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[[quoteright:300:[[Franchise/TheFlash http://static.tvtropes.org/pmwiki/pub/images/1441923-dc_multiverse_super_6505.jpg]]]]

->'''Future Trunks:''' You see, when I travel back to the past, I'm...technically going to a different universe...\\
'''Gohan:''' Oh, you mean Multiverse Theory?\\
'''Future Trunks:''' Wait, what?!\\
'''Gohan:''' Yeah! With every decision, it creates a branch in the timeline! Whenever you travel back in time, you're actually entering another parallel universe!\\
'''Future Trunks:''' How could you possibly...?\\
'''Gohan:''' I've been studying theoretical physics. Although at this point, I guess it's just physics.

Some settings refer to not just [[AnotherDimension one other dimension]], [[AlternateUniverse one other universe]], or [[AlternateTimeline one other timeline]], but to a whole ''set'' of other dimensions, universes, planes of existence, realities, timelines, and the like. A collection of distinct universes exists, said universes often being interconnected in a way that allows characters to travel to and from them. It might be as a tourist who just goes to look and tries not to change anything, or as a participant who goes in and interacts with the people in the other universe.

The multiverse can encompass an infinite number of possible and impossible "moments", some of these linked by tidy and coherent timelines. But there may also be an equal or even greater number of incoherent, looped, knotted, or unconnected timeless moments that remain unchanging for all eternity.

Timelines need not progress forward, or even backward, but also what appears to be sideways through disjointed and unrelated frames of reference. The multiverse may have no apparent ultimate purpose or reason for existence, other than it just is.

Selecting a specific dimensional or timeline destination in the multiverse may be difficult for a traveler. To make sense of this, they may have some relative sense of locality starting from their "home" dimension or timeline, traveling "outward" into the gradually diverging alternate realities around their own. The dimensional expanse is potentially limitless, while the traveler's lifetime and ability to explore and survive them is not.

The method of multiverse travel can be physical or nonphysical. A nonphysical multiverse traveler may be disembodied as a spectator, but may also be able to enter the body of beings to experience what they are experiencing, or to assume direct control. A physical multiverse traveler has additional problems of survival to deal with, such as breathable air, correct temperature, pressure, and gravity, plus also unknowns such as foreign microorganisms. And at the same time a physical dimensional traveler can unintentionally affect the worlds they visit, with their own viruses or bacteria, and not just by what they say or do.

The multiverse permits changing of timelines in a personal sense. Going back in time to change something simply causes the travelers to experience an altered timeline going forward from that change. The original timeline also still exists and progresses normally, at the moment they left.

Damage to timelines in the multiverse by a time traveler can be impossible, since all forms of damage and all timelines where it occurs may already exist but are simply not experienced, because the differing timelines can converge and reuse the same spatial moments of existence without themselves intersecting.

The multiverse can also solve the problem of free will vs predestination. It is possible that the multiverse is static and unchanging. All things that can ever exist already exist somewhere within it. But because there are a possibly infinite number of timelines converging and diverging from every moment into an equally huge number of alternate realities, predestination becomes irrelevant since normally only one of these timelines is experientially traversable.

The definition of the self and the individual becomes vague, because there can be an equally infinite number of "selves of me" all traversing the timelines simultaneously. Only a privileged few of these may gain the ability to break free of the restrictions and cross between timelines or experience other timelines completely unrelated to their own.

The need to achieve anything and the ability to create anything new becomes irrelevant if the ability to easily traverse the infinitely varied timelines of the multiverse becomes possible. One can simply choose to experience a point in a timeline where the achievements have already occurred, or the desired thing was already created and carried out to its fullest form.

Morality becomes a question of what timelines and time periods that a multiverse voyager allows themselves to experience and be aware of, because the worst atrocities imaginable already exist in every possible form and can not be prevented. One can only choose to experience the kinder, gentler timelines, while recognizing the others exist and actively choosing to not experience them.

At the same time, a multiverse voyager can choose to experience atrocious timelines in the multiverse, knowing that they are only responsible for choosing to be aware of them, and not for actually causing any of the events of the timeline, because the events that will occur in those timelines are already fixed and can not be changed. Any attempt at change of the events of a timeline simply results in selection of one of the many diverging paths away from it, which also already exist in every possible form.

Dreaming may involve experiencing incoherent snippets of alternate timelines in the multiverse, as a form of "taking a break" from main normal timeline while sleeping. Lucid dreamers, meditators, and astral travelers may also gain more direct control over these alternate timeline experiences, to experience them more vividly or coherently.

{{Dimensional Traveler}}s can move between universes and explore the Multiverse. While it is possible they don't have a choice in their destination, sometimes they do. There are a wide variety of {{Interdimensional Travel Device}}s available but the most common are [[PortalNetwork gates]] or magic.

In most fantasy settings, the other worlds are often referred to as "planes of existence", and are [[AnotherDimension alternate dimensions]]. In most science fiction settings, the other worlds are often [[AlternateUniverse entire parallel universes]] or [[AlternateTimeline alternate timelines]].

On some occasions it's the way for a creator to tie several different works via CanonWelding, or to justify a {{Crossover}}.

This provides all sorts of interesting ideas for things you can do, for good or bad. If it involves trans-universe SexTourism, you have YourUniverseOrMine (or ScrewYourself sometimes). However, beware EvilTwin, and similar beings.

Sometimes, the Multiverse is protected by a GuardianOfTheMultiverse. The MultiversalConqueror, on the other hand, wants to [[CaptainObvious conquer]] or [[OmnicidalManiac destroy]] it.

It is '''not''' the same thing as AlternateContinuity - which refers to a ''separate'' universe which a work has (but that might equally have its own {{Multiverse}} within its {{Continuity}}), but it makes for a handy way to link them if the writers are so inclined.

See also BizarroUniverse, AnotherDimension and AlternateUniverse. Compare RubberBandHistory. If one universe acts as a CosmicKeystone that the others are based on, that's TheEarthPrimeTheory.

For works set in the same series franchise, see TheVerse and IntraFranchiseCrossover.



[[folder:Anime and Manga]]
* ''Manga/{{Bokurano}}'': The main characters are [[HumongousMecha fighting aliens]] who are [[TheEndOfTheWorldAsWeKnowIt attempting to destroy the Earth]]. Eventually it is revealed that [[spoiler:the aliens are [[AnotherDimension actually humans from alternate Earths]]. The Earths tend to be fairly similar and can easily be mistaken for one another (which the main characters did), though [[IdenticalStranger alternates of individuals from one world to another]]]] are very rare.
* This concept is briefly utilized in ''Anime/CrossAnge'' to explain the motivations of its villain, Embryo. And to show how the [=DRAGONS=] are able to co-exist in the same timeline as the show's [[spoiler:current Earth.]]
** [[spoiler:Said villain's motivations lead into OmnicidalManiac territories by the finale, as it suggests that he ventured outside his ''own'' universe and '''''blew up''''' other planets to conduct his experiments.]]
* While on the surface ''Franchise/{{Digimon}}'' appears to be a case of regular {{continuity reboot}}s, the UsefulNotes/WonderSwan video games establish it instead as a multiverse. Almost every anime series, manga and video game of the franchise has its own entirely separate versions of the real and Digital World (except ''Anime/DigimonAdventure02'' and ''Anime/DigimonXrosWarsTheYoungHuntersLeapingThroughTime'', which are sequels and so exist in the same world); the UsefulNotes/WonderSwan games follow Ryo Akiyama's travels between a few of them. ''Manga/DigimonVTamer01'' had three special chapters in which [[TheHero Taichi Yagami and Zeromaru]] interact with other ''Digimon'' universes, namely those of ''Anime/DigimonAdventure'' (which has its own version of Taichi Yagami), ''Anime/DigimonFrontier'' and the UsefulNotes/WonderSwan games. As such, almost all incarnations of ''Digimon'' take place in a different human world/Digital World pair in the multiverse, and if you know what you're doing (or have a dimension-jumping nemesis, in the case of [[VideoGame/DigimonAdventureAnodeCathodeTamer Ryo Akiyama]]) you can travel between them. In addition, some canons have other dimensions tied to that particular universe; ''Anime/DigimonAdventure'' had the Dark Ocean and a surreal world wherein one's wishes defined reality, with others accessible through card combinations at a gate in Vamdemon's castle, and ''Anime/DigimonXrosWarsTheYoungHuntersLeapingThroughTime'' features [=DigiQuartz=], a bizarre DarkWorld in between the Real and Digital Worlds.
* ''Manga/DragonBall'':
** ''Battle of Gods'' introduces the concept of the Multiverse with the God of Destruction Beerus stating that there are twelve universes in total and the main cast comes from the seventh one. ''Anime/DragonBallSuper'' elaborates by saying that every pair of universes whose numbers adds up to 13 is a matched set; Universe 7's partner is Universe 6, with Beerus' brother Champa serving as its God of Destruction and eventually challenging Beerus and the Z-Fighters to an inter-universal tournament.
*** Above all twelve universes is Zen'o-sama, the King of Everything. According to Whis, there used to be ''eighteen'' universes until Zen'o destroyed six of them when he was in a bad mood. Then in the Universe Survival Saga, he decides that watching twelve universes is too much work [[spoiler:(even with [[MyFutureSelfAndMe two of himself]])]] and announces that he'll be paring it down to ''five''. The universes are ranked by their level of development, and the bottom eight have to participate in a Battle Royale to see who will get to continue existing alongside the top four.
** ''DBZ'' indulged in this even earlier, where Future Trunks and Cell's attempts to time-travel turned out to be unintentional dimension-hopping. This series of events accounts for about three parallel worlds: The main DBZ universe, Trunks' timeline, Cell's timeline, plus a fourth speculated upon by official guidebooks[[note]]Which would be the timeline that the Trunks of Cell's timeline visited[[/note]].
** According to ''VideoGame/DragonBallXenoverse'' and [[VideoGame/DragonBallXenoverse2 its sequel]], the events of ''VideoGame/DragonBallGT'' and the [[NonSerialMovie Non-Serial Movies]] exist in alternate timelines. The antagonists screwing with time thus allows them to appear in the games' storylines despite their non-canon status.
* Though not confirmed officially, the ''[[Anime/NeonGenesisEvangelion Evaverse]]'' is implied to use this trope between the various continuities and spin-offs. Kaworu appears to be aware of and/or remember ''every single one'', including the anime, the mangas, the games, even the ''[[Anime/RebuildOfEvangelion Rebuild]]'' films.
* ''Anime/GenesisOfAquarion'' eventually goes this route: the OVA's are explicitly set in a different but co-existent timeline from the series, and the repercussions of what happens in the OVA-world has slight effects on the TV series-timeline. This also becomes a plot point in ''Anime/AquarionEvol'', as [[spoiler:it turns out that the Abductors are from an alternate version of Vega (the planet the series takes place on), which split off somehow during the events of the ''Genesis'' finale.]] A crossover OVA between ''Genesis'' and ''Evol'' makes a passing mention to ''seven'' different worlds existing as a result of the ancient war in ''Genesis'''s backstory, and deals with the consequences of what happens when a couple of those worlds begin to bleed into each other.
* In ''[[Manga/YuushaGojoKumiaiKouryuugataKeijiban Hero Union BBS]]'', the setting of the story spans multiple universes. Characters from different universes can be transported to another via summoning magic or communicate with each other via the forum. Only powerful heroes who have reached Level 8 or above can traverse the multiverse at will by mastering space-time magic.
* ''Manga/KatekyoHitmanReborn'' has [[spoiler:Byakuran]] become a PhysicalGod of all parallel universes, using the [[MacGuffin three sets of rings and pacifiers]] in order to do so.
* The setting of ''Franchise/LyricalNanoha'' is advanced enough to have fairly casual inter-dimensional travel, with the [[TheFederation Time-Space Administration Bureau]] monitoring the security, safety, and cultural growth of every dimension.
* The setting of the ''Anime/MazingerZ'' franchise is this: ''Manga/ShinMazingerZero'' established that the original ''Anime/MazingerZ'' timeline and all alternate timelines and realities seen in the story are part of a multiverse which includes the universes of ''Anime/GreatMazinger'', ''Anime/UFORoboGrendizer'', ''Manga/GetterRobo'', ''Anime/KotetsuJeeg'', ''[[Anime/MobileSuitGundam UC Gundam]]'', ''Anime/{{Gunbuster}}'' and ''Anime/NeonGenesisEvangelion'', among others.
* From some point of the series onward,[[spoiler: Hatou]] in ''Manga/MurasakiiroNoQualia'' can interact with all the [[AlternateUniverse parallel worlds]]. Each of these is one of the infinite possibilities for the flow of events that didn't get determined in her world.
* ''Anime/{{Noein}}'' has this where every universe is a ForWantOfANail situation, running off the theory that for every decision made, AnotherDimension is created where the other option was chosen. [[ContemplateOurNavels Much philosophy ensues]].
* ''LightNovel/{{Slayers}}'' takes place in one (sometimes called “the red world”) of four universes, each of which has a good and evil god with five subordinates a piece, all projections floating atop a multiversal golden sea of chaos, A.K.A. [[spoiler: The Lord of Nightmares]]. This doesn't really come into play for the most part, aside from in the anime-original ''TRY'' season, which concerns “overworlders” searching for five PlotCoupon weapons from their universe…
* ''Anime/TenchiMuyo'' is the one ''huge'' metaseries with literally ''tens'' of alternative continuities, explored in various TV series, [=OVAs=], [[AllThereInTheManual novels, mangas, doujinshis]] etc. It also includes other series and titles by the same author and studio, and even the works by the other creators with sometimes completely different premises. It was [[WordOfGod explicitly stated]] by its creator, Masaki Kajishima, that ''[[AllMythsAreTrue all]]'' [[AllMythsAreTrue these titles and interpretations are true]] and represent different aspects of the same Multiverse, and he doesn't mind sharing. On the other hand, he restricts himself to the ''[[Anime/TenchiMuyo Tenchi Muyo! Ryo-Oh-Ki]]'' (that is, original [=OVAs=]) storyline and its spinoffs like ''Anime/TenchiMuyoGXP,'' and considers it the main and central storyline.
* ''Anime/TengenToppaGurrenLagann'': Three Words: Multi-Dimensional Labyrinth. The Anti-Spiral effectively flings the consciousnesses of every member of Team Dai-Gurren to [[LotusEaterMachine separate alternate realities without their true memories.]] According to the Anti-Spiral, these realities are "created instant-to-instant as they are perceived." It is also stated that the Anti-Spiral home world is hidden in-between the 10th and 11th dimensions. Finally, most of the final episode takes place [[spoiler: in a "super-spiral universe where thought is given form."]]
* ''Franchise/WhenTheyCry'' uses and abuses this concept for its [[GroundhogDayLoop Groundhog Day Loops]]. The multiverse can be viewed only in the sea of kakera/pieces/fragments. In that sea, each fragment is essentially one possible path that the world can take. ''VisualNovel/UminekoWhenTheyCry'' introduces the idea of voyager witches, such as Bernkastel and Lambdadelta, who are the only beings capable of traveling the different fragments, and creator witches, who are the only ones capable of creating new fragments.
* Yuuko from ''Manga/XxxHolic'' is called the Witch of Dimension for her ability to create gates to any AlternateUniverse. It's her services which allow the cast of ''Manga/TsubasaReservoirChronicle'' to hop for one dimensions to another trying to collect all the [[GottaCatchThemAll feathers]].

[[folder:Comic Books]]
* ''ComicBook/BlackMoonChronicles'': Apparently reality is made up of many different dimensions tied together by the four elements. After humanity leaves the Earth for a different world when it is about to be destroyed, it takes Lucifer one hell of an effort to find humanity again between all the different universes.
* Major staple of Franchise/TheDCU and Franchise/MarvelUniverse comics (although DC attempted to get rid of it in the '80s; it's back now after the events of Comicbook/InfiniteCrisis and Comicbook/FiftyTwo).
** After several cosmic upheavals, taking DC's number of universes from infinite to one to fifty-two, the DC Multiverse now consists of infinite universes grouped into sets of 'bubble' Multiverses suspended in a larger structure that Creator/{{Grant Morrison}} refers to as the Multi-Multiverse, these bubbles each having a different number of universes within. The 'local Multiverse' that the main DC Universe is set in is made up of 52 universes, some of which are recognizable from various {{Elseworld}}s stories, some of which are wholly new creations or amalgamations of worlds from before the original Comicbook/CrisisOnInfiniteEarths, [[spoiler: itself undone by the events of ComicBook/{{Convergence}}, restoring the infinite Earths destroyed there]]. Comicbook/{{Earth 2}} of the ComicBook/{{New 52}} deals with events that happen on one of these Earths, and Creator/{{Grant Morrison}}'s ''Comicbook/TheMultiversity'' series has six of its issues each dedicated to one Earth within the local Multiverse, plus a multiverse guidebook, with plans to explore these Earths and those beyond further in ''Multiversity Too''. These 'local' universes are:
*** Earth-0, the main DCU.
*** Earth-1, the world home to the ''Earth One'' line of graphic novels, with young and inexperienced versions of the main DC heroes just beginning to appear, including Superman, Batman, Wonder Woman, Flash, Aquaman and the Teen Titans.
*** Earth-2, as featured in [[Comicbook/{{Earth 2}} the comic of the same name]], where younger versions of DC's Golden Age heroes arose in the modern day in the wake of an invasion from Apokolips that killed Superman, Batman and Wonder Woman.
*** Earth-3, the MirrorUniverse of Earth-0, ruled by the Crime Syndicate of America [[spoiler:until the Anti-Monitor destroyed it in ''Comicbook/ForeverEvil'']].
*** Earth-4, where the Creator/CharltonComics characters -- Comicbook/TheQuestion, Comicbook/BlueBeetle, Comicbook/CaptainAtom, etc. -- are the heroes of a ''Comicbook/{{Watchmen}}''-influenced world.
*** Earth-5, the world of [[Comicbook/{{Shazam}} Captain Marvel]] and the Marvel Family.
*** Earth-6, the world now home to the stories from ''Comicbook/JustImagineStanLeeCreatingTheDCUniverse''.
*** Earth-7, an ''Comicbook/UltimateMarvel'' pastiche (later including elements of [[spoiler: ComicBook/MarvelZombies]]) that was destroyed by the Gentry in ''Multiversity''. However, pastiches of DC characters can be seen among the dead, so it's likely this Earth was a mix-up in homage to the many DC and Marvel crossover stories; it also had an equivalent to ''ComicBook/{{Hellboy}}''.
*** Earth-8, a Creator/MarvelComics pastiche, for example featuring the [[ComicBook/TheAvengers Retaliators]] and the [[Comicbook/XMen G-Men]].
*** Earth-9, the Creator/TangentComics universe, with characters that have the same names as the main DCU heroes but are otherwise entirely different.
*** Earth-10, a world where Kal-L was found by the Nazis, and grew up to become Overman. With the help of retro-engineered Kryptonian technology -- and, when he was old enough, Overman himself -- the Nazis won UsefulNotes/WorldWarII. [[MyGodWhatHaveIDone In guilt over the Nazis' atrocities]], Overman turned his Earth into a pseudo-utopia; the last English-speaking rebels, [[Comicbook/FreedomFighters Uncle Sam and the Freedom Fighters]], fight Overman's New Reichsmen.
*** Earth-11, which includes [[GenderFlip female versions of the main DCU's heroes and villains, and male versions of its heroines and villainesses]]. This is a world where the Amazons of Themyscira had greater influence on society's advancement, to the point that women were given more freedom and helped shape Earth's future.
*** Earth-12, the ''Franchise/{{DCAU}}'' world, currently in the era of ''WesternAnimation/BatmanBeyond''.
*** Earth-13, home to a dark, magical Justice League called the League of Shadows, including [[Comicbook/{{Etrigan}} Superdemon]], Comicbook/{{Hellblazer}} (based on the Batmanesque version from ''Comicbok/DoomPatrol'' #53 and ''Comicbook/BooksOfMagic'' Annual #3), and [[Comicbook/DoctorFate Fate]] (the 90s version with the ankh scar). The world is in a state of perpetual twilight, there are 13 months in the year, and 13 hours in every day.
*** Earth-15, a perfect world that was destroyed by Superboy-Prime. All that's left is a Cosmic Grail that was hidden in another world.
*** Earth-16, with the children of the main DC universe's heroes and villains -- Chris Kent as Franchise/{{Superman}}'s son, Damian Wayne as Franchise/{{Batman}}'s son, etc. -- plus DC's '90s supers, who live as shallow celebrities with all evil having been wiped out by the previous generation.
*** Earth-17, an Earth ravaged by atomic destruction. Humanity lives in domed cities, and the Atomic Knights of Justice are led by Adam Strange.
*** Earth-18, a Western-style world featuring the Justice Riders, who ride on SteamPunk horses. On this world, the [[ComicBook/{{Legion of Super-Heroes}} Time Trapper]] froze the state of progression so that, even with many 21st Century based technological advances, society is still a frontier world.
*** Earth-19, a world currently in the era of Edwardian England, home to the Bat Man, the Wonder Woman, the Accelerated Man, and the Shrinking Man. Bruce and Diana are based on ''Gotham By Gaslight'' and ''Amazonia'' respectively [[note]]Although those books have completely different UsefulNotes/{{Jack the Ripper}}s, so can't actually be the same universe[[/note]].
*** Earth-20, a [[TwoFistedTales pulp-style world]] featuring [[Comicbook/DoctorFate Doc Fate]] and the Society of Super-Heroes, who include Abin Sur's Franchise/GreenLantern, Immortal Man, the Mighty Atom, and the Blackhawks.
*** Earth-21, the 1960s ''ComicBook/DCTheNewFrontier'' universe, where John F. Kennedy was never assassinated and the Justice League of America protects a newly spacefaring USA.
*** Earth-22, the ''ComicBook/KingdomCome'' universe where a new generation of heroes has run amok, forcing Superman and his allies to come out of retirement to try and fix things.
*** Earth-23, home of President Superman, where the world's greatest heroes are black (which can mean that they're black in the main DCU, as with Steel and Vixen; that a black holder of the legacy in the main DCU is Earth-23's primary holder, as seems to be the case with Green Lantern; that they're black versions of the hero, as with Superman; or that they're completely unique). The major exception is Batman.
*** Earth-26, an AlternateTooniverse where ComicBook/CaptainCarrotAndHisAmazingZooCrew reside.
*** Earth-29, the cube-shaped BizarroUniverse.
*** Earth-30, the ''ComicBook/SupermanRedSon'' universe where Superman landed in Russia and became the leader of the USSR.
*** Earth-31, a world ravaged by tsunamis and earthquakes, where modern pirates roam the seas. Captain Leatherwing and his crew of the Flying Fox act as a force for good.
*** Earth-32, a world partially based on ''Batman: In Darkest Knight''. Bruce Wayne is Green Lantern, and fights alongside heroes such as Super-Martian, Wonderhawk, and Aquaflash in the Justice Titans.
*** Earth-33, a.k.a. Earth-Prime, our own real world.
*** Earth-34, an ''ComicBook/AstroCity'' pastiche, home to [[ComicStrip/LilAbner Goodfellow]] and the heroes of Cosmoville.
*** Earth-35, a pastiche of Rob Liefeld's ''Extreme Studios'' comics, including [[ComicBook/{{Supreme}} Supremo]] and Majesty, Queen of Venus. The premier superteam of this world is the Super-Americans.
*** Earth-36, a world home to a team called Justice 9, based off ''Big Bang Comics'', whose main hero Optiman has been killed by Super-Doomsday of Earth-45.
*** Earth-37, a world based off the works of author Howard Chaykin, such as ''Batman: Thrillkiller'' and Twilight.
*** Earth-38, the ''Comicbook/SupermanAndBatmanGenerations'' universe where Superman debuted in 1938 and Batman followed in 1939; they aged normally and had families, including the modern scion of both, Knight-Wing.
*** Earth-39, a world based off the works of artist Wally Wood, home to the [[Comicbook/THUNDERAgents Agents of W.O.N.D.E.R.]]
*** Earth-40, an EvilCounterpart to Earth-20 where villains rather than heroes triumph, featuring ComicBook/LadyShiva, ComicBook/VandalSavage, Count Sinestro, Blockbuster, and Doctor Felix Faust as the Society of Super-Villains.
*** Earth-41, home to [[Comicbook/{{Spawn}} Spore]] and [[ComicBook/SavageDragon Dino-Cop]], a world where so many heroes differ in terms of style and ideology, it's as if they were each dreamed up by individuals who had [[Creator/ImageComics specific images and ideals of their heroes]].
*** Earth-42, home to imp-like versions of the Justice League known as the Li'l Leaguers. [[spoiler: They're actually robots.]]
*** Earth-43, which has a Vampire League and is home to the ''Comicbook/BatmanVampire'' Elseworlds trilogy.
*** Earth-44, the world of the Metal League, a fusion of the Justice League and the Comicbook/MetalMen, led by Doc Tornado.
*** Earth-45, an Earth where Superman as a concept became perverted and corrupted by mass marketing and turned into the hyper-edgy Superdoomsday, whom later went on a homicidal rampage killing the Supermen of other Earths before being stopped by the Superman of Earth-0 in ''ComicBook/GrantMorrisonsActionComics''.
*** Earth-47, a world where TheSixties never ended, home to the Love Syndicate of Dreamworld and immortal teenage president Prez Rickard.
*** Earth-48, the new home to Lady Quark and Lord Volt. A world bred as protectors of the Multiverse, where everyone is a superhero and every event is a Crisis Crossover.
*** Earth-50, home to the Justice Lords from the DCAU.
*** Earth-51, the world of Creator/JackKirby's DC creations such as Kamandi and OMAC.
*** The guidebook covers 45 of the Earths, leaving 7 over for other writers to develop: 14, 24, 25, 27, 28, 46 and 49. There is also mention of Hypertime, a former method of incorporating infinite universes devised by Morrison and Mark Waid.
*** Earth-14 shows up in the ''ComicBook/SupermanRebirth'' story "Multiplicity", where it's home to the Justice League of Assassins. From what's shown, it looks to be an AfterTheEnd ''Film/MadMax''-style world.
*** Earth-1098 is the ''ComicBook/ElseworldsFinestSupergirlAndBatgirl'' universe, where Kal-El died before becoming Franchise/{{Superman}} and Bruce Wayne never became Batman. ''Comicbook/{{Batgirl}}'' - Barbara Gordon - is Gotham's near-dictatorial protector, Franchise/WonderWoman leads the Justice Society and is ''Comicbook/{{Supergirl}}'''s - Kara Zor-El - foster mother, and ''Comicbook/LexLuthor'' backs - and manipulates - the Society.
*** Morrison drew up [[http://robot6.comicbookresources.com/wp-content/uploads/2014/07/multiversity-map.jpg a map of the DCU multiverse]] as it stood circa ''The Multiversity''. Basically, the entire multiverse exists on a vibrational spectrum from red (matter) to blue (thought). At the centre, covering red and orange, is the Orrery of Worlds, with the 52 universes and the [[Comicbook/{{Shazam}} Rock of Eternity]] contained within the Bleed. Marking the boundary of the Orrery is the [[Franchise/TheFlash Speed Force Wall]]. Further out, from yellow to green, is the Sphere of the Gods, containing all of the DCU's various gods and archetypes -- this is where [[Comicbook/NewGods Apokolips, New Genesis]], [[Comicbook/TheSandman the Dreaming, the Silver City]], etc., are. At the border of the Sphere is Limbo, where the lost and forgotten of the Orrery end up, characters like Merryman that were lost to history. Blue is the Monitor Sphere, where the Monitors used to oversee the Orrery before their unmaking in ''Comicbook/FinalCrisis''. Marking the final boundary of the multiverse, and the limit to thought, at furthest blue-shift is the Source Wall, beyond which is the Overvoid, where lie the Monitor-mind that spawned the Monitors, the Source, and the Unknowable; in Morrison's conception, [[FourthWall the white of the printed page panel borders in which all comics are enclosed.]]
*** One thing that should be noted about DC's local multiverse is that the universes are connected through comic books, [[RecursiveCanon each Earth producing comics that recount what's happening somewhere else in the multiverse, even if most people think they're fictional]]. This has long standing at DC - in the Silver Age, Earth-One's Flash, Barry Allen, read comics about Earth-Two's Flash, Jay Garrick.
** The Creator/{{Wildstorm}} multiverse consists of a [[http://en.wikipedia.org/wiki/Monster_group 196833-dimensional]] snowflake-shaped arrangement of universes, flat sheets of information that their inhabitants interpret as three-dimensional (or what have you). Between them is [[SubspaceOrHyperspace the Bleed]], red swirly stuff of vaguely-defined properties. The Bleed, if not the snowflake, was incorporated into Franchise/TheDCU.
*** After the ComicBook/{{New 52}} reboot/relaunch in 2011, there is no known "Wildstorm multiverse" anymore, with all the Wildstorm characters and stories incorporated into the rebooted DC Universe. It may still exist, however, somewhere within the larger 'Multi-Multiverse'.
*** 2017's rebooted Wildstorm universe is separate from the DCU, with both having their own versions of Wildstorm characters. As yet, the rebooted 'verse has no assigned number.
** Franchise/TheDCU and Franchise/MarvelUniverse are also part of one omniverse as evidenced by crossovers that have been referenced later by both companies (making them canon). Both also contain multiple alternate futures and the characters from the past and future of other universes. Now, go back and read that again.
** Creator/WarrenEllis' run on ''ComicBook/XMan'' utilized another conception of the multiverse, where in addition to ParallelUniverse[=s=], there's a "spiral of realities" stretching above and below, with the universes "downspiral" being significantly more chaotic and difficult for life to develop/survive in than the the relatively advanced and idyllic universes located "upspiral".
** There are in fact two types of alternate universe in the Marvel Universe. The first are different dimensions adjacent to the regular 616 verse, such as the Microverse and the various magical verses; the second are parallel universes, which are usually alternate timelines, and presumably each has its own adjacent verses too. It's not always clear which is which -- the Negative Zone, for instance, is vague on if it is the first or second kind, so the one encountered by the regular ComicBook/FantasticFour and their Ultimate counterparts could actually be one and the same (and the Nihil encountered by the latter wasn't a counterpart of the regular FF foe Annihilus, but a member of the same species -- [[FridgeBrilliance which is why he referred to himself as a member of a "caste" and already knew who Reed Richards was in their first meeting]]).
* The comic ''ComicBook/{{Fables}}'' mainly features our own world, but also a indefinite number of Fairy Tale worlds which are connected by gates. The gates to our world are closely guarded by the New York Fables since they were conquered by the [[BigBad Adversary]].
** This latter plays a role in the War against the Adversary.
* So did the comic book ''Grimjack''.
* Issues #17-20 of ''ComicBook/MyLittlePonyFriendshipIsMagicIDW'' features a magic mirror that takes explorers to various {{Alternate Universe}}s. The focus of the arc is on one BizarroUniverse, with evil versions of the good characters and vice-versa. The crisis occurs because good!Celestia falls in love with the alternate world's King Sombra, but their travels have weakened the bonds separating the realities, allowing evil!Celestia to try and take over both.
* ''ComicBook/PathfinderWorldscape'' takes place in a demiplane that draws living beings from three separate worlds - Earth, Golarion (TabletopGame/{{Pathfinder}}'s setting) and Barsoom (better known as the planet Mars where ''Literature/JohnCarterOfMars''/''ComicBook/WarlordOfMars'' takes place), and even individuals from different versions. For example, ComicBook/RedSonja and Kulan Gath hail from the [[Franchise/ConanTheBarbarian Hyborian Era]], a period in Earth's pre-history that is radically different from the Earth that John Carter came from. Likewise, the White Martians encountered in the Worldscape are noted by Carter to not being the same ones he fought in his past and they must have belonged to another version of Barsoom.
* Very early on, the Archie ''Comicbook/SonicTheHedgehog'' comic parodied the DC multiverse with a literal "superhighway" connecting the various worlds. In a "Bizarro" universe, Dr. Eggman is a kindly veterinarian, while Sonic and his cohorts are evil hooligans in biker outfits. In another, Dr. Eggman was nearly defeated by the Freedom Fighters, but turned himself into a robot as a last resort (and he's even more kill-crazy than the original).
** Every Sonic game and television show is in canon, except that most exist in multiple universes, or 'Zones'. This includes: The 'Prime' Universe, the VideoGame/{{Sonic Rush|Series}} Dimension, the WesternAnimation/SonicUnderground Universe, the (inevitable) ComicBook/SabrinaTheTeenageWitch crossover, and a ''Franchise/SailorMoon''-inspired universe where Knuckles wears a tuxedo. Go figure. The "real" world is yet another universe, and features lawyer-friendly versions of Fox Mulder and Dana Scully, hot on the trail of a giant blue talking hedgehog. (''Sonic Live'')
*** The lawsuit-forced CosmicRetcon following ''ComicBook/SonicTheHedgehogMegaManWorldsCollide'' caused the entire multiverse to collapse on itself and be reborn. That basically put a stop to the universe hopping in the entirety of the comics, and the concept died completely when the comics were cancelled in 2017.
* The comic books ''ComicBook/ThoseAnnoyingPostBros'' and ''ComicBook/SavageHenry'' focus on Bugtown, a infinite-sized CityOfAdventure which connects to an infinite number of alternate worlds.
* ''ComicBook/{{Zenith}}'', a ''[[ComicBook/TwoThousandAD 2000 AD]]'' series, features this. Perhaps not surprisingly, its author Creator/GrantMorrison is one of the creators responsible for bringing back the DC multiverse.

[[folder:Fan Works]]
* Creator/AAPessimal has created several ongoing tales concerning the ''Literature/{{Discworld}}'' contacting various aspects of "Roundworld" (see below). Ponder Stibbons, who is perhaps more of a research and theoretical physicist than a Wizard, finds himself among congenial like minds when he visits the Roundworld of ''Series/TheBigBangTheory'' in ''Fanfic/TheManyWorldsInterpretation''. His Assassin girlfriend [[IWantMyBelovedToBeFashionable also finds friends she can bond with]] in Penny, Bernadette and Amy. In future chapters, Sheldon Cooper and the gang get to visit the Discworld. Mayhem and misunderstanding ensue.
** In another fic, ''{{Doppelgangers}}'', the loose ends concerning Rincewind's temporary visit to Earth as Professor van Rijnswand are dealt with. It is discovered that all Discworld people have identical body doubles on Earth. This explains a lot.
* The ''Fanfic/BloodyRoseSeries'' is a metaseries of different fanfiction series in a shared multiverse, starring the Japanese pop idol group AKB48.
* The ''FanFic/BloomingMoonChronicles'', as its alternate name, ''The 99 Worlds Saga'', suggests, features many different alternate worlds revolving around a single core world (the world as depicted in ''WesternAnimation/MyLittlePonyFriendshipIsMagic''). The further away a world is from the core, the greater the differences between that world and the TV show.
* [[http://www.fanfiction.net/s/3990441 The Chance Encounter crossover series]] Uses this as a plot device, with the main characters hopping around a collection of universes (LOTR verse, Kingdom of Heaven verse, POTC universe and the Troy universe), mostly by means of shipwreck.
** The travel method has become something of a RunningGag, with one of the main characters (Balian) being regularly advised to stay on land. Even that doesn't work. Mostly they tend to arrive in tree's, leading to Legolas remarking that whoever organises these jumps has a serious lack of imagination.
* Used in ''Franchise/CodeGeass: [[http://www.fanfiction.net/s/8514740/1/Occulta-Rising Occulta Rising]]''.
* Fanfic/CodePonyEvolution uses this to explain how the worlds meet.
* Fanfic/CrossoverChaos takes this trope and runs with it, not only in terms of CanonWelding all the series featured (as well as RealLife) into one functioning universe, but also the fact that there are many alternate versions of the main universe, which the main universe characters have gone into, and met people from, countless times before. It's implied every piece of fiction ever does, did, and will exist pretty much exists in multiple forms within the series' multiverse, and the same goes for RealLife as well.
* ''Fanfic/ACrownOfStars'': Throughout the history Asuka and Shinji travel between dimensions several times and meet several of their other-worldly counterparts. [[GodEmperor King of Avalon Daniel]] rules a chunk of the multiverse. He has seen and visited many alternate realities.
-->'''Ching''':''“Infinite universes, almost anything happens. ''Literature/DoctorFaustus'' happened somewhere, ''Literature/TheIliad'' happened somewhere, and ''Anime/NeonGenesisEvangelion'' happened somewhere. Your world was a darker story of what might have come next.”''
* The premise of ''Fanfic/EggmanGenerations'', with three versions of Eggman gathering a group of their alternates, so that they can come up with a clan to beat Sonic.
* ''Fanfic/TheEmiyaClan'' runs on this. With a few exceptions (the Shonen Jump big three, Warhammer 40k, ''Manga/FairyTail'', DBZ, and a couple others forbidden by the community) every fictional universe is stated or implied to exist somewhere and in some capacity. As such, the possibility for shout outs and crossovers is huge. Whether through [[TimeyWimeyBall time travel]], [[DimensionalTraveler dimension hopping]], [[SpaceIsAnOcean space]], or [[AWizardDidIt magician relatives]], any idea can make an appearance so long as the authors approve it.
* Creator/{{Evilhumour}} has one that ties in a lot of his ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' fanfics, with at least thirteen (or more) universes in a set of linked but separate versions of Equestria. These universes include the Blinds-verse, Broken Star-verse, Cassius-verse, Diplomatic Visit-verse, [[FanFic/EscapeFromTheMoon Doa-verse]], Galloping Waves-verse, [[FanFic/DeathIsForcedToTakeAVacation Harvest-verse]], [[FanFic/ThePiecesLieWhereTheyFell Pieces-verse]], Reflecting Shield-verse, Testing-verse, [[FanFic/AChanceMeetingOfTwoMoons Two Moons-verse]], ''Survival'' and ''Twisted Fate''.
* Major staple in ''FanFic/Hottie3TheBestFanFicInTheWorld'' on the count of it being a MegaCrossover. There is also the concept of the omniverse, a [[UpToEleven multiverse of multiverses]]. There are a total of thirteen multiverses in the omniverse.
* ''FanFic/TheInfiniteLoops'' start because the computer the multiverse runs on had a system crash.
* JLA Watchtower and Roleplay/DCNation laughed off "52 Pick Up" (as referenced above), going with the older concept of Hypertime.
* The author [[https://www.fanfiction.net/u/50988/Kanius Kanius]] and his contributors has their concept by having [[Franchise/SailorMoon Sailor Cosmos]] [[Main/GuardianOfTheMultiverse living in the Galaxy Cauldron]] to connect many nexus dimensions. This is where the universes of ''FanFic/DigimonFusionKai'' (DF-616), ''FanFic/YuYuGiDigiMoon'' (YYGDM-01), and [[https://www.fanfiction.net/s/6561565/1/Digimon_Accel_Stream Digimon Accel Stream]] (XLR-8) exist to have their stories as part of ‘the Triad’.
** An alternate future of Digimon Fusion Kai called ‘DF-811’ is where a Future Trunks expy lived and travel back in time to the main DF-616 dimension. The Crystal Tokyo timeline is a separate dimension that's part of YYGDM-01's future. At some point, the dimension of ''Anime/DigimonXrosWars'' is involve with them.
** There are also other universes that references them such as ''Fanfic/GuiltyCrownTheLostKingdoms'' (GCLK-1113) alongside ''Fanfic/KaniusProductionAbridged'' (Shared Character Corner, including ''Fanfic/ShinnenNewYear'' that takes place as the series finale).
* [[https://www.fanfiction.net/s/10071423/1/Mirror-Multiverse Mirror Multiverse]] uses this as a plot device, with the main characters hopping around a collection of universes.
* ''Fanfic/MyLittleUnicorn'': Unicornicopia is supposedly part of only one of many dimensions in a multiverse, whose worlds the unicorns can visit. But the author repeatedly mixes up the terms planet and dimension to the point where he refers to the planets themselves as other planes of reality.
** The remake attempted to fix this by saying that they are in fact planets, but transportation between planets is still called "dimension travel".
* The ''FanFic/PonyPOVSeries'' establishes one of these when Applejack looks into [[GateOfTruth the Truth]] and sees a multitude of {{Alternate Universe}}s, many of which are {{Shout Out}}s to other fics or anime/cartoons/television/etc. It's also with noting that the series uses TheMultiverse -- it's stated several times that all of these universes exist, and are all as real as the main series universe. Also, it's mentioned that all these universes are connected to a "[[TheEarthPrimeTheory Heart World]]" (strongly implied to be the canon universe); changes in the Heart World affect the other worlds connected to it, but if these worlds are somehow disconnected from the Heart World [[spoiler:(as AJ does for the POV-verse in "AJ's Dream")]], they are free to continue on their own without being contradicted.
** Of all the universe shown, a couple get special attention and focus. First, there's the "Orangejack" universe, which shows what would have happened has Applejack chosen to stay in Manehattan -- Big Macintosh becomes the Element of Honesty in his sister's place, while she becomes a successful businessmare, meets the love of her life and has children. [[spoiler: Applejack ends up meeting Orangejack, and together they defeat their potential [[SuperpoweredEvilSide Nightmare-self, Nightmare Mirror]].]] The other universe, which gets even more attention, is the [[BadFuture Epilogue timeline]], which shows what would have happened had [[TheBadGuyWins Discord won]] -- he turns the [[BrainwashedAndCrazy discorded]] Mane Six into his [[CoDragons enforcers]], and turns [[VillainWorld the world]] into [[CrapsackWorld Pony Hell]].
** There are also a few bits of RecursiveFanfiction that are written as {{Alternate Universe}}s to the main POV-verse, but so far only [[http://itsfrompeople.deviantart.com/gallery/#/d4rr76c one]] has been declared official by the main author.
* ''Fanfic/RoyalHeights'' works on the concept that there is only one Universe that permits a multitude of dimensions to exist. These dimensions all have their own laws and physics and general rules but the academy and the technology it provides is the main way for the members of these dimensions to interact with one another.
* ''FanFic/StarsAbove'' uses this concept.
** By the same author, the MagicalGirl CrisisCrossover ''FanFic/ShatteredSkies'' establishes a multiverse consisting of five "vertices": the [[Franchise/SailorMoon Sailorverse]] (90s anime and manga/Crystal continuities), the [[Manga/CardcaptorSakura Cardcaptorverse]], all of the [[Franchise/PrettyCure Precure]] continuities up through ''[[Anime/GoPrincessPrettyCure Go! Princess]]'', the [[Franchise/LyricalNanoha Nanohaverse]], and the [[Franchise/MadokaMagica Madokaverse]].
* ''FanFic/TheSubspaceEmissarysWorldsConquest'' is a multiverse of all the video game settings the author can think of.
* The Multiverse plays an important part in [[http://alaxr274.deviantart.com/gallery/33810717 Super Milestone Wars]] and its sequel.
* The Multiverse also plays an important part in ''Fanfic/TheSweetieChroniclesFragments'': each of Twilight's fragments was placed in a different universe, which Sweetie Belle must then travel to and collect.
* The Multi-Dimensional labyrinth concept described by the Anti-Spiral in Anime/TengenToppaGurrenLagann has the potential to incorporate all of Gurren Lagann's Parallel Works, as well as any and all forms of fan-fiction, as canon because the {{Alternate Universe}}s that make up the Multi-Dimensional Labyrinth are created the instant they are perceived.
* ''Fanfic/TheBridge'' eventually develops one of these, as while it starts with just [[WesternAnimation/MyLittlePonyFriendshipIsMagic Equestria]] and Terra (the MegaCrossover {{Kaiju}} version of Earth), it also later adds on [[{{Mordor}} Zenith]], the ''[[WesternAnimation/MyLittlePonyEquestriaGirls Equestria Girls]]'' universe, the [[TrappedInTVLand Power Ponies]] universe and its EG counterpart, as well as a MirrorUniverse of the latter, the Mirror Universe of Equestria from [[ComicBook/MyLittlePonyFriendshipIsMagicIDW the comics]] [[spoiler: and its Terra counterpart]], and in a later crossover story brings in FanFic/TheShimmerverse as another separate universe.
* ''FanFic/TheLoneTraveler'' stories. Basically the author took the idea of QuantumLeap and merged it with a HarryPotter from the [[FanFic/HarryPotterAndTheNightmaresOfFuturesPast Nightmares of Futures Past]] prologue. Something goes wrong with the ritual and Harry begins leaping, not through time, but through the entire multiverse. Stories crop up about him under the moniker '[[TitleDrop The Lone Traveler]]'
* ''Blog/ThePredespairKids'' touches on this concept from time to time, as the story itself gradually moved into an AlternateUniverse for ''VisualNovel/{{Danganronpa}}'', especially after [[spoiler: Mukuro's HeelFaceTurn and Mikan's [[FakeDefector false betrayal]]]]. Besides that, the anons sometimes bring up events or ideas that have yet to, didn't, or couldn't occur as a result of the changes, and are thus treated like alternate universes and timelines.
** ''Blog/AskTheNewHopesPeak'' is both a [[ContinuationFic continuation]] of ''Anime/Danganronpa3'' and takes place in an AlternateUniverse with many of the same [[OriginalCharacter original characters]] that first appeared on ''The Predespair Kids.'' In fact, the two are said to be [[AlternateTimeline alternate timelines]] that split off from one-another.
* ''Fanfic/ThousandShinji'': In the original series, [[TheEndOfTheWorldAsWeKnowIt Third Impact]] created thousands of alternate universes. The "Thousand Shinji" timeline is part of a multiverse which includes the timelines of ''Fanfic/ShinjiAndWarhammer40K'', ''Fanfic/OnceMoreWithFeeling'', ''Fanfic/ChildrenOfAnElderGod'' and ''Fanfic/NobodyDies''.
* ''Fanfic/WeissReacts'' is set in this, along with ''Fanfic/LucinaReacts''. The other verses are accessible by the [[VideoGame/FireEmblemAwakening Outrealm Gate]] and Blake's [[Anime/TengenToppaGurrenLagann Lagann]].
* ''Fanfic/WithStringsAttached'' takes place in or mentions at least six different universes, and Jeft refers to existence as the Infiniverse.
* [[http://fav.me/daag26e Project Dragon]], [[http://fav.me/dadh9g2 Project Wildcat]] and [[http://fav.me/dah5wli Project Hound]], three long lists doccumenting the many versions of Sash Lilac, Carol Tea and Milla Basset (respectively) from ''VideoGame/FreedomPlanet'', with the [[ComicBook/ArchieComicsSonicTheHedgehog No-Zone]] acting as a backdrop. It is a collaborative project, with others able to suggest Lilacs, Carols and Millas to add to the lists, and stories have been made using them, [[http://fav.me/dak2grm such as here]].[[note]]One of the very first was War Lilac, who starred in another of the author's works, ''FanFic/FreedomDiesWithMe''.[[/note]]
[[folder:Films -- Live-Action]]
* The sci-fi thriller ''Film/{{Coherence}}'' explores the idea of AlternateTimelines crossing paths during a TemporalParadox caused by a comet passing earth.
* The BigBad in the movie ''Film/LastActionHero'' discovers since he can cross over to other movies and other worlds, he can bring back the worst of the worst villains. They'll have a formal party: [[Franchise/ANightmareOnElmStreet Freddy Krueger]] and [[Franchise/FridayThe13th Jason]] can supply the meat, Hannibal Lecter can do the catering, etc. And it will all take place in what is apparently the "Real World", because here ''[[CrapsackWorld the bad guys can win!]]''.
* The basic premise of ''Film/TheOne'' is that Gabriel Yulaw defected from a group known as the Multiverse Authority after killing one of his counterparts, which allows him to absorb their power and become more powerful. His new goal in life to destroy every single one of his counterparts and become a God, with the slight problem that, since the collective energy of his counterparts is divided among ''all'' of the survivors, his last counterpart is equally as powerful.
* The setting of ''Film/{{Parallels}}''.

* ''Literature/{{Anathem}}'' by Neil Stephenson combines this with of all things Platonic Epistemology to very severely deconstruct many aspects of the multiverse. For example, atomic nuclei are subtly different between universes so any reaction between molecules from different universes is retarded (i.e. breathing).
* ''Literature/AstralDawn'' by Adam R. Brown tackles this in a somewhat different way, as the multiverse is referred to as the Nursery of Dimensions. A race of extradimensional aliens called the Aash Ra are charged with safeguarding the Nursery. A single universe out of the multitude lies at the heart of the Astral Dawn saga. Because of its nature, it is called the anomalous dimension.
* Variation: Creator/TimothyZahn's ''Cascade Point'' stories feature a faster than light drive system which has the side effect of showing you alternate versions of yourself whenever you activate it, based on different possible outcomes of your life. At least one story features a PhlebotinumBreakdown that drops the ship into one of those universes. It is a Multiverse, but it's not one where you can easily travel between worlds.
* Kate in ''Choices'' by Deborah Lynn Jacobs. After her brother dies, she starts traveling between new universes with only slight changes from her own. For example, in one she was a pushover. In another she was a PerkyGoth. She would usually go to sleep and wake up in a new universe.
* Creator/RogerZelazny's ''Literature/TheChroniclesOfAmber'' has one reality, Amber, which casts an infinite number of Shadows, each one a full world (with Earth among them). The Princes of Amber can travel at will to these worlds by using Tarot cards as portals, or by walking the shadows and altering them until they stand in the world they desire.
* ''The Coming of the Quantum Cats'', while [[SoOkayItsAverage generally forgettable]], has some fun with this trope. The great scientist Dominic Desota invents a machine for travelling between universes, but in one universe it's stolen by [[EvilTwin General Desota]], who aims to become a MultiversalConqueror. Opposing him are the heroes, Senator Desota and Nicky Desota.
* Colin Kapp's ''The Dark Mind'' (also published as ''The Transfinite Man'') uses this. The alternate universes were originally empty until mankind (in the form of the evil Failway Company) discovered them and, basically, turned them into vice dens.
* Stephen King's ''Franchise/TheDarkTower'' series and the numerous books that feed into it (or got sucked into it) is based on the notion that all of the weird alternate realities visited by the Gunslinger, plus all of the alternate continuities of King's earlier books are part of a Multiverse that are all connected by the eponymous tower. All these worlds are apparently subservient to the world in which the fictionalized version of [[AuthorAvatar King]] lives, and the characters discover that they are all in fact being channeled by King the novelist, a la ''Stranger Than Fiction.''
* Creator/DianaWynneJones's series, stand-alones and short stories often feature Multiverses or at least two different alternate realities. Count them:
** ''The Literature/{{Chrestomanci}} Chronicles''
** ''Literature/DarkLordOfDerkholm''
** ''Literature/HowlsMovingCastle''
** ''Literature/TheMagids'' series
** ''Literature/TheHomewardBounders''
** ''Literature/ASuddenWildMagic''
** ''The Game''
** ''Everard's Ride'' (this one's a novella)
** "Dragon Reserve, Home Eight" (this is a short story)
** One might theoretically consider ''Literature/ATaleOfTimeCity'' as well. Time City is not technically another world per se, but it runs along the much of the same ideas.
* The Literature/{{Discworld}} novels often allude to a multiverse. Since all libraries, everywhere, in every space, universe and time are connected, you can reach this L-space in the Library of Unseen University. If the Librarian lets you in, of course.
** Also, in ''The Colour of Magic'', Rincewind and Twoflower briefly find themselves occupying/incarnated in/deluded into thinking they are alternate universe versions of themselves, sitting next to each other on an airplane in a world that appears to be our normal Earth.
** Our Earth plays a greater role in the ''Science of Discworld'' series, where the wizards know it as "Roundworld".
** Moreover, the existence of alternate worlds (i.e. different legs of the Trousers of Time) is a given in several Literature/{{Discworld}} novels. Granny Weatherwax starts picking up random memories from these alternate worlds in ''Lords and Ladies'', and Sam Vimes accidentally ''swaps P.D.A.s'' with his [[spoiler: ill-fated]] counterpart from an alternate world in ''Jingo''.
** Also in ''Lords and Ladies'' Ponder Stibbons (a wizard version of a physicist) tries to explain the "many worlds'' principle to the Archchancellor (chief Wizard). Of course this goes badly as the Archchancellor is mainly concerned about why his trousers have anything to do with it, and why his parallel self never sent him a wedding invite...
* Creator/IsaacAsimov's ''Literature/TheGodsThemselves'' is about the discovery of a way to transport materials from our universe to another one[[note]]Or rather, aliens from the other Universe discovered the technology, and began sending us materials in the hope that we'd figure out what was going on and exploit it[[/note]] where the Laws of Physics operate slightly differently than they do here. The practical upshot of this is that the difference in physical law can be harnessed to create free, unlimited power. [[spoiler: It's eventually discovered that continued use of this power source will result in the Solar System collapsing into a quasar. Worse yet, the aliens from the other dimension who created this transdimensional transportation technology are fully aware of this, and are taking advantage of our desire for free energy to prolong the life of their own star.]]
* ''Literature/HisDarkMaterials'' features many an AlternateUniverse, with a few powerful items allowing one to travel between them. There may be no limit to the number of separate worlds and universes.
* The core premise of the ''Literature/LafayetteOLeary'' series. In ''The Time Bender'', O'Leary finds himself transported to the kingdom of Artesia in an alternate universe. In ''The World Shuffler'', he is transported to another world, Melange, which is a close parallel to Artesia, and even has alternate versions of several of the people he knows from Artesia, including his wife.
* From a collaboration of Creator/TerryPratchett and Creator/StephenBaxter, the titular ''[[Literature/TheLongEarth Long Earth]]'' is a series of alternate earths, each different, though the amount and type of difference between one and the next varies. Because of peculiarities of evolution, only one earth spawned humans and the vast majority never developed intelligent hominids of any kind, leaving the whole set in the care of one earth's-worth of humans, and their alternate-universe cousins, named after common fairy-tale creatures like elves and trolls. There are two unique wrinkles in the alternate-earth system presented in this series:\\
Firstly, the earths are linked in a chain, and you can only "step" from one earth to one of the two adjacent ones; even stepping at high speed, it takes quite a while to get from one earth to a radically different one, although there are short-cuts that make long-distance "travel" more feasible. The chain might be infinite, or might be a closed loop. Secondly, each planet has its own chain of alternates; if you go to Mars, as occurs in the third book, none of the alternate Marses you can step to will correlate with any alternate earths in the chain you came from.
* The trope's name comes from Creator/MichaelMoorcock's books. His many books range a vast array of worlds yet a sizable proportion of them are connected via CanonWelding. Creator/RobertAHeinlein used this name in ''Literature/TheNumberOfTheBeast'' (see below) as well.
* Introduced as the Whole Sort of General Mish-Mash in ''Literature/MostlyHarmless''. As explained, any random slice of the Mish-Mash, at any angle, is seen by the inhabitants a functional 4-dimensional universe. This means that parallel universes [[MindScrew a) aren't parallel, and b) aren't universes]].
* ''Literature/TheChroniclesOfNarnia'' mainly feature travel to and from Narnia, but in ''Literature/TheMagiciansNephew'' it's explained that our world and Narnia are only two of a Multiverse of worlds. We only ever see three, though. Five, if you count the Wood Between the Worlds, and [[spoiler:Heaven, although this it is portrayed as being as clearly and obviously different from the rest as a cube is from a square]].
* The entire point of the ''Paratime'' series by Creator/HBeamPiper was that the main character's culture had exhausted its resources and was sponging off ''the entire Multiverse''.
* ''Literature/PerryRhodan'' is explicitly set in a multiverse, but deliberate travel between different universes isn't easy or necessarily safe. Problems involve the (at Galactic tech levels) largely unsolved issue of trans-universal navigation and the problem of adapting to the new physical laws of the destination, which has resulted in "strangeness shock" rendering entire starship crews comatose for months on arrival in the past. The focus of the action thus remains on the default 'main' universe, though interaction with others (including one in which time runs much more slowly, one that consists entirely of antimatter, and one that was and presumably still is heading for an artificially accelerated 'big crunch') has occurred in the past.
* The Quantum Enchantment trilogy and its sequel by Kim Falconer uses the 'many-worlds' concept as a plot device. Working from memory, there is a dystopian Earth a few hundred years in the future, and a completely separate world where magic and the like are common place. Throughout the series, the characters manage to get themselves lost in the 'corridors' between the worlds, often returning to what would be their home but for some sort of twist -- a battle was won instead of lost, time flows in a different direction, person X never existed. It gets somewhat confusing after a while.
* ''Literature/TheRiftwarCycle'', by Creator/RaymondEFeist involved several universes with magical travel between them. It's always dangerous though, because opening a hole in your universe may attract the attention of beings who were (barely) defeated once by ''gods''...
* Creator/RobertAHeinlein has written about Multiverses more than once. The novel ''Literature/GloryRoad'' has magical inter-universe travel, and several of his later novels (starting with ''Literature/TheNumberOfTheBeast'') involve the Burroughs drive, an invention that lets you travel to other universes; but because of how the Multiverse works, those nearby universes will be the favorite fictions of the users of the drive. So you can leave Earth and the next universe over will turn out to be Oz... As a side effect, Heinlein managed [[CanonWelding to tie together]] practically everything he ever wrote into a single setting.
* Creator/SergeyLukyanenko's ''Literature/RoughDraft''-''Final Draft'' duology is set in a multiverse where travel between universes is accomplished using the seemingly magical Towers [[spoiler: which in reality were created through highly advanced technology developed by the natives of a universe that suffered a devastating nuclear war]]. It's initially assumed that there are about a dozen worlds, but it's later revealed that the number is much higher, possible infinite.
* VasiliGolovachov's ''The Saviors of the Fan'' duology (made up of ''The Envoy'' and ''The Deliverer'') has a myriad parallel worlds some of which are similar to ours, while others vary wildly. And that's just those organized into a linked structure called the Worldfan, of which our world is a part, with the implication that there are countless other worlds. According to the protagonist's half-Japanese friend, some of these worlds may be familiar from folk tales or science fiction/fantasy novels, as information has a tendency to "leak" between the worlds, meaning all those stories are actually true in other worlds. There is a world where the mere act of moving alters the surrounding reality (making finding your way back extremely difficult), or a world made up of a gigantic tree.
* The setting of ''[[Literature/{{Somewhither}} A Tale of the Unwithering Realm]]''. Each version of Earth (called an "Aeon") in the Multiverse is an Earth where some Christian miracle never happened, which turns out to have major consequences, as each Earth is inhabited by [[AllMythsAreTrue various beings from mythology]]. The world of Cainem is one where humans were never exiled from Eden, and thus all are immortal ([[WhoWantsToLiveForever and not enjoying it at all]]); Thalassa is a world where Noah's flood never ended, and so it's inhabited by mermaids; Sidon is where David failed to kill Goliath, who begat a race of giants, and so on. The main villains, the empire of [[EvilTowerOfOminousness the Dark Tower]], come from Ur, where the construction of the Tower of Babel was succesfully completed.
* The world of ''Literature/TheTraitorSonCycle'' is eventually revealed to be only one of multitude of "spheres", each sphere being its own universe. Various Wild creaures - as well as, apparently, humans - have arrived in it from other worlds, and [[spoiler:the PowersThatBe are fighting over this sphere because it contains gates that lead to seven others.]]
* Sharon Farber's "Trans Dimensional Imports" (1980). Contact between universes is difficult because the necessary equipment has to be operating in both at the same time, but one scientist has succeeded in contacting her alternate self. They've build a minor business, trading literary works that exist in one world but not the other. With expanded bandwidth, they're considering other art forms. E.g. in one universe, UsefulNotes/RonaldReagan went into politics, becoming governor of California. In the other, he had starred in a B-movie called ''Film/{{Casablanca}}''. So they agree to a swap -- "You get a classic; we get a joke."
* ''Literature/{{Transition}}'' by Iain Banks
* In ''Literature/TheWheelOfTime'', there is a multitude of possible other 'verses, called the 'Worlds That Might Be', which are basically {{Alternate Universe}}s. The less likely they are, the more faded they look. A channeler can be transported to one of these by using a Portal Stone and the One Power.
* Creator/AndreyLivadny has decided to link his LongRunningBookSeries ''Literature/TheHistoryOfTheGalaxy'' with several other works in order to create a new setting called ''The History of Worlds'', which features five distinct parallel realities that make contact with one another. Each of those worlds has humanity go through radically different histories and, possibly, meet different alien races (apparently, humans are the only race that exists in all five realities). In one world (''The History of the Galaxy'' universe), humanity has spread out into the galaxy, settling hundreds of worlds and encountering half a dozen alien races. In another world (''Another Mind'' universe), humanity is still at the level of development of the early 21st century, when it comes under alien attack. In the ''Life Form'' universe, humans are busy settling the Solar System, planning to explore the galaxy using STL ships, when alien artifacts are discovered on some of the planets. In the ''Contact'' universe, humanity is exploring the stars using hyperspace with Earth becoming a CityPlanet and [=AIs=] everywhere. Then an archaeological dig on Ganymede finds evidence of multiple alien races. Finally, in the Omni universe, Earth is a radioactive wasteland following a mutually-destructive war between humans and InsectoidAliens, whose homeworld was destroyed in retaliation for them nuking Earth. The remains of both races struggle to survive, while another race schemes to end them.

[[folder:Live-Action TV]]
* Frequently a DiscussedTrope on ''Series/TheBigBangTheory''.
--> '''Penny''': What's a Multiverse?
-->''' Sheldon''': GET HER OUT OF HERE!
* ''Series/CharlieJade'': the Alphaverse (a CrapsackWorld ''and'' a {{Dystopia}}) is running out of clean water from its excessive pollution. So they use a portal to steal water from the [[{{Utopia}} utopian]] Gammaverse. Charlie Jade ends up in the world in between -- the Betaverse, a.k.a. our world -- when things go wrong with the portal. Later on he finds out that the hallucinations he's had through his life are actually [[spoiler:the result of his ability to travel between the verses]], and he returns home before deciding he liked the Betaverse better than Alphaverse. Long story short, the whole series is based around this trope, including the cliffhanger season finale (from which the show didn't get renewed) that would have revealed a ''fourth'' universe.
* ''Series/{{Community}}'' delved into the multiverse in Episode three, season three "Remedial Chaos Theory" where Jeff decides to roll a die in order to decide who has to get up to collect the pizza; in doing so, he creates six different timelines with vastly different outcomes. The die returns in the final episode of season four where they each face off with the victims of the die's worst timeline, the gang's "evil counterparts."
* ''Series/DoctorWho'' is a bit tricky. There are alternate timeline-style universes, like the fascist universe of ''Inferno'', or Pete's World from "Rise of the Cybermen"/"The Age of Steel"; post-the Last Great Time War, it's potentially multiverse-destabilising for a TARDIS to hop between such universes. There are also pocket dimensions linked to the main universe, such as E-Space or the Land of Fiction.
* ''Series/TheFlash2014'' introduced the idea of a DC multiverse, which can be viewed whenever Barry travels from one universe to another. So far, there is no official name for this multiverse, but the Earths known to exist in that multiverse include:
** [[Series/{{Arrowverse}} The Arrowverse]], named after the universe that began with an adaptation of [[ComicBook/GreenArrow The Green Arrow]]'s origin story. In-Universe, it was given the nickname of '''Earth-1'''. ''That'' universe contains:
*** ''Series/{{Arrow}}''
*** ''Series/TheFlash2014''
*** ''WesternAnimation/{{Vixen}}''
*** ''Series/{{Constantine}}''
*** ''Series/LegendsOfTomorrow''
** '''Earth-2''' is another universe, and was connected to Earth-1 in a freak accident involving a wormhole. It appeared prominently in [[Series/TheFlash2014 season two of The Flash]] and has been visited by various characters of Earth-1 and Earth-3 several times.
** '''Earth-3''', first mentioned in the ''Flash'' season 2 finale and briefly visited in season 3. This is where [[spoiler: the real Jay Garrick]] is from.
** ''Series/{{Supergirl 2015}}'' has its own Earth, '''Earth-38''', which has been visited by the Barry Allen of Earth-1 twice.
** ''Series/TheFlash1990'' is [[Recap/TheFlash2014S2E13WelcomeToEarthTwo also confirmed]] to have its own Earth '''(number unknown)''' within the multiverse, where the conceit of this Earth is "What if superheroes were active in the 1990s instead of the 2010s?" This Earth is identical to Earth-1, but several events and incidents from Earth-1 (especially ''Series/TheFlash2014'') are depicted with the influence from a Barry Allen active as the Flash in the 1990s instead of the 2010s. Barry Allen from Earth-1 has briefly glimpsed this universe, but has not visited it yet. [[spoiler: [[Recap/TheFlash2014S3E9ThePresent One episode]] from the 2014 series of The Flash strongly implies that this Earth is actually Earth-3, but it has been unconfirmed]].
** '''Earth-19''' is where Harrison "H.R." Wells is from. Apparently, that world has been invaded by another Earth at some point (the invasion was repelled at great cost), resulting in laws that punish attempts to travel to or from Earth-19 with death. The only ones allowed to travel this way are Collectors, whose job is to track down and capture violators. This world's Flash appears to be the Accelerated Man.
** Notably, at least two of the same alien races exist in both Earth-1 and Earth-38: Dominators (they invade Earth-1 in a crossover event and one is seen in ''Series/{{Supergirl}}'') and Thanagarians (mentioned in both ''Series/LegendsOfTomorrow'' and ''Series/{{Supergirl}}'').
** Another interesting fact about this multiverse is that temporal changes on one Earth don't affect others, even if there were interactions between them. This comes to light, when Harry and Jesse return to post-Flashpoint Earth-1 and start noticing differences from what they remember during their last visit.
** Little is known about '''Earth-12''', except that it's home to [[HerrDoktor Herr Harrison Wolfgang Wells]], who appears to be a cross between "Harry" Wells and Creator/SteveJobs.
** Likewise, we're not told much about '''Earth-47''', but its H. Lothario Wells is a "genius, billionaire, playboy philanthropist" with a dash of [[Magazine/{{Playboy}} Hugh Heffner]].
** '''Earth-22''' is a post-apocalyptic wasteland that appears to be a mix of ''Film/MadMax'' and ''VideoGame/{{Fallout}}'', with Wells 2.0 being an Aussie cyborg.
** It's eventually revealed that the number of Earths is finite - [[ArcNumber 52]] to be exact. Well, 53, actually, but nobody wants to talk about '''Earth-X''', as it's a world where the Nazis won World War II. This is primarily where ''WesternAnimation/FreedomFightersTheRay'' is set, although the protagonist is actually from Earth-1.
** '''Earth-15''' is offhandedly mentioned to be a lifeless world.
* In the middle of the first season, ''Series/{{Fringe}}'' suggests a multiverse through the ZFT Manifesto. In the season finale [[spoiler: Olivia goes there and meets Walter's old partner William Bell--in his office in the Alternative World's still-standing World Trade Center]].
** The Alternative Universe is further explored in Seasons 3 and 4, as both universes first suspect each other of trying to destroy the other and then team up to fight a common enemy. Two possible futures of the Prime Universe incorporated similar conditions as the Alternate Universe, in keeping with the idea that the evolution and decay of the Alternate Universe was slightly ahead of the Prime Universe. The show conveniently applied a red/blue color scheme to differentiate the "Red-Verse" and "Blue-Verse." The most prominent difference is the color of the Statue of Liberty: green in Prime and bronze in Alternate. This was frequently used to show which universe was being shown.
* ''Franchise/KamenRider'' is an odd handling of this: The Showa era shows all seem to take place in the same world, since veteran Riders would show up to help out the new guys, while the Heisei era shows all seem to be their own self-contained universe[[note]]Though ''Series/KamenRiderAgito'' is a little confusing; check its page for details[[/note]]. Then along comes ''Series/KamenRiderDecade'', which portrays every series as its own separate universe, with their own {{Alternate Universe}}s. In the final episode, a villain forcibly merges the universes together, then in the GrandFinale movie Decade performs a HeroicSacrifice to preserve the memories of the Riders, and from that point on all Riders seem to exist in a shared universe as evidenced by the annual crossovers, not to mention the ''Super Hero Taisen'' movies where the Riders team up with the Franchise/SuperSentai and Franchise/MetalHeroes.
* In ''{{Series/Lexx}}'' there are only the Light Universe and the Dark Zone. And the Dream Zone. And the Other Zone.
* ''Series/OnceUponATime'' and ''Series/OnceUponATimeInWonderland'': Most of ''OUAT'' takes place in Storybrooke, a town created by magic that exists in the Land Without Magic, which is our "real world". The curse that created Storybrooke also trapped many people from The Enchanted Forest there, characters from various fairy tales and other stories. Other worlds include [[Literature/PeterPan Neverland]], [[Literature/AlicesAdventuresInWonderland Wonderland]] (in which SpinOff series ''Once Upon a Time in Wonderland'' takes place), [[Franchise/TheWizardOfOz Oz]], the Land Without Color (a DeliberatelyMonochrome world where Dr. Literature/{{Frankenstein}} is from), a [[UsefulNotes/VictorianBritain Victorian England]] where Alice is from, a [[TheRoaringTwenties 1920s England]] where Cruella de Vil is from, TheUnderworld, The Land of Untold Stories (a universe that serves as a dumping ground for characters from stories that never finished), the Wish!Universe (a genie-created reality where Regina was defeated before casting the Dark Curse), and the Dark Realm (domain of the [[GreaterScopeVillain Black Fairy]]). Then Season 7 further complicates things by revealing that there are variations on the Enchanted Forest, to reflect the different versions of the stories told in our world.
* ''Series/RedDwarf'' has an infinite number of parallel universes, and our heroes have crossed over occasionally:
** "Parallel Universe" features a dimension where everyone throughout history is gender-flipped.
** "Dimension Jump" introduces Ace Rimmer, Rimmer's counterpart from a dimension where he actually successfully became a Space Corps test pilot [[spoiler:after being held back a year in primary school and resolving to do better]]. An alternate Lister also appears in the same dimension, here a flight engineer who is married to Kristine Kochanski.
** "Stoke Me A Clipper" brings back Ace, who has since become a sort of dimension-hopping superhero (and a [[spoiler:LegacyCharacter, with enough predecessors for their coffins to form an entire planetary ring]]). We see him in one dimension rescuing the Princess Bonjella from Nazis.
** "Ouroboros" introduces Kristine Kochanski as a new cast member, originally hailing from an alternate universe where she was the sole survivor of the radiation leak that wiped out the crew instead of Lister.
* The TV show ''Series/{{Sliders}}'' did this, although the heroes had no control over where they ended up each week.
* In Season 1 Episdode 10 of ''Series/{{Shadowhunters}}'' Clary travels to an alternate universe where Shadowhunters defeated demons hundreds of years ago, causing there to be no need for them, while downworlders went into hiding to blend in with Mundane's. Clary and all her Shadowhunter friends ended up growing up with Mundane lives.
* Kirk, [=McCoy=], and several others were transported to a MirrorUniverse in the "Mirror, Mirror" episode of the original ''Series/{{Star Trek|The Original Series}},'' in which a dark Earth-based empire ruled the galaxy. This was very much an InSpiteOfANail universe, since everything was much the same except the moral/ethical bent of the Federation's counterpart and its citizens.
** Years later, the cast of ''Series/StarTrekDeepSpaceNine'' returned to this universe to discover that the revolution Kirk had encouraged its native Spock to foment had happened; unfortunately, its effects were not necessarily for the better.
** ''Series/StarTrekEnterprise'' revisited this again in "In a Mirror, Darkly", just to hammer it home that HumansAreBastards.
*** ''Series/StarTrekTheNextGeneration'' had an episode with Worf bouncing between various InSpiteOfANail alternate universes. According to WordOfGod, this is distinct from the usual MirrorUniverse though.
*** The showrunners of the new TOS-based movie series cite this episode, suggesting that the new Franchise/TrekVerse exists alongside, rather than replacing, the old one. The ExpandedUniverse definitely embraces this (stories in the old Franchise/TrekVerse continue to be told rather than ''everything'' having to be based on ''Film/StarTrek'' and ''Film/StarTrekIntoDarkness'' only. Stories unrelated to the new movies' events might reference the mysterious disappearance of a certain famous Vulcan in passing.)
* ''Series/StargateSG1'' had a handful of episodes where characters traveled to alternate timelines. The first season finale's storyline was kicked off when Daniel accidentally activated an [[AppliedPhlebotinum alien artifact]] and went to a timeline where he had never joined the Stargate program. A later episode used the same artifact to help an Earth in an alternate timeline that was faced with looming invasion, and other ways of accessing alternate universes were later found as well.
** The season 9 episode "Ripple Effect" turned this UpToEleven, with dozens of alternate universe versions of SG-1 coming through the Stargate due to some technobabble involving a black hole (and the meddling of one of the alternate teams.)
** ''Series/StargateAtlantis'' also has several episodes that make use of the multiverse. The first has [[spoiler:[=McKay=]'s sister]] write an equation that allows connections to alternate universes to be made. [=McKay=] uses it to try to make an unlimited power source. [[spoiler:The [=McKay=] from the universe he connected to]] has to cross the barrier to tell him it's a bad idea. The same technology was later used by [=McKay=]'s rival back on earth to try to combat global warming [[spoiler:(it didn't work)]]. And yet another [=McKay=] from a different universe uses the same technology to build a Universe Hopping Starship [[spoiler:(again, it didn't work)]] which sent the team from this universe on a wild ride. One just has to wonder if [=McKay=] really knows what he's doing when it comes to the multiverse.
* ''Series/{{Supernatural}}'': Not only is there a Heaven, Hell, and Purgatory aside from Earth, but there are also multiple alternate realities, including one where the Winchesters' life is a TV show, one where the Apocalypse wasn't stopped in time, and one populated entirely by monsters.
* In ''Series/ThirdRockFromTheSun'' there is a two part episode where the aliens visit an alternate universe (because they are bored) where they settled in New York instead of Ohio.
-->'''Dick''': You may see people you know too. But FYI they may have made different life choices.\\
'''Harry''': I see, in this universe Officer Don could be an old Vietnamese woman.\\
'''Sally''': No Harry, they have the same bodies. Dick is saying they'll all probably be gay.

[[folder: Mythology]]
* Myth/NorseMythology presents a cosmology of Nine Worlds, connected by a gigantic WorldTree. This would include Asgard (where the gods live) and Midgard (Earth), but unfortunately we haven't found a definitive list of them, and piecing it together from what we ''do'' know has proven tricky (are Niflheim and Helheim the same place? What about Nidavellir and Svartalfheim? And what's up with Andlang and Vethrfolnir?)

* In the first episode radio series ''Radio/{{Undone}}'', Edna Turner discovers that she is able move between London, and its parallel city Undone, where weirdness leaks from. Slowly, she finds she is able to cross to over to other versions of London - such as Donlon, Londinium, Londres, and Lahndan (said in an over-pronounced cockney accent). Her job becomes to maintain the balance between the worlds, discovers her sister, and finds that they seem to be the only people who do not have parallel versions.

[[folder:Tabletop Games]]
* The ''TabletopGame/{{GURPS}}'' supplement ''TabletopGame/InfiniteWorlds'' provides a setting and mechanisms for not only setting up a Multiverse incorporating all other ''GURPS'' books as a background against which to play, but also providing an interdimensional cold war as a driving force behind a potential campaign.
* The trading card game ''TabletopGame/MagicTheGathering'' is set in a multiverse, with each expansion set representing a new universe (well, mostly). The game also implies that the players represent Planeswalkers, mages able to travel from one universe to the next essentially at will. The cards played represent magic and land discovered while exploring a given universe.
** The casual variant Planechase literally represents the planeswalking with plane cards that affect gameplay and get cycled in and out as players shift to new worlds.
* ''TabletopGame/{{Planescape}}'', and by extension, the computer game ''VideoGame/PlanescapeTorment''.
** And, through further extension, the whole of ''TabletopGame/DungeonsAndDragons'', though there are no or few crossovers between different game settings, such as TabletopGame/{{Eberron}} showing up in the Forgotten Realms.
*** ''TabletopGame/{{Spelljammer}}'' originally combined ''Greyhawk, TabletopGame/{{Dragonlance}},'' and ''Forgotten Realms,'' though like ''TabletopGame/{{Planescape}}'' it can be extended to other settings that don't explicitly say their world isn't in a crystal sphere. The other planes of existence are only accessible from within the crystal spheres however. The Phlogiston that makes up the bulk of the Prime Material Plane is cut off from the planes.
*** ''Planescape'' in fact explicitly includes the ''Spelljammer'' setting as part of its multiverse, along with all the aforementioned settings, as well as ''Birthright'', ''Ravenloft'' and implicitly every D&D setting ever devised, including contradictory ones.
*** TabletopGame/{{Ravenloft}} is yet another setting that could bridge the divide between different D&D settings, including otherwise-inaccessible ones like Mystara, Athas, or Gothic Earth.
* ''TabletopGame/{{Rifts}}'' is part of Creator/PalladiumBooks' "Megaverse", which includes all of its other games (naturally), plus a number of other realms with some of the games. The Rifts themselves are tears in the fabric of reality that have turned Earth into a sort of interdimensional hub which can connect to any and every other part of the Megaverse.
* Naturally part of the setting of ''TabletopGame/SentinelsOfTheMultiverse''. The final expansion of the game deals with the end of that multiverse (according to WordOfGod, this is why the sequel game, ''Sentinels Tactics'', doesn't include the word), and will see the heroes teaming up with alternate-universe versions of characters to stop an omnicidal BigBad.
* ''TabletopGame/{{Torg}}'' deals with the invasion of Earth by several different realities (cleverly typified as various classic roleplaying genres), each of which is trying to change our local reality axioms to be like their own.
* Creator/WizardsOfTheCoast long ago published a set of generic supplements for handling deities in roleplaying games, called ''The Primal Order''. One of the books in this series, ''Chessboards'', covered in exquisite detail how to design and manage an entire multiverse complete with cosmology.

[[folder:Theme Parks]]
* At Ride/UniversalStudios:
** ''Ride/TheFuntasticWorldOfHannaBarbera'' featured each Hanna-Barbera cartoon being set in its own world that can be entered by a portal.
** ''Ride/JimmyNeutronsNicktoonBlast'' appears to be set in one, with the different Nicktoon worlds being accessible via soundstage portal.

* ''Toys/{{BIONICLE}}'':
** During the Karda Nui arc, a TeleporterAccident sends Takanuva to an AlternateUniverse instead of Karda Nui. He spends the majority of his screentime traversing various Alternate Universes, until finally making it to his intended destination. Other characters, such as Vezon and Mazeka, also explore Alternate Universes in a similar manner.
** A subplot featuring an alternate, benevolent version of the BigBad crossing over into the main universe was set up during the same arc, but due to BIONICLE's abrupt cancellation, it ended up an AbortedArc.
* ''Franchise/{{Transformers}}'' has a whole pile of alternate universes which sometimes cross over, and which [[FlipFlopOfGod Hasbro and Takara disagree over]] which are actually separate and which simply occur to the side of other stories. The Transformers of the [[ComicBook/TransformersTransTech Axiom Nexus]] have grouped all continuities into a number of [[http://tfwiki.net/wiki/Universal_stream universal streams]], with each stream corresponding to a continuity group. Thus, for example, Primax is the G1/Beast Era family, Tyran is the live-action movies, Gargent is the [[WesternAnimation/ChallengeOfTheGobots GoBots]], [[FourthWall Quadwal]] is the [[RealLife real world]], etc. Some of these are [[MirrorUniverse negative-polarity universes]] in which Decepticons are good and Autobots are evil; these are assigned negative numbers. To make things ''really'' nuts, there are also characters known as multiversal singularities, of which only one exists in all reality. Some of these, such as Alpha Trion, exist in every universe simultaneously, while others, like Vector Prime and The Fallen, travel between universes. There are also [[OurSoulsAreDifferent sparks]] that resonate across the universe, giving rise to multiple similar but separate versions of Optimus Prime, Megatron, Starscream, and various others.
** It should be noted that this is AllThereInTheManual. There's no sign in any of the televised series or available-at-your-comics-shop comic books[[note]] Aside from Fun Publications' ''Franchise/TransformersTimelines'', which do receive limited direct market print runs[[/note]] -- that is, any canonical stories -- that you could "[[Series/{{Sliders}} slide]]" from ''Anime/TransformersArmada'' into ''WesternAnimation/TransformersAnimated,'' despite years of "collector's club" and convention exclusive materials that suggest you can. Fingers are still crossed around the fandom for a ''WesternAnimation/TurtlesForever'' sort of project someday, somehow.
** The Franchise/TransformersAlignedUniverse, which includes ''WesternAnimation/TransformersPrime'', ''WesternAnimation/TransformersRescueBots'', the ''[[VideoGame/TransformersWarForCybertron War for Cybertron]]'' video game series and the novels retelling the narrative of the games, are was originally considered to be outside this multiverse. However, Hasbro has since reversed this with works like ''VideoGame/TransformersRiseOfTheDarkSpark'' and ''[[AllThereInTheManual The Complete]] [[WesternAnimation/TransformersAnimated AllSpark Almanac]]'', and it's been revealed to be part of the larger Transformers multiverse, after all.
** An event called [[http://tfwiki.net/wiki/Shroud "the Shrouding"]] altered the nature of the Transformers multiverse, doing away with the concept of multiversal singularities and greatly strengthening the boundaries between dimensions.
** The Facebook incarnation of [[FourthWallMailSlot "Ask Vector Prime"]] notes that the Multiverse can occasionally interact with a larger Megaverse, and beyond that is the Omniverse, which consists of every reality imaginable, as well as some that aren't. (Admittedly, it's a bit more complicated than that, but that's the basic gist.)

[[folder:Video Games]]
* ''VideoGame/{{Anachronox}}'' takes place in one universe but [[spoiler:deals with the universe before this one and the universe after this one]]; if there was a second game, we would have [[SanDimasTime gone to the former]]. Plot: [[spoiler:In the next universe, two forces -- "Chaos" and "Order" -- are pitted against one another for survival. Order managed to trapped Chaos in this universe. Chaos is trying to find a natural doorway into the previous universe where it seeks to destroy this universe and the next universe, and Order in the process.]]
* In ''VideoGame/BioShockInfinite'', Elizabeth is able to open "tears" in the fabric of reality, which are open windows to parallel realities. One example is a 1980s street in front of a cinema where ''[[Film/ReturnOfTheJedi Revenge of the Jedi]]'' is played.
** [[spoiler:This goes UpToEleven by the ending, where it's shown there is an infinite amount of different dimensions, each of them being linked by the fact of having a man (Booker, Jack), a lighthouse and a city (Rapture, Columbia).]]
** One of the [[spoiler: Elizabeths in the ending is the beta model used in the early gameplay demos.]] This means that all of the DummiedOut content like Saltonstall and the incidents like saving the mailman from the Vox Populi could be a sort of quasi-canon, taking place in alternate versions of Columbia with alternate Bookers.
* Past a certain point in the game, it is quickly discovered that this is the case in ''VideoGame/BravelyDefault''. [[spoiler:At the start of Chapter 5, the heroes initially think they're in a GroundhogDayLoop, but discount this theory as more and more discrepancies arise thanks to differences in each individual world.]]
* ''VideoGame/CityOfHeroes'' has Portal Corp., a company dedicated to exploring other dimensions. There are several individual missions and arcs where you get to deal with hostile other-dimensional entities, either after they've entered Paragon or at their source. The current state of the CityOfAdventure can be traced back to a massive invasion from AnotherDimension.
** One such alternate dimension, Praetoria, is the focus of the latest expansion, ''Going Rogue'', which fleshes out that dimension beyond CrapsackWorld MirrorUniverse by adding moral complexity and considerably more shades of grey.
* ''VideoGame/EternalDarkness'': After beating the game under all 3 ancients you find out that the other ancients (the ones that you beat in the previous two playthroughs) [[spoiler:were killed by the main character's counterparts in other, parallel universes. Mantorok then overlaps the three realities, killing all three ancients concurrently and leaving the universe free of them forever.]]
* ''Franchise/FinalFantasy'' in general is strongly hinted to take place in a multiverse, with each game (barring a couple exceptions like direct sequels that take place in the same world) taking place in parallel universes. It hasn't been officially confirmed, but every Final Fantasy game has its own version of Cid, Biggs, Wedge, Chocobos, summons (Ifrit, Leviathan, Bahamut, etc), and the worlds they take place in seem to be similar, and yet different at the same time.
** Though not officially stated, the Rift from ''VideoGame/FinalFantasyV'' seems to be a wall separating all the various universes of the ''Final Fantasy'' games. Only Gilgamesh has been shown to be able to get around it freely so far. After his banishment there by Exdeath, and his subsequent HeroicSacrifice against Necrophobe, [[DimensionalTraveler he sets off on a quest]] to collect rare weapons, appearing in the worlds of ''Final Fantasies'' ''[[VideoGame/FinalFantasyI I]]'' (remake), ''[[VideoGame/FinalFantasyIVTheAfterYears IV]]'', ''[[VideoGame/FinalFantasyVI VI]]'' (remake), ''[[VideoGame/FinalFantasyVIII VIII]]'', ''[[VideoGame/FinalFantasyIX IX]]'', ''[[VideoGame/FinalFantasyXII XII]]'', and ''[[VideoGame/FinalFantasyXIV XIV]]''. At some point, he also manages to find his way into [[VideoGame/DissidiaFinalFantasy the conflict between the gods Cosmos and Chaos]], and is overjoyed to find Bartz there, having been itching to get a rematch against him. Unfortunately, Bartz has only the faintest of memories of his home world in this continuity, making ol' Gilgamesh an UnknownRival to him.
** Eorzia, the world of ''VideoGame/FinalFantasyXIV'', seems to be a veritable hotspot for wanderers through the multiverse to wind up, so far we have Gilgamesh (naturally), [[VideoGame/FinalFantasyXIII Lighting]], [[VideoGame/FinalFantasyXI Shantotto]], [[VideoGame/DragonQuestX Brick Golems]], and [[VideoGame/FinalFantasyXI Iroha]]. For the most part they have no actual bearing on the plot and may not be canon, but Iroha at least seems to be sticking around instead of returning to her [[spoiler:[[ApocalypseHow non-existent]] alternate timeline on Vana'diel]].
** Even locations seem to have alternate versions as the two Crystal Towers of ''VideoGame/FinalFantasyIII'' and ''VideoGame/FinalFantasyXIV'' show.
* It was thought that the different ''Franchise/FireEmblem'' verses all took place on separate worlds (the [[VideoGame/FireEmblemAkaneia Akaneia]] and [[VideoGame/FireEmblemJugdral Jugdral]] games and ''[[VideoGame/FireEmblemGaiden Gaiden]]'' aside), until ''VideoGame/FireEmblemAwakening'' came along and introduced the concept of the Outrealm Gates linking different worlds together. In fact, it's also implied (particularly in ''Awakening''[='s=] "The Future Past" DLC) that [[spoiler:the TimeTravel present in ''Awakening''[='s=] main plot isn't really so much time traveling as much as it is dimension hopping]], further implying that ''every single playthrough'' of each game is equally canon.
* ''VideoGame/{{Injustice 2}}'' features the Multiverse, both as a story element and gameplay feature.
** In the story, Doctor Fate had saved Black Canary from being killed by the Regime by transporting her into an alternate dimension, where she met and eventually married a version of Green Arrow whose own universe's version of Black Canary had died.
** The Multiverse is featured as a gameplay mode: presented as Batman's "Brother Eye" surveillance network monitoring dimensional anomalies created in the wake of Batman having summoned an alternate universe's heroes in [[VideoGame/InjusticeGodsAmongUs the previous game]]. In a similar vein to the Living Towers of ''VideoGame/MortalKombatX'', parallel Earths in this game's Multiverse mode change from hour by hour, day by day, and week by week, offering different rewards for saving them.
* ''Franchise/KingdomHearts'' indulges in this concept with the Worlds; separated by near-impenetrable barriers (unless you can find a way to bypass it), but all sharing the same oceans and skies. Unlike most examples, the Worlds seem to be in one universe instead of scattered across infinite dimensions.
* According to WordOfGod, there are at least three timelines in the ''Franchise/TheLegendOfZelda'' series, starting in ''VideoGame/TheLegendOfZeldaOcarinaOfTime''. The Adult Timeline has [[TheHero Link]] defeating [[BigBad Ganondorf]] and returning to the past. The Child Timeline begins when Link completes this trip, allowing him to prevent Ganondorf from coming to power. The Fallen Hero timeline was created by an alternate version of Link [[TheBadGuyWins losing to Ganondorf]]. ''VideoGame/HyruleWarriors'' features a ''fourth'' timeline, where [[BigBad Cia]] opens portals to the other timelines.
* ''VideoGame/MakaiKingdom'' introduced the multiverse concept for the various netherworlds and non-netherworlds introduced by prior Creator/NipponIchi games (prime amongst them ''Franchise/{{Disgaea}}'').
* The ''VideoGame/{{Myst}}'' games (and books) are primarily concerned with a magical means of inter-universe travel (and universe creation, if you believe Gehn).
** In ''VideoGame/MystIIIExile'', Saavedro seems to be capable of annihilating the new D'ni age by destroying the age definition book, so Gehn has a definite point.
*** Later games and novels have explained that destroying the book only destroys the link to that particular world, although since said link can never be recreated, it might as well be considered destroyed as far as travelers are concerned.
*** Furthermore, though official disposal of Linking Books was historically handled with care due to issues of the special techniques involved in forging the world link, there's very little real harm in the action. Much greater harm comes from writing carelessly which can introduce unstable elements into the world described. The original Myst touches on this with Atrus's musings on the Stoneship Age and this is a major problem for the second game ''VideoGame/{{Riven}}''.
* ''VideoGame/TheNamelessMod'' mentions that other forum cities exist, and that travel between them is possible. Apparently a Planet VideoGame/{{Diablo}} merchant is responsible for the mana potions ([[spoiler:that can only be used by a single unique weapon of plot importance]]) being in the game.
* The Franchise/{{Nasuverse}} is actually made of different [[AlternateContinuity different continuities]], possibly because the main works are multi-route visual novels. However, actually ''traversing'' between Universes [[FunctionalMagic is the domain of Magic]] (i.e. a miracle) so only one character can actually do it.
** Also used as a source of infinite {{Mana}} by taking a small amount from an infinite number of alternate realities, using a tool designed by the aforementioned character. Incidentally, this is also a perpetual motion machine since it powers itself.
* ''{{VideoGame/Neptunia}}'' has so far taken place in several alternate dimensions in the mainline games: The [[RetGone retgone'd first game's dimension]] called [[FanNickname the Superdimension]], the current canon [[FanNickname Hyperdimension]] used in ''VideoGame/HyperdimensionNeptuniaMk2'', ''[[VideoGame/HyperdimensionNeptuniaVictory Victory]]'', and ''VideoGame/MegadimensionNeptuniaVII'', the Ultradimension featured in ''[[VideoGame/HyperdimensionNeptuniaVictory Victory]]'', and finally the two new dimensions featured in ''[[VideoGame/MegadimensionNeptuniaVII V II]]'' called the Zero and Heart Dimensions for a total of five. And that's not even getting to the three remakes, the soon-to-be six spinoffs, the manga, and the anime.
* The ''VideoGame/NicktoonsUnite'' series. The world of every Nicktoon show is actually a dimension in the Nicktoon multiverse.
* ''[[VideoGame/PokemonRubyAndSapphire Pokémon Omega Ruby and Alpha Sapphire]]'' reveals in the [[PostEndGameContent Delta Episode]] that there are other ''Franchise/{{Pokemon}}'' realities, like one where Mega Evolution was never discovered ([[ForWantOfANail as a result of]] [[spoiler:AZ's ultimate weapon ''not'' firing three millennia prior to the events of ''[[VideoGame/PokemonXAndY X/Y]]'']]), which is the universe where the original ''Pokémon'' games up to ''[[VideoGame/PokemonBlack2AndWhite2 Black 2 and White 2]]'' take place. This also implies that games like ''VideoGame/PokemonMysteryDungeon'' and ''VideoGame/PokemonRumble'' may be part of the multiverse as well.
** ''VideoGame/PokemonSunAndMoon'' goes a step further in its own post-game subplot. [[spoiler: Salon Maiden Anabel from ''[[VideoGame/PokemonRubyAndSapphire Emerald]]'' appears in an extensive role, only it's heavily implied to be the original, "prime timeline" incarnation of said character. Anabel is established to be a "Faller," a person who has traveled through an Ultra Wormhole due to emitting a strange energy that attracts [[EldritchAbomination Ultra Beasts]], extradimensional Pokémon hailing from [[EldritchLocation Ultra Space]]. This causes Anabel to [[TrappedInAnotherWorld wind up in the "Megaverse"]] with [[LaserGuidedAmnesia few memories of her life in the "Oldverse."]]]]
* In the Perpetual Testing Initiative DLC for ''VideoGame/{{Portal 2}}'', this is the ExcusePlot. Since Aperture Science is bankrupt, all test chamber construction has been outsourced to Apertures in other universes, which is then tested in and stolen back. The DLC comes with new Cave Johnson audio that gives us such gems as Space Prison Warden!Cave, Dark!Cave, and Hobo!Cave.
** As well as a universe filled up entirely with money. Two of them, in fact.
* In ''VideoGame/RatchetAndClank Future: Tools of Destruction'', the all-knowing (for the most part), IRIS Supercomputer mentions that existence is divided into infinite dimensions.
* ''VideoGame/ShinMegamiTenseiIIINocturne'' seems to imply that the various ''Franchise/ShinMegamiTensei'' continuities are all connected through the Amala Universe. ''VideoGame/RaidouKuzunohaVsTheSoullessArmy'' and ''VideoGame/RaidouKuzunohaVsKingAbaddon'' show the existence of the Akarana Corridor, a tunnel linking several times and realities, further confirmed in ''VideoGame/DevilSummonerSoulHackers''. The Yamato Perpetual Reactor in ''VideoGame/ShinMegamiTenseiIV'' links at least three parallel worlds (Firmament Tokyo, Blasted Tokyo, Infernal Tokyo) together through the Reactor Room in Camp Ichigaya.
* The multiverse is a key point to ''VideoGame/SuikodenTierkreis'', though the player/lead PC only technically ever gets to see one (the reason why is also a plot point).
* ''VideoGame/SuperPaperMario'' has this as the plot. Seeing as an OmnicidalManiac is walking about with a [[TomeOfEldritchLore dark book has the future written in it]] [[TheEndOfTheWorldAsWeKnowIt with the way how to end all of existence]], Mario ends at a [[PortalNetwork interdimensional crossroads]] to collect the [[MacGuffin Pure Hearts]].
* ''VideoGame/MarioAndLuigiPaperJam'' reveals that the ''Paper Mario'' games take place in an alternate universe from the ''Mario and Luigi'' games / the rest of the ''Mario'' franchise, accessible through a book in Peach's Castle.
* This trope is a major plot point in ''VideoGame/SuperRobotWarsOriginalGeneration'', with the revelation that the character Gilliam Yeagar is the same character from ''Hero Senki: Project Olympus'', having made his way into multiple {{Alternate Universe}}s to get back to the world of Elpis in ''Hero Senki'', following its events there. The BigBad in ''Original Generation Gaiden'' is implied to be the same BigBad of ''The Great Battle'' series, as well as the creator of Duminuss, the BigBad of ''VideoGame/SuperRobotWarsReversal''.
** Just to give you a clear idea on the "Banpresto Multiverse," ''Original Generation'' is effectively tied into the events of the "[[FanNickname Classic Timeline]]", ''The Great Battle'' series, ''VideoGame/SuperRobotWarsAlpha'', ''Super Hero Sakusen'', ''Reversal'', ''VideoGame/EndlessFrontier'' and ''VideoGame/AnotherCenturysEpisode R''. Due to the [[MassivelyMultiplayerCrossover crossover nature]] of ''Endless Frontier'' into ''VideoGame/NamcoXCapcom'' and ''VideoGame/ProjectXZone'', this implies the multiverse of ''VideoGame/SuperRobotWars'' can potentially be one of the largest in fiction.
** ''VideoGame/SuperRobotWarsZ'' uses this via a [[Anime/SuperDimensionCenturyOrguss Space-Time Oscillation Bomb]] that brings in multiple universes and groups them into one (think ''VideoGame/SuperRobotWars'' [[JustForFun/XMeetsY meets]] ''ComicBook/CrisisOnInfiniteEarths''). Central to ''Z'' are the mysterious artifacts called "Spheres" which allow its holder to travel and summon people between dimensions. The BigBad even summon multiple versions of himself from different dimensions to aid him in the last battle.
* ''VideoGame/{{Touhou}}'' involves quite a bit of world-hopping. Based upon a relatively Buddhist notion of the universe, like the Nippon Ichi example above, with multiple hells (Jigoku) and netherworlds (Makai), it gives the heroines plenty of reason to go ToHellAndBack. This seems to have been more frequent earlier on in the series, when there weren't as many characters, and Gensokyo wasn't as fleshed out. Gensokyo itself seems to be a semi-self-contained world kept vaguely apart from the real/outside world by the Great Hakurei Barrier, in spite of being physically built in Japan. Alternate worlds the heroines may visit include:
** In the original game, ''Highly Responsive To Prayers'', Reimu has to close an [[HellGate open portal to Jigoku / Hell]].
** ''Phantasmagoria of Dim.Dream'' features "scientists" who visit Gensokyo from an alternate dimension in order to "study [[BulletHell danmaku]]" using a "probability hyperdrive vessel".
** ''Lotus Land Story'' has Reimu and Marisa competing to fight their way into the world of dreams, where Kazami Yuuka resides. Reimu and Marisa also visit another dimension that isn't very well explained in the extra stage, just to beat up the creators for no reason at all.
** ''Mystic Square'' features the heroine of the player's choosing invading Makai, the world of demons.
** ''Perfect Cherry Blossom'' features the Netherworld, and Hakugyokuro, land of restless spirits, and effective equivalent of Purgatory. It also has the legendary lost land of Mayohiga, home of the Yakumos.
*** Yukari Yakumo, a RealityWarper, deserves special mention, as her power of "Borders" allows her to generate portals to any other location or dimension she can conceive of. She can even seemingly ''create'' new dimensions, by manipulating the boundary between fantasy and reality, and so make a dream or thought into a real dimension, and then open a portal to it. Needless to say, this makes her a PhysicalGod for all intents and purposes.
** ''Imperishable Night'' has... the Moon. Turns out, there's an extremely different world underneath all that barrenness -- a highly advanced civilization hiding itself from the "impurities" of the Earth. Revisiting the Moon also becomes the objective in ''Silent Sinner in Blue''.
** ''Phantasmagoria of Flower View'' has the Sanzu no Kawa, a mythical, River Styx-like river that separates the land of the living from Higan, the land where the dead wait for their judgment, and, as a result, can wind up in Heaven, Hell, or get reincarnated.
** ''Subterranean Animism'' has the Hell of Blazing Fires lying in the cave networks beneath Gensokyo and the Earth in general, presumably in some sort of vague pocket dimension in the Earth's mantle that only appears in Gensokyo version Earth.
** ''Undefined Fantastic Object'' has Makai (although some debate as to whether it is the same Makai from before, there's some evidence that it is.) Byakuren was sealed within Makai for trying to unite humans and youkai (and getting hordes of racists on her ass), but is released thanks to the result of her followers' actions.

[[folder:Web Animation]]
* In ''WebAnimation/HomestarRunner'', there are a lot of alternate universes. Just to name a few...
'''Peasant Universe'''\\
'''Teenage Universe'''\\
'''Retro Video Game Universe'''\\
'''Sweet Cupping Cakes Universe'''\\
'''Storybook World'''
** In [[http://www.homestarrunner.com/sbemail150.html one Strong Bad Email]], The Cheat builds an alternate universe portal that sends Strong Bad to several of the alternate universes (in other words, a flurry of in-jokes).
** In the fifth episode of ''Strong Bad's Cool Game For Attractive People'', Trogdor manages to escape from the video game universe into Free Country, USA.

[[folder:Web Comics]]
* ''Webcomic/AllOverTheHouse'' is linked to ''The Life of Nob T. Mouse'' via portals and random dimensional jumps. As a result, there are in-universe examples of crossover media, such as ''The Blobland Gang'' stories, which Tesrin of ''All over the house'' read as a child. These are based on Hubert Schlongson's visits to Blob City, which is the main setting of ''Webcomic/TheLifeOfNobTMouse''.
* ''Webcomic/BobAndGeorge'' has a lot of different universes, most of them with completely crazy versions of the characters. (One universe is the universe of the original Japanese Rockman games.)
* Various characters in ''Webcomic/DeviantUniverse'' have appeared from alternate universes, and one story arc involved an attack by another universe.
* French webcomic ''WebComic/DragonBallMultiverse'': An alien race discovers inter-universal travel and gathers the best fighters from every universe to compete in the ultimate tournament. Some of these fighters include a Vegetto that remained fused, a Cell that defeated the Z-Warriors and a Kakarot that didn't lose his memory. The opening few comics imply that the Multiverse is infinite and that the numbers assigned to the various realities are for the sake of the tournament alone. DBZ:M actually goes against tradition by having the "canon" universe receive a moniker other than "One" or "Prime".
* In ''Webcomic/DragonCity'', Erin finds out that her friend Natasha is the alternate universe version of herself, but with brown scales instead of blue. She was temporarily stuck, but when she got back, she found out that she had been declared dead, so spends most of her time in the main universe.
* ''Webcomic/ElGoonishShive'' has a multiverse of worlds sharing many of the same characters. Among them is the main EGS-verse, the Alpha Dimension (where Tedd is a misunderstood Evil Overlord type with a cybernetic hand), the Beta Dimension (where Elliot was born female and Tedd wears square glasses), the Second Life universe (aliens got involved in the American Revolutionary War, Elliot was born as Ellen and went to school with Kaoli), and the less-canon [=AF04=] (April Fools 2004) universe (Tedd was born female, Sara is a goth, and [[spoiler:Susan's dad never cheated on his wife]]).
** And oddly, Tedd is in every universe, something that nobody else can claim. Might be AuthorAppeal or something more considering Shive's love of ChekhovsGun.
* ''Webcomic/TheFarSideOfUtopia'' has referenced the fact that there are multiple dimensions involved -- one organization is called "Interdimensional Security" and travel between the dimensions seems regulated or illegal.
* ''Webcomic/{{Homestuck}}'' has a multiversal setting, with the kids' universe and the trolls' universe playing a major role in the plot. [[spoiler: It's later revealed that Sburb actually ''creates'' new universes that the players can then travel to. Our home universe is the product of the trolls' session.]]
** [[spoiler: Even later, it's revealed that Sburb actually creates ''multiverses''; every possible alternate universe off a base template is encompassed in one Genesis Frog. The sum of all the sessions of Sburb, Genesis Frog multiverses, the Furthest Ring, and the Green Sun is known as Paradox Space]].
* In ''WebComic/{{Jix}}'', Lauren was sent to an alternate dimension where Jix's other personality, Remula, rules Earth.
* ''Webcomic/TheKAMics'' is a multiverse and even has a company that allows travel between alternate universes.
* ''Webcomic/TheLifeOfNobTMouse'' contains a multiverse of sorts through its [[http://www.nobmouse.net/2008/03/31/pie-noon-part-12/ Quantum History]] literary device, where each point in time is a parallel universe that may or may not be attached to any other point in time. Although originally devised as an excuse to get around continuity errors, it allows multiple versions of the main characters to exist at once and have different adventures at the same time.
* ''Webcomic/{{Parallels}}'': Keeping the spaceways safe one universe at a time.
* [[http://amultiverse.com/ Scenes From a Multiverse]], a comic about life in an ordinary multiverse.
* ''Webcomic/SluggyFreelance'' has introduced over a dozen alternate universes by this point, ranging from slightly tweaked versions of the main universe to an endless void outside time to Hell itself.
* ''Webcomic/UltimaJava'' has an interesting example; there are many alternate universes, but each universe has a corridor connecting different worlds within that universe. So, in effect, universes within universes.
* The Webcomic/{{Walkyverse}} has several, but most specifically: the Dargonverse, where Jason's Father's Organization was before it came to the Walkyverse; the [=NoWalkyverse=], where Walky went to college and never joined SEMME; the Dumbiverse, where all of the Walkyverse characters went to the same college and SEMME and aliens don't exist (named for the comic revolving around it, ''Dumbing of Age''), and the ''Webcomic/{{Fans}}'' universe, which is...well...yeah. There's also one where Sal and Danny ended up together and had a kid, and a few others that have gone unnamed.

[[folder:Web Original]]
* The protagonists of ''Script/AHDotComTheSeries'' travel through it in their [[CoolShip Cool Starship]].
* Despite being titled ''Literature/ArcanaMagiUniverse'', the series is a multiverse of five unique worlds, each named after TheFourGods.
* The ''WebVideo/AtopTheFourthWall'' / ''WebVideo/TheSpoonyExperiment'' amalgam seems to have this property, most easily accessed by forcing someone to review some part of the Ultimate Warrior series of comics, which are so awful they break reality. In the course of both sets of reviews, Linkara and Dr. Insano flash through a long series of alternate universes, depicted as female/hippy/plushie/reversed versions of themselves/bad actors/etc. Dr. ''Link''sano purposefully uses this to [[spoiler: gather an army of Insanos -- and it works. Unfortunately they all start fighting each other afterwards.]]
* [[Roleplay/DCUnitedWeStand DC: United We Stand]] is set in one of the many different parts of DC's multiverse.
* ''Literature/DominionAndDuchy'' is explicitly described as taking place in a multiverse. Which is at the centre of multiple multiverses held together by something called the Framework of Reality. The universe the story takes place in holds the object that all the different multiverses orbit around.
** It also implies that there is trade, as in the epilogue, a huge corporation makes a "Dimensional Elevator".
* The heroes of the ''Roleplay/GlobalGuardiansPBEMUniverse'' have discovered a handful of alternate universes with the aid of a dimension-jumping superhuman who calls himself "Pockets", including an Earth where the Confederates won the US civil war, where the Chinese discovered and colonized the west coast of North America in the 1400s, where the Roman Empire lasted until the modern day, and one where the primary difference was that all right-handed people were left-handed, and vice-versa. According to Pockets, you can get used to big changes (like a world where the human race has been replaced by Neanderthals, but all the same individual identities remain), but its hard to get used to the small ones (like the world in which the color blue is called "tralphaz".
* The basis of the Roleplay/GoThroughTheAlphabetBeforeSomebodyPostsAMyLittlePonyPicture Roleplay is that it takes place in the multiverse. It even has [[GuardianoftheMultiverse Guardians of the Multiverse]] which are the creators of the multiverse as well.
* Really, what would TheMultiverse be like without WebOriginal/JennyEverywhere?[[note]]Who, for the uninitiated, exists throughout it and can travel around in it at will.[[/note]]
* The ''Roleplay/LeagueOfIntergalacticCosmicChampions'' was a multiverse. A few of the other universes were other cybersoaps on Nitcentral.
* ''WebOriginal/LittleLennyPenguinAndTheGreatRedFlood'' references a multiverse frequently. WordOfGod says that this multiverse is "anywhere where space and time exists", which is 99% of pretty much ''everywhere'', broadening the concept to disturbingly confusing new heights.
* A staple of Website/LiveJournal comms like Sages of Chaos, Dear Multiverse, The Lunatic Cafe, and Dear Mun.
* Website/TheMultiverseForum has roleplays that mainly take place in the multiverse. [[CaptainObvious Its also called The Multiverse.]]
* ''WebOriginal/ProtectorsOfThePlotContinuum'' treat every fictional continuity and canon as its own universe within a multiverse. There are several such multiverses, many being alternates of the one the PPC looks over.
* ''[[http://sosshinsei.proboards.com/index.cgi Suzumiya Haruhi no Yaku-Asobi]]'' adds a multiverse (and sliders) to the list of crazy things caused by the incident [[ArcWords "three years ago"]]. At least two slider factions consist of [[TheEmpire empires]] that span multiple dimensions (one of which officially encompasses around ''500'' and is ruled by an expy of [[VisualNovel/FateStayNight Saber]]).
* Wiki/TheWanderersLibrary is a massive library containing knowledge from millions of different universes, with portals called Ways that lead to other worlds. It's essential the linchpin of the Wiki/SCPFoundation universe.
* ''Literature/{{Worm}}'' and ''Literature/{{Pact}}'' take place in the same multiverse. While there is no overlap between the two, [[spoiler: both settings would have been destroyed if [[EldritchAbomination Scion/Zion and Eden]] had been able to enact their [[PlanetLooters original plan]].]]
* ''Roleplay/{{Glowfic}}'' likes this trope - characters [[DimensionalTraveler accidentally fall/teleport into]] another world and then arrange travel between them, find new worlds, meet their [[AlternateSelf alts]], [[WrongContextMagic trade]] [[TechnologyUplift resources]], {{Terraform}} planets (and become space empresses/emperors), and generally attempt to arrange to be [[StoryBreakerPower super powerful]] while [[LivingForeverIsAwesome improving]] [[SocietyOfImmortals all people's]] [[InfiniteSupplies lives]] in all applicable worlds.
* ''Literature/AnExaminationOfExtraUniversalSystemsOfGovernment'' is a {{Mockumentary}} of a scholar traveling through various universes, studying the different and unique forms of governments found in them.

[[folder:Western Animation]]
* The [[WhamEpisode season 4 finale]] of ''WesternAnimation/AdventureTime'': [[spoiler: The Lich opens the portal using the Enchiridion.]] The multiverse is a series of alternate planes that can be traveled to with [[CoolGate portals]] torn open by objects of power or opened naturally when they eclipse. In the center is the [[PlaceBeyondTime Time Room]] where TheOmnipotent lives whose Time wave emissions allow the flow of timelines for them all.
** And the ''WesternAnimation/UncleGrandpa'' / ''WesternAnimation/StevenUniverse'' crossover has Mr. Gus stating he is aware of all of the magical denizens of the multiverse; when Uncle Grandpa leaves at the end, he pulls out a checklist of other Cartoon Network shows he's visited, presumably elsewhere in the multiverse. Also on the list are some Creator/HannaBarbera / Creator/{{TBS}} characters- the WesternAnimation/SwatKats.
* Video Land in ''WesternAnimation/CaptainNTheGameMaster'' is basically a universe for each video game plus the Real World.
* ''WesternAnimation/FamilyGuy'', "Road to the Multiverse". Another Brian and Stewie RoadTrip episode, this time going through a Sliders-inspired adventure. Some universes were an AlternateHistory (where Japanese never surrendered in WWII, the Cuban missile crisis, etc.), while others were the characters done in different art styles (the Disney universe, Robot Chicken universe, political cartoon universe, blocky universe, etc.). There was even a short trip to the real world.
* ''WesternAnimation/{{Futurama}}'' did this, and we discover a world where coin flips always have the opposite results -- as a result, Leela and Fry are married, Bender is gold-plated instead of his usual color ("Bite my glorious golden ass!"), etc. As it turns out, both universes are stored in a box in the other one.
** They later visit dozens of other universes -- ones where they're all [[PlanetOfHats robots, or hippies, or Romans...]]
** Also, in an earlier episode of ''WesternAnimation/{{Futurama}}'', there was another universe from across the edge of the universe -- where the Planet Express crew saw their counterparts dressed as cowboys. At that time, it was said to be the only other universe.
*** WordOfGod claims in the DVDCommentary that the cowboy one was a parallel universe (thus they're always the same distance from each other but never accessible to each other), the others are ''[[ShownTheirWork perpendicular]]'' universes (which means they're accessible to each other but only for a limited amount of time).
* In ''WesternAnimation/GravityFalls'', it's eventually revealed an inter-dimensional portal that connects to the multiverse (the main characters' home dimension is referred to as "Dimension Forty-six-apostrophe-backslash" in "Dungeons, Dungeons and More Dungeons") is hidden in [[spoiler: the basement of the Mystery Shack]]. It was originally built by [[spoiler: the Author of the journals, who was tricked into building it by [[GreaterScopeVillain Bill Cipher]] and was accidentally sucked into the portal himself thirty years before the events of the series. ''Literature/GravityFallsJournal3'' details some of the alternate worlds the Author visited, including a few alternate versions of Earth.]]
* ''WesternAnimation/JusticeLeagueCrisisOnTwoEarths'' takes a serious look at this trope to the point of near-deconstruction: [[spoiler:The main antagonist, Owlman, goes completely NietzscheWannabe over the realization that the multiverse consists of the ''[[TheMultiverse sum of all universes made from all possible outcomes of every single choice ever made by any sentient being]]'' (let's just be generous and say 'infinity'). Anything done is by definition meaningless because an infinite amount of universes exist that contain all possible outcomes of everything. Naturally, his conclusion [[OmnicidalManiac is to perform the one action]] that would, by definition, have any purpose at all because it cannot have a different outcome: '''[[WesternAnimation/BatmanBeyond Blow it all up!]]'''.]]
** This was also alluded to in the series ''WesternAnimation/JusticeLeague''. The main timeline exists on its own, and any changes to the past (as seen in both "The Savage Time" and "Hereafter") will affect the future itself as opposed to branching off -- the BadFuture of both respective stories is completely erased after someone SetRightWhatOnceWentWrong. That said, there ''are'' implied to be multiple universes which diverge off the regular one seen -- "A Better World" showed a ForWantOfANail wherein Lex Luthor became President of the United States, had the Flash executed and nearly started WorldWarIII; this led to Superman killing him and the Justice League to reinvent themselves as a group called the Justice Lords, with a KnightTemplar policy towards peace and security. In addition, the above-mentioned "Crisis On Two Earths" was originally written for the DCAU; although reinvented as a more general tale, it's fair to say that some version of that movie's events did happen in between JL and JLU (albeit with John Stewart as the serving Green Lantern, among other aesthetic differences), meaning that its own multiversal concept would apply here as well (if unexplored).
* ''WesternAnimation/RickAndMorty'': The entire plot is about Rick and Morty traveling across a lot of different and bizarre Alternate Universes.
* The end of ''[[WesternAnimation/SpiderManTheAnimatedSeries Spider-Man: TAS]]'' featured a team-up of several Spider-Men to prevent [[OmnicidalManiac Spider-Carnage from destroying a multiverse]]. One of them didn't have any powers and was really an actor playing Spider-Man in a movie. [[HilariousInHindsight His universe was strongly implied to be "ours"]].
* ''WesternAnimation/StarVsTheForcesOfEvil'': Star boasts she's "a magical princess from another dimension" in the series premiere, and her adventures with Marco occasionally take the two of them and their friends to other dimensions. The most common form of travel between dimensions is apparently "dimensional scissors", which are forged by Hekapoo of the Magic High Commission and given to those she feels worthy.
* ''WesternAnimation/TeenageMutantNinjaTurtles2003'':
** The TV movie ''WesternAnimation/TurtlesForever'' establishes that every single version of the ''Franchise/TeenageMutantNinjaTurtles'' (i.e. every single comic, TV, and film series) all exist simultaneously as separate universes in a multiverse. [[WesternAnimation/TeenageMutantNinjaTurtles2003 The Shredder]] [[GoMadFromTheRevelation gets rather pissed]] when he discovers that there are teams of Turtles in each one.
** The Battle Nexus fighting tournament draws in combatants from all over a multiverse that appears to be a sort of different multiverse concept. ComicBook/UsagiYojimbo's world is one of them. The Turtles are later scattered across the multiverse by Drago: Donny and Mikey end up in worlds with turtles (a BadFuture and a superhero reality), but Raph and Leo end up in totally different places.

[[folder: RealLife]]
* Many physicists, astronomers, and cosmologists are coming up with the possibilities of other worlds, and that there is more than one universe, but multiple universes in the "multiverse". This idea has been theorized in quantum physics, religions and philosophy. Even though the theory is quite popular in many science fiction and fantasy franchises, many scientists are trying to find proof of existing universes. Some believe we are living in parallel universes that had different timelines, alternate histories, and different, but similar environments. We may have alternate counterparts who may either have either similar lives as ours or completely different lives than we do. The scientists today are still trying to find ways of traveling into other dimensions, but the existence of infinite universes has not been confirmed yet.
** On the other hand, while a multiverse offers an interesting (and convenient) plot device for fiction and literary works, in reality it creates just as much problems. There are a lot of physicists and other scientists who are highly sceptical of the whole thing and consider the multiverse to be just another scientific blunder (a'la Lamarckian evolution, Geocentrism, Body Humours etc.). One of the foremost problems is defining just what a multiverse would entail or contain. Some have even gone so far as to label the multiverse theory an example of "sexy physics" meant to garner popular interest and publicity, rather than being a true scientific work. In the end, only time will tell how much, if at all, is the multiverse hypothesis is valid.
* As noted above, scientists have speculated for long about the possible existence of other universes, and even have classified the types of them that could exist. Two examples of that classification are the ones of [[https://en.wikipedia.org/wiki/Multiverse#Max_Tegmark.27s_four_levels Max Tegmark]][[note]]For people too lazy to follow the link, they are: Level I -regions of an (infinite) Universe (''very'', ''very'', ''[[RuleOfThree very]]'' far) beyond the observable one, that obviously would follow the same physical laws of our patch of the Cosmos-, Level II (universes product of variants of the inflationary theory as [[https://en.wikipedia.org/wiki/Eternal_inflation eternal inflation]], where stuff as physical constants, number of dimensions, etc. would vary), Level III (result of the [[https://en.wikipedia.org/wiki/Many-worlds_interpretation many-worlds interpretation]] of quantum mechanics) and Level IV ([[EldritchLocation Universes whose very fabric]] [[AlienGeometries would be totally different of ours]])[[/note]] and [[https://en.wikipedia.org/wiki/Multiverse#Brian_Greene.27s_nine_types Brian Greene.]][[note]]They include Tegmark's types plus others expected to exist in string theory, the possibilities of simulated realities, etc.[[/note]] Note in any case that the hypothesis of the multiverse, besides some [[http://arxiv.org/abs/1510.00126 claims]], cannot so far be falsified (tested to see if it's real or not) and evidences presented as proof of its existence are indirect at best, this explaining why as explained above a significant number of scientists consider the multiverse hypothesis little more than pseudoscience. However the first level of both classifications is the most favored, as data from space missions that have studied the cosmic microwave background as ''WMAP'' or ''Planck'' seem to favor an infinite Universe, or at the very least one mind-bogglingly big.
** According to the laws of physics, matter cannot be created or destroyed (it can only change form); if the universe truly ''is'' infinite in size, there are still only ''n'' number of possible ways that matter can assemble. Hypothetically, if you travel in an arbitrary direction, for an arbitrarily long period of time, you will eventually exhaust every possible 'unique' configuration of matter, and effectively enter a 'duplicate' universe that is identical to your universe of origin. This is the first entry of both classifications of Universes and considered the most likely to exist.