld!Legends find themselves on the receiving end of this. They travel back in time to prevent the Legion of Doom from getting the Spear of Destiny and creating [[VillainWorld Doomworld]], and acknowledge that if they are successful they will be erased from existence. [[spoiler:They then get themselves killed fighting the Legion ensuring their counterparts successfully escape with the Spear until only Sara is left, who then peacefully winks out of existence.]]
** Much like in the story it's based off of, ''[[Series/CrisisOnInfiniteEarths2019 Crisis on Infinite Earths]]'' wipes out many worlds based off other live action adaptations of DC Comics to raise the stakes. Among the victims include [[Film/Batman1989 Tim Burton's Batman]], ''Series/Titans2018'', [[Series/CrisisOnEarthX Earth-X]], [[Series/Batman1966 the '60s Batman series]], and ''Series/BirdsOfPrey2002''. Tie-in comics also add the ComicBook/New52, [[Series/WonderWoman1975 the '70s Wonder Woman series]], and the WesternAnimation/SupermanTheatricalCartoons by Creator/FleischerStudios.
* ''Series/BuffyTheVampireSlayer'':
** Played reasonably straight in the episode "[[Recap/BuffyTheVampireSlayerS3E9TheWish The Wish]]". By the end of the episode, Giles and Oz are the only main characters left alive; then Giles manages to hit the ResetButton and restore the original universe, accepting the erasure of his own world because the other reality ''has'' to be better.
** In the follow-up episode "[[Recap/BuffyTheVampireSlayerS3E16Doppelgangland Doppelgangland]]", the heroes have no problem with returning Vampire Willow to her own universe rather than staking her, even though she's killed people there in the past and fully intends to continue killing people once she gets back, apparently it's okay because she's not hurting anyone from our Buffyverse and Willow thinks she's kind of cool. She ended up being staked by Wishverse Oz almost immediately after returning to her universe, but the heroes had no way of knowing that would happen.
* ''Franchise/StarTrek'':
** Almost every ''Star Trek'' series had at least one episode where a NegativeSpaceWedgie produces a horror world, and everybody dies fixing the problem, but then our world [[SnapBack Snaps Back]], so all is well. (For instance, the ''Series/StarTrekTheNextGeneration'' episode "[[Recap/StarTrekTheNextGenerationS3E15YesterdaysEnterprise Yesterday's Enterprise]]" and the ''Series/StarTrekVoyager'' episode "[[Recap/StarTrekVoyagerS4E8YearOfHell Year of Hell]]".)
** A downplayed example, where the death of an alternate is treated as acceptable but still tragic, is the ''Series/StarTrekTheNextGeneration'' episode "[[Recap/StarTrekTheNextGenerationS7E10Parallels Parallels]]". A NegativeSpaceWedgie rips a hole in time, and five billion plus Starships Enterprise need to get back to their home dimensions. This takes place in a second (for lack of a better term) universe where Riker is captain, and he leads the effort to fix the hole. Then a third Riker tries to stop him -- the third Riker is crazed, from a horrible universe where the Borg have conquered the galaxy, and doesn't want to go back. The second Riker has his ''Enterprise'' fire on the third, intending to dissuade it, but the travails of the third ship had already done such a number that even a light shot blew it apart. Riker isn't happy. The {{Technobabble}} that ends the episode is effectively a ResetButton, and while Worf retains his memory of it, it effectively didn't happen.
** Seen in ''Series/StarTrekVoyager''. A time-space hiccup causes there to be two Voyagers in the same place at the same time drawing off the same power source. One of the Harry Kims is killed (and one of the Naomi Wildmans dies not long after being born), so the other Voyager sends their Kim and Naomi to the functioning ship before self-destructing to take out an invading alien force. Naomi and Harry's status as alternates is never mentioned again. This is somewhat an inversion of the trope, since it is implied that the destroyed Voyager is the "real" Voyager of the series! (Though this, too, is never again mentioned.)
** In ''Series/StarTrekDeepSpaceNine'', there is an episode where Time Travel Disease keeps sending O'Brien forward in time to see himself die. (See: O'Brien Must Suffer.) He goes to great lengths to save himself each time until the disease kills him, at which point Alternate Timeline O'Brien goes back in his place to save the station. In a subversion of the main trope, Alternate O'Brien feels very bad about Regular O'Brien's death.
** Another ''[=DS9=]'' episode seriously looks at this trope, where the ''Defiant'' crew learns that, thanks to the TimeyWimeyBall, they'll soon crash-land hundreds of years in the past on an isolated planet. While their descendants will form a thriving colony of 8,000 people, the crew themselves will inevitably die on the planet (save for the long-lived Odo) and never see their family and friends back home, and Kira will die shortly after the crash. Sisko really doesn't want to strand his crew, and knows they could easily avoid the accident now, but that would RetGone the entire colony, effectively killing thousands of people. Ultimately, the crew reluctantly decides to subvert the trope at their own expense and go through with the crash -- only for the older version of Odo to forcibly make the ship escape and erase the entire colony, all to prevent Kira from dying. Kira herself is ''horrified'' when she learns about this, especially as she'd made peace with dying for the sake of preserving lives.
** This gets reversed in ''Series/StarTrekDiscovery'', where a MirrorUniverse character makes it clear that he considers ''his'' universe the "real world" and the heroes' universe as expendable.
** Downplayed in the ''Series/StarTrekTheOriginalSeries'' episode "[[Recap/StarTrekS2E4MirrorMirror Mirror, Mirror]]". Kirk cares enough about the denizens of the Mirror Universe to try and convince the crew of the Mirror Enterprise, and especially Mirror Spock, to give up their violent and authoritarian ways, but it's still treated as less important than returning the trapped crew members from his home universe.
* ''Series/{{Heroes}}'':
** The episode "Five Years Gone" is set in a dark future with a high body count, none of which will matter if our heroes prevent the dark future from happening.
** In season two, Peter visits a future where ''93% of the population'' is dead. That is, the human population. Of Earth. The planet. This is made worse by the fact that Peter's girlfriend is abandoned there when his powers deposit him back in the 'present'. So he attempts to save her by stopping that future happening. In Season 3, [[spoiler:Peter's apparently forgotten that she ever existed...]]
** Season 3 introduced ''yet another'' possible ugly future which contains, among other things [[spoiler:Hiro's (apparent) death at the hands of his best friend Ando, Claire killing Peter, and a redeemed Sylar cratering Costa Verde (and killing Matt's future wife in the process) when his own son is killed and he loses control of Ted's powers. Also the mass proliferation of super-people has the Earth primed to ''EXPLODE'']], But none of it has happened ''yet''. Neither will it happen, since that future is dead as well. [[spoiler:We seem to be locked on target for Five Years Gone, however...]]
* Oh, ''Series/StargateSG1''...
** In the alternate universe seen in "[[Recap/StargateSG1S1E19ThereButForTheGraceOfGod There but for the Grace of God]]", the Goa'uld actually succeed in conquering Earth and killing the counterparts of SG-1 (except for Teal'c, who never defected from Apophis in this universe). (Teal'c got to die offscreen when the base was programmed to [[SelfDestructMechanism self-destruct]].)
** As an exception, "[[Recap/StargateSG1S3E6PointOfView Point of View]]" had "our" team travel to an AlternateUniverse to help stop the Goa'uld invasion of Earth (although they still did it only after they found out that the alternate Samantha Carter couldn't stay in their universe). Although, oddly, this episode, while not following the trope, does explicitly state it. Teal'c (rather nonchalantly) kills his alternate, and when he's questioned about it by his (incredibly freaked out) teammates, he doesn't hesitate to matter-of-factly state "ours is the only reality of consequence". While this seems unusually callous of Teal'c, FridgeBrilliance may be relevant: he's TheAtoner, so he would be particularly willing to kill a version of himself who was still guilty of what the "real" Teal'c was trying to atone for.
** The episode "[[Recap/StargateSG1S4E162010 2010]]" sees the SG-1 of the year 2010 (ten years in the future of the time the episode aired) come up with a plan to erase their timeline, despite having defeated the Goa'uld with the aid of their allies the Aschen, because they've learned that the Aschen are sterilizing ninety percent of Earth's population to make humanity their slaves, with the Tau'ri lacking the resources to oppose the Aschen on their own and concluding that the only way to stop them is to prevent this alliance from ever being formed in the first place.
** "[[Recap/StargateSG1S9E13RippleEffect Ripple Effect]]":
*** Alternate Dr. Frasier (who somehow only popped up in one of the 20+ SG-1 teams along with Carter's snake-brained love-interest Martouf; both are dead in "our" world) comes from a version of Earth where the Ori plague was still ravaging the world and a cure was still unfeasible. Alternate Frasier outright demands that her reality be taken seriously by Stargate Command, and she receives help (the cure) from them.
*** The episode does also follow...or perhaps invert the trope: one of the other [=SG1=] teams is planning to sacrifice "Earth-1" to save their own Earth. Technically, the other SG-1 wasn't planning on sacrificing Earth-1. They just wanted to save ''their'' Earth by getting the prime universe's ZPM, figuring that a three-week ride on the ''Daedalus'' instead of an Earth-to-Atlantis gate wasn't too bad. (SG-1 of the prime Earth argued that the ZPM was also needed to power the city's shield and other defenses, but their alternates weren't really bothered about that). On the other hand, once the alternate SG-1 is stopped and sent back, the prime SG-1 team doesn't seem very concerned about the alternate Earth still lacking adequate defenses against the Ori.
** Subverted in the audiobook "Gift of the Gods", which revealed that Daniel Jackson from "our" universe was KilledOffForReal before the episode "Fair Game" and replaced by an alternate universe counterpart.
** The main role of O'Neill's friend Major Kawalsky is to die in every single timeline, whether they find it or create it with time travel. (Except for [[spoiler:"Point of View", the aforementioned exception to this trope, which is the only one where he survives]].)
** In the season 10 episode "[[Recap/StargateSG1S10E13TheRoadNotTaken The Road Not Taken]]", Carter and her counterpart in another universe are experimenting with an Ancient device simultaneously. Something goes wrong and our Sam is transported to the other side. The other Sam wasn't so lucky. No one from the other side seems too upset about this, whereas our SG-1 is extremely worried for the duration of our Sam's absence.
* ''Series/StargateAtlantis''
** Subverted in "[[Recap/StargateAtlantisS03E08McKayAndMrsMiller McKay and Mrs. Miller]]"; the techies have no qualms doing great damage to an alternate reality until they find out that life also exists in it (a chance that was considered astronomically small).
** Subverted in "[[Recap/StargateAtlantisS05E04TheDaedalusVariations The Daedalus Variations]]"; the team is stuck on an alternate reality ''Daedalus'' which is jumping through different realities. In one reality, an unknown alien race starts attacking Atlantis. Sheppard insists on intervening, convinced that this reality's Atlantis are still the "good guys". It leads to the aliens attacking them as well, but the alternate Atlantis helps, so it works out. Played straight with Ronon however. Teyla at one point wonders if her dead counterpart had a child as well only for Ronon to say worrying about every single reality's Teyla and her child is pointless.
** The penultimate episode, "[[Recap/StargateAtlantisS05E19Vegas Vegas]]", is [[AlternateRealityEpisode set in a separate alternate universe]] where Sheppard is a CSI-style detective in Las Vegas hunting down a rogue Wraith that somehow got to Earth. However, before the Wraith dies, it transmits a signal throughout the multiverse shouting Earth's location. The alternate Woolsey's response to this is that it's pointless to worry about saving every possible universe and is sufficiently pleased to have prevented the invasion in his own. Unfortunately for the primary versions of the cast, the message makes it to their universe, setting up the finale.
* ''Series/{{Sliders}}'':
** The show both avoids and endorses this trope through its first two seasons. Despite an agreement not to interfere with the worlds they arrive in, the Sliders tend to get involved in local politics and generally try to make things better. Unless they are on any kind of doomed world, in which case they typically just try to survive until the jump, unless the apocalypse will come before the wormhole, in which case they're destined to stop it.
** They also show a great deal more concern when one of their doubles dies, and have at several points considered staying behind to "fill the gap", before being talked out of it by the others (usually Arturo).
** As the series went along, things became more polarized overall on this subject. Season 4 has Quinn refer to his home Earth (the one the show started at, [[spoiler:not the one he was born on]]) as 'Earth Prime' constantly, and many episodes focus on how "wrong" a world is when X happened instead of Y (like episode 2 of that season, where they encounter a world focused on religion instead of technology. Because all of the science didn't somehow predate their modern technology, it was somehow backwards... all somehow gathered from a glance at a newspaper). This is the same season that introduced a massive cross-reality war between mankind and their Cro-Magnon ancestors.
** Strangely, only two worlds seem to have produced Kromaggs. Both times alongside humans. In one case, the humans ended up kicking the Kromaggs out and, when the Kromaggs obtained sliding tech from an alternate Quinn (the one from the pilot), they start on their interdimensional conquest. The other world has Kromaggs treated like second-class citizens with an underground movement to help them.
* ''Series/DoctorWho'':
** The original series subverts this by having the Doctor traumatized by seeing an alternate Earth being destroyed in the story "[[Recap/DoctorWhoS7E4Inferno Inferno]]". He spends much of the next episode after its destruction in a HeroicBSOD, and the story "[[Recap/DoctorWhoS8E2TheMindOfEvil The Mind of Evil]]" reveals that his memory of seeing a world consumed by fire is his worst fear.
** The episode "[[Recap/DoctorWhoS13E3PyramidsOfMars Pyramids of Mars]]" has Sarah Jane asking the Doctor why they have to risk their lives to save Earth in the past, since they both know Earth is just fine in the present. The Doctor answers her question by bringing her back to the present... and opening the TARDIS door to reveal the wasteland the present will be if they don't stop Sutekh in the past. So they go back and stop Sutekh, and the wasteland present never happens, but the Doctor and Sarah remember it.
** In "[[Recap/DoctorWhoS28E6TheAgeOfSteel The Age of Steel]]", Mickey [[IChooseToStay decides to stay]] in the parallel universe, replacing his counterpart Ricky, instead of going home, because he feels he can help make this world better. (And because his alternate grandmother is still alive.)
** In "[[Recap/DoctorWhoS28E13Doomsday Doomsday]]", Rose is considered to have as much of a "happy ending" as she can without the Doctor -- her mother and father are reunited. Only it's the parallel counterpart of her dad -- the home version is still dead, and the alternate version of her mother is [[AFateWorseThanDeath not around for various reasons]].
*** The season 4 finale confuses things once more by having [[spoiler:Rose]] make a herculean effort to contact the Doctor to warn him of a crisis that threatens ''every'' universe. The Doctor's world isn't so far into crisis as the alternate one, where "the stars are going out". By the end, a reshuffle has taken place: [[spoiler:Mickey's granny is revealed to have died, and he and Rose have concluded their unfinished business; so he returns home. The Doctor's almost-clone goes with Rose and Jackie to the alternate universe.]] Meaning that there's a character in the alternate universe who is -- sort of -- the counterpart of a character in the Doctor's universe, even though he originates from the Doctor's universe himself. Confused?
** Done with an alternate timeline, but still averted in "[[Recap/DoctorWhoS32E10TheGirlWhoWaited The Girl Who Waited]]". Amy is stuck in a faster time stream, and when the Doctor and Rory break into it to rescue her, 36 years have passed leaving her old and bitter. They realize they could yank the younger Amy ahead to their time, but rescuing her would cause Old Amy to cease to exist. Old Amy refuses to help them, being unwilling to "die" and feeling after all this time she ''deserves'' to rescued. She and Rory demand the Doctor find a way to save both versions of Amy, which he does. [[spoiler:Then it turns out that was a lie, only one can be rescued. Old Amy is left behind to be erased (the Doctor considers her to be a worse person than Young Amy), an act that is both heartbreaking and paints the Doctor as unrepentantly manipulative]].
** ''AudioPlay/BigFinishDoctorWho'' has fun with this through the character of Elizabeth Klein. She comes from a timeline inadvertently created when the Doctor left a piece of laser gun technology in Colditz Castle in the middle of World War II, [[AlternateHistoryNaziVictory giving the Nazis the push they needed to win the war.]] The Doctor manages to fix his mistake and correct the course of history...but Klein's now stuck in the main timeline, and sees her timeline as the "correct" version which the Doctor meddled with and altered. [[FromBadToWorse Then she gets hold of a time machine.]] ''The Architects of History'', in particular, raises the question of [[NotSoDifferentRemark what makes the Doctor's meddling different from Klein's:]] a lot of his qualms about killing and collateral damage are shrugged off when it comes to Klein's universe, since it's not "the real one" anyway.
* Deconstructed in ''Series/{{Farscape}}'''s final season episode "[[Recap/FarscapeS04E18Prayer Prayer]]". [[ItMakesSenseInContext Long story short]], John needs some information, and to get it [[spoiler:he has to kill someone]] in an alternate universe where everyone on Moya was combined for some reason. And [[spoiler:that someone is the combined Chiana-Aeryn, Aeryn being his love and Chiana being his little sister-figure. He points his gun, she starts begging for her life in a way that makes it clear she doesn't take it seriously because she can't believe John would do this... a tear rolls down her eye... John puts down the gun, says he can't do it. Which is probably why he brought his arch-nemesis/[[ShadowArchetype shadow]], who predictably grabs John's hand and the gun and executes Chiaeryn.]] He also had reason to believe that they were all going to die within the arn if he hadn't become involved. [[spoiler:This is hopefully why he shrugged off the deaths of two other crewmembers fairly easily.]] Scorpius directly pointed out to John that, officially, the entire alternate universe would ''wink out of existence'' the moment they left it, so anyone who "died" in it would also be ''wiped from existence'' soon enough -- but he still felt bad about it.
* ''Series/HerculesTheLegendaryJourneys'' subverted this trope: Early in the show's run, one episode featured in a throwaway MirrorUniverse where everyone's personalities were swapped: Herc was an evil despot, his {{sidekick}} Iolaus was a cowardly jester, Ares was the God of Love, etc. Many seasons later, after Iolaus had been killed off, Herc wound up with mirror-Iolaus, who has [[CharacterDevelopment developed into an actual character]].
* In ''{{Series/Lexx}}'', they simply abandon their own universe and jump to another after dooming the first one to get consumed by an armed menace...
** Lexx actually has two parallel universes co-existing as equal halves, one "Light" (rigid fascist order) and one "Dark" (chaos - the one our Earth is in). They aren't actually duplicate timelines of each other, so this trope probably shouldn't apply.
* In ''Series/SevenDays'', it is not unusual for most of the main cast to have killed each other before a Backstep.
** There is also an episode where the Sphere glitches, and Frank ends up in a MirrorUniverse, where the US is a dictatorship, everything is written backwards, and all characters are their polar opposites. Naturally, some characters get killed, and Frank gets back to his own reality.
* In ''Series/KamenRiderDecade'', something is causing alternate realities to meld together, so the Kamen Riders entrust Decade with the task of destroying dimensions in order to stop the chaos. While traveling the dimensions (almost all alternate versions of the past ''Kamen Rider'' shows), Decade instead befriends the other Riders and helps them solve potentially world-shaking crises before moving on. In the final arc, the original Riders call Decade to task for not doing his job, and turn on him. [[spoiler:However, it ends up a subversion, as it turns out that destruction ''was'' the correct course of action. Decade's goal was to bridge the worlds, then destroy them to end the merging, at which point those connections would bring everything back as it was and restore balance to the multiverse.]]
* Played with, and ultimately subverted, in ''Series/{{Fringe}}''. At first, it seems that Walter feels this way about his counterpart with the revelation that he [[spoiler:stole his counterpart's son after his own Peter died of a rare disease, but we later find out he intended to send Peter back after curing him; in his grief, he couldn't bring himself to give Peter up]]. Because of our Walter's action, which has also caused fissures in reality and mass casualties in the parallel universe, Walternate felt this way about OUR side, and used his position as Secretary of Defense to prepare for a war with it. The revelation that the universes are slowly destroying each other even gives the parallel universe a legitimate reason to want to destroy the main one. Most of the third season is spent with episodes switching between universes, enabling the audience to gain sympathy for the parallel universe while believing that only one universe can survive, until [[spoiler:the season's final episode shows that the opposite is true - the survival of each universe is ''dependent'' on that of the other, and if one is destroyed the other will ultimately fall apart as well, so they have to work together and learn to trust each other]]. In the fourth season, Walter's dealing with a lot of guilt over the damage he did to the parallel universe. So, thoroughly subverted in the end.
* ''Series/{{Supernatural}}'':
** This occurs in the alternate universe that is ''our'' (or something like it) reality, and in others. It is also inverted in universes in which people live. Averting the ''Titanic'' disaster, for example.
** In the Season Twelve finale, the Winchesters trap Lucifer in an alternate universe, and this is treated as SealedEvilInACan despite the fact that Lucifer is perfectly free to wreak any destruction he chooses on the people of that alternate universe. (And it doesn't even take him that long to find a way back to the main universe). However, this is later subverted in that the Winchesters do everything in their power to save as many people as possible from that dimension. Alt!Charlie even makes a point that she's not just some ReplacementGoldfish for their own Charlie--her priorities are in her own dimension.
** It turns out that God created the multiverse in the first place because [[spoiler:he's a writer. Writers tend to go through lots of drafts before finishing their stories, don't they? He's already killed the Winchesters many, many times over in various dramatic and contrived ways, then just moves on to the next world. Eventually he deems those alternate universes to be a distraction to his goal of herding Prime Sam and Dean, so he proceeds to [[OmnicidalManiac obliterate them one by one]].]]
* ''Series/{{Community}}'' episode [[Recap/CommunityS3E04RemedialChaosTheory Remedial Chaos Theory]] explores this. Jeff rolls a die to decide who gets pizza and creates six different timelines, each one of them starting events that develop depending on who leaves the group. In the main timeline, Abed catches the die, but in the timeline where [[TheHeart Troy]] leaves, things go very bad, very quickly. Pierce gets shot in the leg and dies, Annie gets locked away in a mental institution, Jeff loses an arm, Troy destroys his larynx, Shirley falls OffTheWagon and [[ArsonMurderAndJaywalking Britta...dyes her hair blue]]. Abed and Troy decide that since this is obviously the darkest timeline, they should commit to being evil and find way to the main timeline, kill their alternate selves and reclaim their lives. This becomes a plot point later in the season, [[spoiler:as Abed starts seeing Evil!Abed in times of great insecurity, culminating in Evil!Abed taking over Abed's body in the season finale.]] Of course, since ''Series/{{Community}}'' is not a sci-fi show, any or all of this [[MaybeMagicMaybeMundane may just be Abed's imagination.]]
* In an episode of ''Series/EarthFinalConflict'', Liam and Augur have a shuttle accident and find themselves in an alternate universe where the Taelons are invading Earth. Human civilization has also taken a different track, eschewing large settlements and preferring to live in harmony with nature with trade centers being the only permanent places with structures. Nevertheless, they are better prepared to fight the Taelons due to millennia of conflict amongst themselves (they have energy weapons, for example). A number of LaResistance members in this 'verse are killed (including Sandoval's double Jason, who is the leader), but Liam and Augur (along with Jason's girlfriend) manage to escape. Only a few episodes mention the other universe, but it is quickly forgotten.
* ''Series/{{Charmed|1998}}'' introduced an evil counterpart to the main universe so whenever good succeeds in "our" world, evil succeeds in the other. Things have to be that way so the sisters can't help the other world but they continue to do good in our world knowing that means that they are doing evil to alternate people in the other.
* Canadian scifi series ''Series/{{Continuum}}'' plays this kind of loose, given that most of the characters within it don't seem to grasp their own time travel rules. Characters in the earlier seasons openly wonder if their "future" selves and families will continue to exist, or if even the ripple-effects of their mere presence in the past have already altered the timeline so drastically that their own parents will never meet. The mysterious time-traveling conspiracy from even farther in the future - known as "The Freelancers" - give a an explanation in Season 2: ''every'' time-travel event creates a branching timeline, co-existing alongside the original. When Cameron and the [=Liber8=] terrorists traveled back in time, they ''created'' Timeline-2. This is explicitly why they are able to avoid grandfather paradoxes: Kellog's own grandmother was killed in Season 1, but he didn't wink out of existence. This was because it wasn't really ''his'' grandmother from Timeline-1, but an exact duplicate made along with Timeline-2. Thus it is ''impossible'' for [=Liber8=] to prevent the rise of the corporate-ocracy in Timeline-1: all they can do is prevent it from rising in Timeline-2...which wouldn't even have existed in the first place if they hadn't traveled in time. It is also difficult to impossible for Cameron to return to her own son in Timeline-1's 2077.
** This isn't entirely perfect, though, as killing the guy who invented the time machine you used to get there ''will'' create a time paradox. In the Season 3 premiere, Alec from Timeline-2 travels back in time a week to save his girlfriend's life, creating Timeline-3. If the Freelancers are correct, he didn't "save" the original, he simply created an exact duplicate...along with a duplicate of ''himself'' from one week in the past, who proceeds to become his rival for an entire season (both debating which has more right to claim their identity). Because Alec goes on to invent time travel, removing himself from Timeline-2 is an unsustainable paradox - his younger self can't be "killed" (removed from the timeline) with a time travel machine he hadn't even invented yet. We actually see Timeline-2 and Timeline-3 briefly coexisting, before Timeline-2 ''collapses'' and everyone in it dies.
** ...then it turns out that the new Timeline-3 future is even worse than Timeline-1: [=Liber8=] didn't succeed in stopping the corporations from taking over world government, only weakening them just enough that the fighting stalemated, eventually degenerating into multi-faction anarchy, so that the alternate 2030's are a hellhole of constant warfare...in which Kellog is a major faction leader. Basically, anyone who wants to change their own timeline cannot, but if you just want to create a new timeline/universe where you can live like a king by abusing your knowledge of the (alternate but similar) future timeline, that is possible - which suits Kellog just fine.
** The finale ''apparently'' created a final, Timeline-4 in which things worked out - though the show was forced to end quickly with a truncated fourth season, and the showrunners insisted that he planned out a longer storyarc than that.
* A variation appears in the ''Series/TheOrville'' novella [[note]]origianlly written as an episode but derailed by COVID-related production problems with overseas shooting[[/note]] "[[Recap/TheOrvilleNovellaSympathyForTheDevil Sympathy For the Devil]]". [[spoiler:An infant is left in the care of a simulator for thirty years, and ends up becoming an SS officer in charge of a death camp within the simulated environment, When he is brought into the real world of the 25th century, the crew wrestles with the issue of his moral culpability for evil acts that didn't hurt any ''real'' people but have shaped him into a Nazi true believer]].

[[folder:Podcasts]]
* Joked about by Hannah in the Gemini Arc of ''Podcast/{{Sequinox}}'', which features the Sequinox team getting thrown into various multiple alternate worlds. Early on she declares that all the worlds they're going to are "fake" simply to avoid thinking too hard about it. Ultimately subverted, however, as the girls do start taking steps to not make things difficult when their alternates are brought back into their own worlds and actively ensure that their allies understand the situation in places where their lack of knowledge has major impacts upon the world.

[[folder:Tabletop Games]]
* ''TabletopGame/{{GURPS}}'':
** The setting ''TabletopGame/InfiniteWorlds'' notes that neither Infinity nor Centrum quite view people from other worldlines as real people. Among other things, it notes that some filmmakers have taken to filming real battles on other worldlines with thousands of people dying to use as footage in their historical epics.
** The Inertial Brake device in ''Warehouse 23'' is described as working by dumping the ship's inertia into an alternate timeline, where it will likely cause some localized disaster.
* Supplemental material for ''TabletopGame/HcSvntDracones'' reveals that Transcendent Technology Industries conducted research with this principle, setting up a group of observers whenever they were going to do something particularly dangerous. If the guys didn't change, great, go on forward. If the guys suddenly became disheveled, they came from an alternate universe that went a few weeks into the future and all tests would be discontinued. Of course, the brass claimed that it was just a 'save point time travel' situation... [[spoiler:and then it turned out all their research consisted of picking an EldritchAbomination's brain and that said creature was actually a [[TheConstant Universal Constant]] [[ItCanThink that learned every time they did so.]] They cut that path of research off fast.]]
* ''TabletopGame/SentinelsOfTheMultiverse'':
** Played for laughs in the [=OblivAeon=] Letters Page episode, where Christopher and Adam spend several minutes establishing the existence of a {{Telenovela}} universe, only for [=OblivAeon=] to wipe it out of existence.
** Played much more seriously with the Iron Legacy timeline which is destroyed by La Comodora in the leadup to [=OblivAeon=]. At that point it was considered a mercy to destroy the timeline since basically everything was destroyed and almost everyone was dead and all that's left are the Wraith and Iron Legacy, fighting against the backdrop of a broken city. La Comodora even says that erasing a timeline is not something to be considered lightly.

[[folder:Toys]]
* ''Toys/{{Bionicle}}'' does this when Takanuva ends up in an AlternateUniverse rules by a corrupt empress. That serial featured more on-screen deaths than the rest of the canon ''combined'' at the time of writing. It's a partial subversion, since Takanuva is genuinely shocked by some of the things he sees, such as [[spoiler:his younger self getting impaled by iron spikes]], and he tries to help the people in that universe as well as reaching his own goals of getting home, but after he gets out of there ([[spoiler:[[PortalCut and accidentally cuts the empress in half by way of a closing interdimensional portal]]]]), he takes only a few moments to wonder about the fate of that universe before continuing on with his quest.
** Played straight when a bunch of Takanuvas are taken from their original universes, forcibly turned evil, and then [[spoiler:get smashed to bits by one of the good guys with a warhammer]].

* ''VideoGame/LEGOStarWars''. "In an infinite universe, all things are possible..." Though it's really just the one parallel universe where you must [[DieChairDie blow everything up]] to collect a million Lego studs -- despite the fact that you're using Star Wars Lego figures on a generic suburban Lego Town...

[[folder:Visual Novels]]
* ''VisualNovel/MuvLuv'': {{Averted|Trope}} where Takeru cares about his friends no matter what universe they're in.
* Comes up across the ''VisualNovel/ZeroEscape'' series, which is confirmed to run on the [[MultipleChoiceFuture Many-Worlds Theory]] - there are countless universes out there, each being created as one of the results of any decision. Not all of them are [[BadFuture pleasant.]]
** ''VisualNovel/NineHoursNinePersonsNineDoors'': Zero/[[spoiler:Akane Kurashiki]] is more than willing to screw over numerous people across several different continuities until they reach the desired outcome: [[spoiler:a timeline where Junpei successfully accesses the morphogenetic field to send Akane's younger self the information she needs in order to escape from the incinerator puzzle, which [[StableTimeLoop she only escaped from using the information he sent back to her]].]]
** ''VisualNovel/VirtuesLastReward'': [[spoiler:Sigma and Phi]] are able to project their consciousnesses across different timelines, swapping with their counterparts from those worlds. This allows them to escape the timelines where [[spoiler:they and the other Nonary Game participants end up trapped forever]] or [[spoiler:succumb to [[ThePlague Radical-6]]]], but it's also proven that those worlds still exist even after they leave. [[spoiler:It's revealed that the AB Project's goal of using this to prevent the outbreak of Radical-6 from ever happening, even if Dr. Klim is successful, means the players of this game will still be stuck in their current BadFuture.]]
** ''VisualNovel/ZeroTimeDilemma'' continues the trend with multiple timelines that end badly. And it turns out that all the timelines that aren't [[spoiler:the one that leads to ''Virtue's Last Reward'' or the final ending are even worse than ''VLR'''s timeline, since a nuclear war will end up wiping out all of humanity, whereas Radical-6 "only" wipes out about 70% of it.]] But it's taken to an even greater height as we learn that when anyone [=SHIFTs=], their consciousness trades places with the consciousness that was in that body up to that point in time. So not only are the universes they are leaving behind screwed, but they are screwing over an alternate version of themselves in the process to retain their memories. This becomes especially relevant [[spoiler:in the ending. All 9 players have learned the truth of what they need to do to save the world. Only problem is that they are locked in the bunker which is about to explode with no physical way out. The only way they can escape with their knowledge to save the world is to SHIFT over to the versions of themselves that were freed before the game even began. They know full well that doing this will condemn the alternate version of themselves to die without ever knowing why. Though you can choose not to, you ultimately must to get the final ending.]]
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[[folder:Webcomics]]

* {{Inverted|Trope}} in ''WesternAnimation/RickAndMorty'': in "[[Recap/RickAndMortyS1E6RickPotionNumber9 Rick Potion #9]]", Rick and Morty inadvertently cause the end of the world and the former simply takes them to an alternate universe where they both died and take their counterparts' place, making this an example of an Expendable ''Main'' Universe. Morty is clearly traumatized by the notion that his friends and family are all doomed and he will spend the rest of his life with identical strangers. Given how nonchalant Rick is about this, it's quite clear that he considers ''[[StrawNihilist every]]'' universe expendable. "[[Recap/RickAndMortyS5E10RickamuraiJack Rickmurai Jack]]" reveals that the main Rick has pulled this exact trick at least once before, and he's from a different dimension than the Morty that the show is following (in Rick's original reality, [[spoiler:his family was killed]], which explains a lot about his nihilistic attitude). In "[[Recap/RickAndMortyS6E1Solaricks Solaricks]]", [[spoiler:the entire family has to go to another alternate dimension after the Jerry from the Jerryboree returns and gets the Earth destroyed]].

* {{Inverted|Trope}} in ''WesternAnimation/RickAndMorty'': in "[[Recap/RickAndMortyS1E6RickPotionNumber9 Rick Potion #9]]", Rick and Morty inadvertently cause the end of the world and the former simply takes them to an alternate universe where they both died and take their counterparts' place, making this an example of an Expendable ''Main'' Universe. Morty is clearly traumatized by the notion that his friends and family are all doomed and he will spend the rest of his life with identical strangers. Given how nonchalant Rick is about this, it's quite clear that he considers ''every'' universe expendable. "[[Recap/RickAndMortyS5E10RickamuraiJack Rickmurai Jack]]" reveals that the main Rick has pulled this exact trick at least once before, and he's from a different dimension than the Morty that the show is following (in Rick's original reality, [[spoiler:his family was killed]], which explains a lot about his nihilistic attitude). In "[[Recap/RickAndMortyS6E1Solaricks Solaricks]]", [[spoiler:the entire family has to go to another alternate dimension after the Jerry from the Jerryboree returns and gets the Earth destroyed]].

* Played with, and ultimately subverted, in ''Series/{{Fringe}}''. At first, it seems that Walter feels this way about his counterpart when he [[spoiler:steals his counterpart's son after his own Peter dies of a rare disease, but we later find out he intended to sent Peter back after curing him]]. Because of our Walter's action, which has also caused fissures in reality and mass casualties in the parallel universe, Walternate felt this way about OUR side, and used his position as Secretary of Defense to prepare for a war with it. The revelation that the universes are slowly destroying each other even gives the parallel universe a legitimate reason to want to destroy the main one. Most of the third season is spent with episodes switching between universes, enabling the audience to gain sympathy for the parallel universe while believing that only one universe can survive, until [[spoiler:the season's final episode shows that the opposite is true - the survival of each universe is ''dependent'' on that of the other, and if one is destroyed the other will ultimately fall apart as well, so they have to work together and learn to trust each other]]. In the fourth season, Walter's dealing with a lot of guilt over the damage he did to the parallel universe. So, thoroughly subverted in the end.

** ''VideoGame/FireEmblemAwakening'' averts this in a big way. [[spoiler:Since a large amount of characters are from alternate futures where the heroes have had a lot less luck, in a Fire Emblem game especially, seeing any character as expendable can doom you down the road. And then there's how the characters, in-game, feel about the future characters. All of the future characters are children of the 'present' heroes. There's even a DLC chapter where the heroes from the present work to save one BadFuture timeline.]]

** Played with in "[[Recap/FuturamaS4E15TheFarnsworthParabox The Farnsworth Barabox]]". When the Planet Express crew arrives in an alternate, {{palette swap}}ped universe, they argue with their counterparts over whose universe is Universe A. ("Why do we have to be 'B'?" "This place kinda feels like a B...") Eventually they decide on the names Universe A and Universe 1. Also, both Benders genuinely care about their perpendicular universe counterparts, because if there's one thing Bender loves, it's Bender.

** Another example in ''Ultra Sun and Ultra Moon'' are the universes where the members of Team Rainbow Rocket. [[spoiler:Each of the members come from universes where their respective game protagonists weren't there to stop them and [[TheBadGuyWins they won]]. Their respective regions and realities would range from becoming {{Crapsack World}}s to [[ApocalypseHow simply ceasing to exist]].]]

-->-- ''WesternAnimation/RickAndMorty'', "Rick Potion #9"

[[folder:Web Comics]]

** Subverted with [[spoiler:the Farmworld alternate timeline. When we first see it in the episodes "Finn the Human" and "Jake the Dog", the Lich manages to bring about another nuclear apocalypse and that dimension's Finn goes mad thanks to Simon's crown. In "Crossover", Prismo calls on Finn and Jake to kill that dimension's Lich, giving Farmworld a BelatedHappyEnding in the process.]]

** Played with in one episode. When the Planet Express crew arrives in an alternate, {{palette swap}}ped universe, they argue with their counterparts over whose universe is Universe A. ("Why do we have to be 'B'?" "This place kinda feels like a B...") Eventually they decide on the names Universe A and Universe 1. Also both Benders genuinely care about their perpendicular universe counterparts, because if there's one thing Bender loves, it's Bender.
-->'''Narrator:''' Meanwhile, in Universe A, Hermes A heads towards the sun. ...A.
** In ''Bender's Big Score'', Professor Farnsworth and the Harlem Globetrotters discover a law of physics detailing how the universe protects itself from {{time paradox}}es: It arbitrarily kills any clones created via TimeTravel. This happens several times over the course of the film; some clones are mourned more than others.
** In "The Late Phillip J. Fry" a time machine that can only go forward in time takes Fry, Bender, and the Professor further and further into the future, until the universe they knew dies out and a new universe, completely identical to the old one, comes into being. They consider this a completely acceptable substitute for the real thing. This is actually an inversion, since it portrays the original universe as expendable and the original Leela was shown missing Fry and being miserable for the rest of her life, but Fry isn't particularly concerned because he just continues off with the new identical Leela in the new universe. It's also partially played straight in the Fry, Bender, and the Professor kill their counterparts upon arriving in the new universe and aren't particularly concerned (though given the previously established paradox rule that duplicates cannot co-exist, this may have been inevitable).
** That being said, it wasn't entirely clear if the new universe that restarts after the end of the last one is actually "new", or a reboot of the original copying over itself. So it isn't clear if our "original" Leela actually died alone missing Fry, or if that future never occurred, because original Fry traveled so far into the future that he went full circle and came back to the present.
** There is also an episode where the crew takes Fry on a tour of the Universe and its tourist attractions. One is a scenic outlook to a parallel universe. The difference? Everyone in the parallel universe is wearing cowboy hats. When Fry asks about there being an infinite numbers of these parallels, he is told that there is in fact only one parallel to their own. His response is that's probably enough. It's also why the alternate universes mentioned above are referred to as "perpendicular" rather than parallel in the DVDCommentary.

* In the underrated and at-times quite creepy ''WesternAnimation/PeterPanAndThePirates'', one episode has Peter and the gang entering an alternate universe where copies of Peter Pan, Wendy and the Lost Boys are slaves, toiling endlessly to prevent the Corc (their version of the crocodile that Captain Hook and everyone else are afraid of) from awakening. Peter Pan et al have an adventure in this alternate universe, but are unable to save these copies of themselves from their lifetime of misery and slavery. The copies help the originals escape, and that's it.
* {{Inverted|Trope}} in ''WesternAnimation/RickAndMorty'': in "Rick Potion No. 9", Rick and Morty inadvertently cause the end of the world and the former simply takes them to an alternate universe where they both died and take their counterparts' place, making this an example of an Expendable ''Main'' Universe. Morty is clearly traumatized by the notion that his friends and family are all doomed and he will spend the rest of his life with identical strangers. Given how nonchalant Rick is about this, it's quite clear that he considers ''every'' universe expendable. ''Rickmurai Jack'' reveals that the main Rick has pulled this exact trick at least once before, and he's from a different dimension than the Morty that the show is following (in Rick's original reality, [[spoiler:his family was killed]], which explains a lot about his nihilistic attitude). In ''Solaricks'' [[spoiler:the entire family has to go to another alternate dimension after the Jerry from the Jerryboree returns and gets the Earth destroyed.]]

*** In the episode "Running To Stand Still" Earth-2 Harrison Wells sends hundreds of bombs through a wormhole to an alternate dimension. No one seems to consider the bombs might be raining down on a bunch of their alternate selves.

** Much like in the story it's based off of, ''[[Series/CrisisOnInfiniteEarths2019 Crisis on Infinite Earths]]'' wipes out many worlds based off other live action adaptations of DC Comics to raise the stakes. Among the victims include [[Film/Batman1989 Tim Burton's Batman]], ''Series/{{Titans}}'', [[Series/CrisisOnEarthX Earth-X]], [[Series/Batman1966 the 60s Batman series]], and ''Series/BirdsOfPrey''. Tie-in comics also add the ComicBook/New52, [[Series/WonderWoman1975 the 70s Wonder Woman series]], and the WesternAnimation/SupermanTheatricalCartoons by Creator/FleischerStudios.

** Played reasonably straight in the episode "The Wish". By the end of the episode, Giles and Oz are the only main characters left alive; then Giles manages to hit the ResetButton and restore the original universe, accepting the erasure of his own world because the other reality ''has'' to be better.
** In the follow-up episode "Doppelgangland", the heroes have no problem with returning Vampire Willow to her own universe rather than staking her, even though she's killed people there in the past and fully intends to continue killing people once she gets back, apparently it's okay because she's not hurting anyone from our Buffyverse and Willow thinks she's kind of cool. She ended up being staked by Wishverse Oz almost immediately after returning to her universe, but the heroes had no way of knowing that would happen.

** Almost every ''Star Trek'' series had at least one episode where a NegativeSpaceWedgie produces a horror world, and everybody dies fixing the problem, but then our world [[SnapBack Snaps Back]], so all is well. (For instance, the ''Series/StarTrekTheNextGeneration'' episode "Yesterday's Enterprise" and the ''Series/StarTrekVoyager'' episode "Year of Hell".)
** A downplayed example, where the death of an alternate is treated as acceptable but still tragic, is the ''Series/StarTrekTheNextGeneration'' episode "Parallels". A NegativeSpaceWedgie rips a hole in time, and five billion plus Starships Enterprise need to get back to their home dimensions. This takes place in a second (for lack of a better term) universe where Riker is captain, and he leads the effort to fix the hole. Then a third Riker tries to stop him -- the third Riker is crazed, from a horrible universe where the Borg have conquered the galaxy, and doesn't want to go back. The second Riker has his ''Enterprise'' fire on the third, intending to dissuade it, but the travails of the third ship had already done such a number that even a light shot blew it apart. Riker wasn't happy. The TechnoBabble that ended the episode was effectively a ResetButton, and while Worf retained his memory of it, it effectively didn't happen.

** In ''Series/StarTrekDeepSpaceNine'', there is an episode where Time Travel Disease keeps sending O'Brien forward in time to see himself die. (See: O'Brien Must Suffer). He goes to great lengths to save himself each time until the disease kills him, at which point Alternate Timeline O'Brien goes back in his place to save the station. In a subversion of the main trope, Alternate O'Brien feels very bad about Regular O'Brien's death.
** Another ''[=DS9=]'' episode seriously looks at this trope, where the ''Defiant'' crew learns that, thanks to the TimeyWimeyBall, they'll soon crash-land hundreds of years in the past on an isolated planet. While their descendants will form a thriving colony of 8,000 people, the crew themselves will inevitably die on the planet (save for the long-lived Odo) and never see their family and friends back home, and Kira will die shortly after the crash. Sisko really doesn't want to strand his crew, and knows they could easily avoid the accident now, but that would {{Retgone}} the entire colony, effectively killing thousands of people. Ultimately, the crew reluctantly decides to subvert the trope at their own expense and go through with the crash -- only for the older version of Odo to forcibly make the ship escape and erase the entire colony, all to prevent Kira from dying. Kira herself is ''horrified'' when she learns about this, especially as she'd made peace with dying for the sake of preserving lives.

** Downplayed in the ''Series/StarTrekTheOriginalSeries'' episode "Mirror, Mirror". Kirk cares enough about the denizens of the Mirror Universe to try and convince the crew of the Mirror!Enterprise, and especially Mirror!Spock, to give up their violent and authoritarian ways, but it's still treated as less important than returning the trapped crew members from his home universe.

** In the alternate universe seen in "There But For the Grace of God", the Goa'uld actually succeed in conquering Earth and killing the counterparts of SG-1 (except for Teal'c, who never defected from Apophis in this universe). (Teal'c got to die offscreen when the base was programmed to [[SelfDestructMechanism self destruct]].)
** As an exception, "Point of View" had "our" team travel to an AlternateUniverse to help stop the Goa'uld invasion of Earth (although they still did it only after they found out that the alternate Samantha Carter couldn't stay in their universe). Although, oddly, this episode, while not following the trope, does explicitly state it. Teal'c (rather nonchalantly) kills his alternate, and when he's questioned about it by his (incredibly freaked out) teammates, he doesn't hesitate to matter-of-factly state "ours is the only reality of consequence". While this seems unusually callous of Teal'c, FridgeBrilliance may be relevant: he's TheAtoner, so he would be particularly willing to kill a version of himself who was still guilty of what the "real" Teal'c was trying to atone for.
** The episode "2010" sees the SG-1 of the year 2010 (ten years in the future of the time the episode aired) come up with a plan to erase their timeline, despite having defeated the Goa'uld with the aid of their allies the Aschen, because they've learned that the Aschen are sterilizing ninety percent of Earth's population to make humanity their slaves, with the Tau'ri lacking the resources to oppose the Aschen on their own and concluding that the only way to stop them is to prevent this alliance from ever being formed in the first place.
** "Ripple Effect":

** In the season 10 episode "The Road Not Taken", Carter and her counterpart in another universe are experimenting with an Ancient device simultaneously. Something goes wrong and our Sam is transported to the other side. The other Sam wasn't so lucky. No one from the other side seems too upset about this, whereas our SG-1 is extremely worried for the duration of our Sam's absence.

** Subverted in "[=McKay=] and Mrs Miller"; the techies have no qualms doing great damage to an alternate reality until they find out that life also exists in it (a chance that was considered astronomically small).
** Subverted in "The Daedalus Variations"; the team is stuck on an alternate reality ''Daedalus'' which is jumping through different realities. In one reality, an unknown alien race starts attacking Atlantis. Sheppard insists on intervening, convinced that this reality's Atlantis are still the "good guys". It leads to the aliens attacking them as well, but the alternate Atlantis helps, so it works out. Played straight with Ronon however. Teyla at one point wonders if her dead counterpart had a child as well only for Ronon to say worrying about every single reality's Teyla and her child is pointless.
** The penultimate episode, "Vegas", is [[AlternateRealityEpisode set in a separate alternate universe]] where Sheppard is a CSI-style detective in Las Vegas hunting down a rogue Wraith that somehow got to Earth. However, before the Wraith dies, it transmits a signal throughout the Multiverse shouting Earth's location. The Alternate!Woolsey's response to this is that it's pointless to worry about saving every possible universe and is sufficiently pleased to have prevented the invasion in his own. Unfortunately for the primary versions of the cast, the message makes it to their universe, setting up the finale.

* In ''Series/DoctorWho'':
** Mickey [[IChooseToStay decides to stay]] in the parallel universe, replacing his counterpart Ricky, instead of going home, because he feels he can help make this world better. (And because his alt!grandmother is still alive.)
** And Rose is considered to have as much of a "happy ending" as she can without the Doctor -- her mother and father are reunited. Only it's the parallel counterpart of her dad -- the home version is still dead, and the alternate version of her mother is [[AFateWorseThanDeath not around for various reasons]].
*** The season 4 finale confuses things once more by having [[spoiler:Rose]] make a herculean effort to contact the Doctor to warn him of a crisis that threatens ''every'' universe. The Doctor's world isn't so far into crisis as the alternate one, where "the stars are going out". By the end, a reshuffle has taken place: [[spoiler:Mickey's granny is revealed to have died, and he and Rose have concluded their unfinished business; so he returns home. The Doctor's almost-clone goes with Rose and Jackie to the alternate universe.]] Meaning that there's a character in the alternate universe who is - sort of - the counterpart of a character in the Doctor's universe, even though he originates from the Doctor's universe himself. Confused?
** The original series also subverts this by having the Doctor traumatized by seeing an alternate Earth being destroyed in the story "Inferno". He spends much of the next episode after its destruction in a HeroicBSOD, and the story "The Mind of Evil" reveals that his memory of seeing a world consumed by fire is his worst fear.
** Done with an alternate timeline, but still averted in "The Girl Who Waited". Amy is stuck in a faster time stream, and when the Doctor and Rory break into it to rescue her, 36 years have passed leaving her old and bitter. They realize they could yank the younger Amy ahead to their time, but rescuing her would cause Old!Amy to cease to exist. Old!Amy refuses to help them, being unwilling to "die" and feeling after all this time she ''deserves'' to rescued. She and Rory demand the Doctor find a way to save both versions of Amy, which he does. [[spoiler:Then it turns out that was a lie, only one can be rescued. Old!Amy is left behind to be erased (the Doctor considers her to be a worse person than Young!Amy), an act that is both heartbreaking and paints the Doctor as unrepentantly manipulative]].
** The Original Series episode "Pyramids of Mars" has Sarah Jane asking the Doctor why they have to risk their lives to save Earth in the past, since they both know Earth is just fine in the present. The Doctor answers her question by bringing her back to the present... and opening the TARDIS door to reveal the wasteland the present will be if they don't stop Sutekh in the past. So they go back and stop Sutekh, and the wasteland present never happens, but the Doctor and Sarah remember it.

* Deconstructed in ''Series/{{Farscape}}'''s final season episode "Prayer". [[ItMakesSenseInContext Long story short]], John needs some information, and to get it [[spoiler:he has to kill someone]] in an alternate universe where everyone on Moya was combined for some reason. And [[spoiler:that someone is the combined Chiana-Aeryn, Aeryn being his love and Chiana being his little sister-figure. He points his gun, she starts begging for her life in a way that makes it clear she doesn't take it seriously because she can't believe John would do this...a tear rolls down her eye...John puts down the gun, says he can't do it. Which is probably why he brought his arch-nemesis/[[ShadowArchetype shadow]], who predictably grabs John's hand and the gun and executes Chiaeryn.]] He also had reason to believe that they were all going to die within the arn if he hadn't become involved. [[spoiler:This is hopefully why he shrugged off the deaths of two other crewmembers fairly easily.]] Scorpius directly pointed out to John that, officially, the entire alternate universe would ''wink out of existence'' the moment they left it, so anyone who "died" in it would also be ''wiped from existence'' soon enough - but he still felt bad about it.

** After [[spoiler:Prismo]] dies, it's revealed that he set up a TimeTravel-based gambit to reverse this that involves [[ItMakesSenseInContext an alternate Jake falling into an eternal sleep]] and [[ItMakesJustAsMuchSenseInContext an alternate Finn getting turned into a sword]]. None of the three see any problem with this, and Jake might even be jealous of his parallel's amazingly comfortable sleeping arrangements. A later episode even shows ''the Finn turned into the sword'', who can [[TalkingWeapon still talk]], has no problem with this.

* ''Wiki/SCPFoundation'':

* After [[spoiler:Prismo]] dies in ''WesternAnimation/AdventureTime'', it's revealed that he set up a TimeTravel-based gambit to reverse this that involves [[ItMakesSenseInContext an alternate Jake falling into an eternal sleep]] and [[ItMakesJustAsMuchSenseInContext an alternate Finn getting turned into a sword]]. None of the three see any problem with this, and Jake might even be jealous of his parallel's amazingly comfortable sleeping arrangements. A later episode even shows ''the Finn turned into the sword'', who can [[TalkingWeapon still talk]], has no problem with this ([[MaybeMagicMaybeMundane assuming that's not just "prime" Finn talking to himself]]).

** ''Film/SpiderManNoWayHome'' [[spoiler:subverts this ''and'' combines it with AlwaysSaveTheVillain]]. Upon learning from Strange that [[spoiler:all the villains pulled into the Marvelverse are doomed to die]] back in their own worlds, [[spoiler:[=MCU=] Peter Parker stops Strange from sending them back before he can alter the fates of the rogues from the Franchise/SpiderManTheatricalFilms and Franchise/TheAmazingSpiderMan universes]].

** Season 3 introduced ''yet another'' possible ugly future which contains, among other things [[spoiler:Hiro's (apparent) death at the hands of his best friend Ando, Claire killing Peter, and a redeemed Sylar cratering Costa Verde (and killing Matt's future wife in the process) when his own son is killed and he loses control of Ted's powers. Also the mass proliferation of super-people has the Earth primed to ''EXPLODE'']], But none of it has happened ''yet''. Neither will it happen, since that future is dead as well. [[spoiler: We seem to be locked on target for Five Years Gone, however...]]

** Subverted in "The Daedalus Variations"; the team is stuck on an alternate reality ''Daedalus'' which is jumping through different realities. In one reality, an unknown alien race starts attacking Atlantis. Sheppard insists on intervening convinced that this reality's Atlantis are still the "good guys". It leads to the aliens attacking them as well, but the alternate Atlantis helps, so it works out. Played straight with Ronon however. Teyla at one point wonders if her dead counterpart had a child as well only for Ronon to say worrying about every single reality's Teyla and her child is pointless.

* Deconstructed in ''Series/{{Farscape}}'''s final season episode "Prayer". [[ItMakesSenseInContext Long story short]], John needs some information, and to get it [[spoiler: he has to kill someone]] in an alternate universe where everyone on Moya was combined for some reason. And [[spoiler: that someone is the combined Chiana-Aeryn, Aeryn being his love and Chiana being his little sister-figure. He points his gun, she starts begging for her life in a way that makes it clear she doesn't take it seriously because she can't believe John would do this...a tear rolls down her eye...John puts down the gun, says he can't do it. Which is probably why he brought his arch-nemesis/[[ShadowArchetype shadow]], who predictably grabs John's hand and the gun and executes Chiaeryn.]] He also had reason to believe that they were all going to die within the arn if he hadn't become involved. [[spoiler: This is hopefully why he shrugged off the deaths of two other crewmembers fairly easily.]] Scorpius directly pointed out to John that, officially, the entire alternate universe would ''wink out of existence'' the moment they left it, so anyone who "died" in it would also be ''wiped from existence'' soon enough - but he still felt bad about it.

* ''Series/{{Community}}'' episode [[Recap/CommunityS3E04RemedialChaosTheory Remedial Chaos Theory]] explores this. Jeff rolls a die to decide who gets pizza and creates six different timelines, each one of them starting events that develop depending on who leaves the group. In the main timeline, Abed catches the die, but in the timeline where [[TheHeart Troy]] leaves, things go very bad, very quickly. Pierce gets shot in the leg and dies, Annie gets locked away in a mental institution, Jeff loses an arm, Troy destroys his larynx, Shirley falls OffTheWagon and [[ArsonMurderAndJaywalking Britta...dyes her hair blue]]. Abed and Troy decide that since this is obviously the darkest timeline, they should commit to being evil and find way to the main timeline, kill their alternate selves and reclaim their lives. This becomes a plot point later in the season, [[spoiler: as Abed starts seeing Evil!Abed in times of great insecurity, culminating in Evil!Abed taking over Abed's body in the season finale.]] Of course, since ''Series/{{Community}}'' is not a sci-fi show, any or all of this [[MaybeMagicMaybeMundane may just be Abed's imagination.]]

* A variation appears in the ''Series/TheOrville'' novella [[note]]origianlly written as an episode but derailed by COVID-related production problems with overseas shooting[[/note]] "[[Recap/TheOrvilleNovellaSympathyForTheDevil Sympathy For the Devil]]". [[spoiler: An infant is left in the care of a simulator for thirty years, and ends up becoming an SS officer in charge of a death camp within the simulated environment, When he is brought into the real world of the 25th century, the crew wrestles with the issue of his moral culpability for evil acts that didn't hurt any ''real'' people but have shaped him into a Nazi true believer]].

* ''Toys/{{Bionicle}}'' does this when Takanuva ends up in an AlternateUniverse rules by a corrupt empress. That serial featured more on-screen deaths than the rest of the canon ''combined'' at the time of writing. It's a partial subversion, since Takanuva is genuinely shocked by some of the things he sees, such as [[spoiler: his younger self getting impaled by iron spikes]], and he tries to help the people in that universe as well as reaching his own goals of getting home, but after he gets out of there ([[spoiler:[[PortalCut and accidentally cuts the empress in half by way of a closing interdimensional portal]]]]), he takes only a few moments to wonder about the fate of that universe before continuing on with his quest.

* In ''VideoGame/BackToTheFutureTheGame'' this is brought up as a plot point. Thanks to things going haywire in the past, Marty winds up in [[spoiler: a version of 1985 where Hill Valley is ruled by Edna Strickland, and has to recruit Doc (who had fallen in love with her) to go back in time and set things right. However this Doc learns that in the normal 1985, Edna is sad and lonely, and aborts the mission to try and stop Marty from succeeding]].

** Averted in the ''Burial at Sea'' DLC, which is centered around Elizabeth [[spoiler: going to other universes and trying to right the wrongs by the Comstocks of every reality and reuniting the Bookers with their daughters]].

** Defied in the Delta Episode of ''[[VideoGame/PokemonRubyAndSapphire Pokémon Omega Ruby and Alpha Sapphire]]''. [[spoiler: The original plan to stop a meteor from destroying the world is using an interdimensional teleportation device to send it to an alternate reality (implied to be that of the original Ruby and Sapphire), but Zinnia destroys the mechanism needed to operate it, noting that sending it to an alternate reality would only wreak havoc on that reality's version of the world instead and they wouldn't have the technology to do the same.]]
** Played straight in ''VideoGame/PokemonUltraSunAndUltraMoon''. [[spoiler: One of the Ultra Spaces you can visit is a version of Hau'oli City that has been devastated by a nuclear meltdown. You have the ability to catch Guzzlord, who are native to this reality and are dwindling in number, but there's no way to bring the lone resident human back to your universe.]]
** Another example in ''Ultra Sun and Ultra Moon'' are the universes where the members of Team Rainbow Rocket. [[spoiler: Each of the members come from universes where their respective game protagonists weren't there to stop them and [[TheBadGuyWins they won]]. Their respective regions and realities would range from becoming {{Crapsack World}}s to [[ApocalypseHow simply ceasing to exist]].]]

** ''VisualNovel/NineHoursNinePersonsNineDoors'': Zero/[[spoiler: Akane Kurashiki]] is more than willing to screw over numerous people across several different continuities until they reach the desired outcome: [[spoiler: a timeline where Junpei successfully accesses the morphogenetic field to send Akane's younger self the information she needs in order to escape from the incinerator puzzle, which [[StableTimeLoop she only escaped from using the information he sent back to her]].]]
** ''VisualNovel/VirtuesLastReward'': [[spoiler: Sigma and Phi]] are able to project their consciousnesses across different timelines, swapping with their counterparts from those worlds. This allows them to escape the timelines where [[spoiler: they and the other Nonary Game participants end up trapped forever]] or [[spoiler: succumb to [[ThePlague Radical-6]]]], but it's also proven that those worlds still exist even after they leave. [[spoiler: It's revealed that the AB Project's goal of using this to prevent the outbreak of Radical-6 from ever happening, even if Dr. Klim is successful, means the players of this game will still be stuck in their current BadFuture.]]

** An AlternateUniverse counterpart of [[http://www.scp-wiki.net/scp-507 SCP-507]] [[spoiler: (justifiably and correctly)]] worries about this happening, and tries to hide his identity by cooperating with the "real one" to refuse to disclose which of them is "original" to that universe. [[spoiler:Neither is, and their fears prove perfectly founded.]]

** The original series also subverts this by having the Doctor traumatized by seeing an alternate Earth being destroyed in the story "Inferno".

** ''Film/SpiderManNoWayHome'' [[spoiler:subverts this ''and'' combines it with AlwaysSaveTheVillain]]. Upon learning from Strange that [[spoiler:all the villains pulled into the Marvelverse are doomed to die]] back in their own worlds, [[spoiler:[=MCU=] Peter Parker takes Strange's crystal ball and uses it to alter the fates of the rogues from the Franchise/SpiderManTheatricalFilms and Franchise/TheAmazingSpiderMan universes]].

** ''Film/SpiderManNoWayHome'' [[spoiler:subverts this ''and'' combines it with AlwaysSaveTheVillain]]. Upon learning from Strange that [[spoiler:all the villains pulled into the Marvelverse are doomed to die]] back in their own worlds, [[spoiler:[=MCU=] takes Strange's crystal ball and uses it to alter the fates of rogues from the Franchise/SpiderManTheatricalFilms and Franchise/TheAmazingSpiderMan universes]].

* {{Inverted|Trope}} in ''WesternAnimation/RickAndMorty'': in "Rick Potion No. 9", Rick and Morty inadvertently cause the end of the world and the former simply takes them to an alternate universe where they both died and take their counterparts' place, making this an example of an Expendable ''Main'' Universe. Morty is clearly traumatized by the notion that his friends and family are all doomed and he will spend the rest of his life with identical strangers. Given how nonchalant Rick is about this, it's quite clear that he considers ''every'' universe expendable. ''Rickmurai Jack'' reveals that the main Rick has pulled this exact trick at least once before, and he's from a different dimension than the Morty that the show is following (in Rick's original reality, [[spoiler:his family was killed]], which explains a lot about his nihilistic attitude).