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 Another Dimension, an Alternate Universe, or an Alternate 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, also known as the megaverse, omniverse, or outerverse 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 a multiverse voyager allows themselves to experience and be aware of, because the worst atrocities imaginable already exist in every possible form and can never be prevented. One can only choose to experience the kinder, gentler timelines, while recognizing the others exist and actively choosing to ignore them.
At the same time, a multiverse voyager could choose to experience atrocious timelines in the multiverse, knowing that they are responsible only for choosing to be aware of them, and not for actually causing any of the events of the timeline, because the events in those timelines are already fixed and can not be changed. Any attempt to "change" the events of a timeline simply results in experiencing one of the many paths diverging 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 Travelers 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 Devices available but the most common are gateways or Magic.
In fantasy settings, the other worlds are often referred to as "planes of existence", and are alternate dimensions. In most science fiction settings, the other worlds are often entire parallel universes or Alternate Timelines.
This provides all sorts of interesting ideas for things you can do, for good or bad. If it involves trans-universe Sex Tourism, you have Your Universe or Mine? (or Screw Yourself sometimes). However, beware Evil Twin, and similar beings.
It is not the same thing as Alternate Continuity — which refers to a separate universe (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 Bizarro Universe, Another Dimension and Alternate Universe. Compare Rubber-Band History. If one universe acts as a Cosmic Keystone that the others are based on, that's The Earth-Prime Theory.
- Bokurano: The main characters are fighting aliens who are attempting to destroy the Earth. Eventually it is revealed that the aliens are 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 alternates of individuals from one world to another are very rare.
- This concept is briefly utilized in Cross Ange 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 current Earth.
- Said villain's motivations lead into Omnicidal Maniac 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 Digimon appears to be a case of regular continuity reboots, the 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 Digimon Adventure 02 and Digimon Xros Wars: The Young Hunters Who Leapt Through Time, which are sequels and so exist in the same world); the WonderSwan games follow Ryo Akiyama's travels between a few of them. Digimon V-Tamer 01 had three special chapters in which Taichi Yagami and Zeromaru interact with other Digimon universes, namely those of Digimon Adventure (which has its own version of Taichi Yagami), Digimon Frontier and the 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 Ryo Akiyama) you can travel between them. In addition, some canons have other dimensions tied to that particular universe; Digimon Adventure 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 Digimon Xros Wars: The Young Hunters Who Leapt Through Time features DigiQuartz, a bizarre Dark World in between the Real and Digital Worlds.
- It's also important to note that certain Digital entities can actually violate the multiverse's rules. For example, as revealed by Mirei Mikagura, the Seven Great Demon Lords exist in all possible realities at the same time, meaning each universe has their own set of Demon Lords. This is done as a way to ensure their continued existence. If they are absent in any one reality, then they have already been defeated in that particular universe. Which is actually bad for the other realities, who have to cope with the fact that their own set of Demon Lords just became stronger.
- Dragon Ball:
- Dragon Ball Z: 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. Dragon Ball Super 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 (even with 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. And then it's subverted in the final episode and revealed to be a gigantic Secret Test of Character. Android 17 wishes the destroyed universes back with the Super Dragon Balls, which is what Zen'o wanted and fully expected to happen from the very beginning (since he believed that whomever won the tournament would have to be a virtuous person). His assistant, the Grand Priest, reveals that if the winner had made a selfish wish, Zen'o would have erased everything.
- Dragon Ball Z 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 guidebooksnote . In Super, Trunks' timeline — every last bit of it — is erased by Future Zen'o-sama to prevent Zamasu (now an Eldritch Abomination) from bleeding into the present and destroying it. But it's not much of a loss, since off-screen Zamasu had apparently slain all the gods and every sentient being except for a tiny handful of Earthlings, and they all died within the first few moments of Zamasu becoming a cosmic horror.
- According to Dragon Ball Xenoverse and its sequel, the events of Dragon Ball GT and the 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.
- Dragon Ball Z: 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. Dragon Ball Super 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.
- Genesis of Aquarion 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 Aquarion Evol, as 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.
- The Girl In Twilight is about five girls who discover a way to travel between parallel universes. They soon find themselves drawn into a multiverse-spanning war against the eponymous Twilight, a cosmic force that is invading and destroying the universes.
- In 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.
- HuGtto! Pretty Cure uses this to its advantage not just for crossover reasons, but for story purposes as well, as the main villains originated from a Bad Future that was caused by Hana not transferring schools at the start of the series, leading to her being stuck in a hostile environment that ultimately resulted in her death. Meanwhile, all of the Cures from previous seasons are able to come back due to them being stated to be from alternate universes, suddenly bringing new context to the Pretty Cure All Stars series.
- JoJo's Bizarre Adventure: Part 7 introduces the concept of infinite universes by not only setting this story in a different one from the other parts, but also through Funny Valentine's Stand "Dirty Deeds Done Dirt Cheap", which can travel from one universe to another.
- The setting of Lyrical Nanoha is advanced enough to have fairly casual inter-dimensional travel, with the Time-Space Administration Bureau monitoring the security, safety, and cultural growth of every dimension.
- The setting of the Mazinger Z franchise is this: Shin Mazinger Zero established that the original Mazinger Z timeline and all alternate timelines and realities seen in the story are part of a multiverse which includes the universes of Great Mazinger, UFO Robo Grendizer, Getter Robo, Kotetsu Jeeg, UC Gundam, Gunbuster and Neon Genesis Evangelion, among others.
- From some point of the series onward, Hatou in Murasakiiro no Qualia can interact with all the parallel worlds. Each of these is one of the infinite possibilities for the flow of events that didn't get determined in her world.
- Though not confirmed officially, the Neon Genesis Evangelion franchise 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 Rebuild films.
- Noein has this where every universe is a For Want of a Nail situation, running off the theory that for every decision made, Another Dimension is created where the other option was chosen. Much philosophy ensues.
- Reborn! (2004) has Byakuran become a Physical God of all parallel universes, using the three sets of rings and pacifiers in order to do so.
- 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. 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 Plot Coupon weapons from their universe
- Space☆Dandy initially appears to be flagrantly ignoring its own continuity, with the main characters often dying at the end of an episode only to turn up in the next. It's revealed to be somewhat more complicated as things go on, particularly in the second season. The second season's opening episode 'I Can't Be The Only One, Baby,' sees Dandy and his friends meet multiple versions of themselves from various universe linked by a cosmic string. The universes reference various other anime and sf franchises. The final episode reveals that Dandy is the only being in the multiverse able to cross through the different dimensions, leading to God offering him the position of his replacement. He declines.
- Tenchi Muyo! is the one huge metaseries with literally tens of alternative continuities, explored in various TV series, OVAs, 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 explicitly stated by its creator, Masaki Kajishima, that all 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 Tenchi Muyo! Ryo-Oh-Ki (that is, original OVAs) storyline and its spinoffs like Tenchi Muyo! GXP, and considers it the main and central storyline.
- Tengen Toppa Gurren Lagann: Three Words: Multi-Dimensional Labyrinth. The Anti-Spiral effectively flings the consciousnesses of every member of Team Dai-Gurren to 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 in a "super-spiral universe where thought is given form."
- Toriko reveals that after the Gourmet Big Bang, the Gourmet Gods energy would form 5 universes that came into existence, the Red Universe, the Blue Universe, the Green Universe, the Black Universe and the White Universe. Their favorite ingredients of the Gourmet Gods became known as Acacias Full Course Menu. Neo and the Blue Nitro come from the Blue Universe and Neo itself has eaten the entirety of that universe including stars and galaxies.
- Yuuko from ×××HOLiC is called the Witch of Dimension for her ability to create gates to any Alternate Universe. It's her services which allow the cast of Tsubasa -RESERVoir CHRoNiCLE- to hop from one dimension to another trying to collect all the feathers.
- A.A. Pessimal has created several ongoing tales concerning the 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 The Big Bang Theory in The Many Worlds Interpretation. His Assassin girlfriend 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 Bloody Rose Series is a metaseries of different fanfiction series in a shared multiverse, starring the Japanese pop idol group AKB48.
- The Blooming Moon Chronicles, 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 My Little Pony: Friendship Is Magic). The further away a world is from the core, the greater the differences between that world and the TV show.
- 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 Running Gag, 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 Code Geass: Occulta Rising.
- Code: Pony Evolution uses this to explain how the worlds meet.
- Crossover Chaos takes this trope and runs with it, not only in terms of Canon Welding all the series featured (as well as Real Life) 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 Real Life as well.
- A Crown of Stars: Throughout the history Asuka and Shinji travel between dimensions several times and meet several of their other-worldly counterparts. King of Avalon Daniel rules a chunk of the multiverse. He has seen and visited many alternate realities.
- A large number of Dark Mark's DC Universe fanfics are set in the same Multiverse. Kara of Rokyn alters the outcome of Crisis on Infinite Earths, saving the infinite parallel universes and spawning new parallel dimensions, some of them seen in Hellsister Trilogy and A Force of Four, whose heroes every so often interact with each other.
- The premise of Eggman Generations, with three versions of Eggman gathering a group of their alternates, so that they can come up with a clan to beat Sonic.
- The Emiya Clan runs on this. With a few exceptions (the Shonen Jump big three, Warhammer 40k, Fairy Tail, 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 time travel, dimension hopping, space, or magician relatives, any idea can make an appearance so long as the authors approve it.
- Evilhumour has the "Powers-That-Be" multiverse that ties in a lot of his My Little Pony: Friendship Is Magic fanfics, with at least fifteen (or more) universes in a set of linked but separate versions of Equestria. These universes include the Blinds-verse, Broken Star-verse, Cassius-verse, Diplomacy-verse, Doa-verse, Galloping Waves-verse, Harvest-verse, Pieces-verse, Reflecting Shield-verse, Suspenders-verse, Testing-verse (with two branches), Two Moons-verse, Worlds-verse, Survival and Twisted Fate. Connecting elements include the presence of "Powers" in each world, a set of entities who each have a Purpose, Role and Duties, and their involvement with their worlds and others.
- Major staple in Hottie 3: The Best Fan Fic in the World on the count of it being a Massive Multiplayer Crossover. There is also the concept of the omniverse, a multiverse of multiverses. There are a total of thirteen multiverses in the omniverse.
- The Infinite Loops start because the computer the multiverse runs on had a system crash.
- Suzumiya Haruhi no Yaku-Asobi adds a multiverse (and sliders) to the list of crazy things caused by the incident "three years ago". At least two slider factions consist of empires that span multiple dimensions (one of which officially encompasses around 500 and is ruled by an expy of Saber).
- The author Kanius and his contributors has their concept by having Sailor Cosmos living in the Galaxy Cauldron to connect many nexus dimensions. This is where the universes of Digimon Fusion Kai (DF-616), YuYuGiDigiMoon (YYGDM-01), and 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 Digimon Fusion is involve with them.
- There are also other universes that references them such as Guilty Crown: The Lost Kingdoms (GCLK-1113) alongside Kanius Production Abridged (Shared Character Corner, including Shinnen New Year that takes place as the series finale).
- Mirror Multiverse uses this as a plot device, with the main characters hopping around a collection of universes.
- My Brave Pony: Starfleet Magic: 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".
- League of Extraordinary Gentlemen: Tempest Rewrite: The existence of the world of LXG (and this fic) is explained using the The World as Myth concept from The Number of the Beast, and is also revealed to be a part of the Eternal Champion multiverse
- The Pony POV Series establishes one of these when Applejack looks into the Truth and sees a multitude of Alternate Universes, many of which are Shout Outs to other fics or anime/cartoons/television/etc. It's also with noting that the series uses The Multiverse — 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 "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 (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. Applejack ends up meeting Orangejack, and together they defeat their potential Nightmare-self, Nightmare Mirror. The other universe, which gets even more attention, is the Epilogue timeline, which shows what would have happened had Discord won — he turns the discorded Mane Six into his enforcers, and turns the world into Pony Hell.
- There are also a few bits of Recursive Fanfiction that are written as Alternate Universes to the main POV-verse, but so far only one has been declared official by the main author.
- Royal Heights 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.
- Stars Above uses this concept.
- By the same author, the Magical Girl Crisis Crossover Shattered Skies: The Morning Lights establishes a multiverse consisting of five "Vertices": the Sailorverse (90s anime and manga/Crystal continuities), the Cardcaptorverse, all of the Precure continuities up through Go! Princess at first, the Nanohaverse, and the Madokaverse.
- The Subspace Emissary's Worlds Conquest is a multiverse of all the video game settings the author can think of.
- The Multiverse plays an important part in Super Milestone Wars and its sequel.
- The Multiverse also plays an important part in The Sweetie Chronicles: Fragments: 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 Tengen Toppa Gurren Lagann 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 Universes that make up the Multi-Dimensional Labyrinth are created the instant they are perceived.
- The Bridge eventually develops one of these, as while it starts with just Equestria and Terra (the Massive Multiplayer Crossover Kaiju version of Earth), it also later adds on Zenith, the Equestria Girls universe, the Power Ponies universe and its EG counterpart, as well as a Mirror Universe of the latter, the Mirror Universe of Equestria from the comics and its Terra counterpart, and in a later crossover story brings in The Shimmerverse as another separate universe.
- The Lone Traveler stories. Basically the author took the idea of Quantum Leap and merged it with a Harry Potter from the 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 'The Lone Traveler'
- The PreDespair Kids touches on this concept from time to time, as the story itself gradually moved into an Alternate Universe for Danganronpa, especially after Mukuro's HeelFace Turn and Mikan's 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.
- Thousand Shinji: In the original series, Third Impact created thousands of alternate universes. The "Thousand Shinji" timeline is part of a multiverse which includes the timelines of Shinji And Warhammer 40 K, Once More with Feeling, Children of an Elder God and Nobody Dies.
- Weiss Reacts is set in this, along with Lucina Reacts. The other verses are accessible by the Outrealm Gate and Blake's Lagann.
- With Strings Attached takes place in or mentions at least six different universes, and Jeft refers to existence as the Infiniverse.
- Project Dragon, Project Wildcat and Project Hound, three long lists doccumenting the many versions of Sash Lilac, Carol Tea and Milla Basset (respectively) from Freedom Planet, with the 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, such as here.note
- This would later be extrapolated on with Project Panda, a multiverse list for Neera-Li, with similar lists for Torque and Spade being said to be coming soon.
- Adjacency: A Magic Mirror allows Twilight and Trixie to travel to multiple Alternate Universes of Equestria.
- This is an extremely prominent trend in Undertale fan works, as the sheer number of Recursive Fanfiction has created many Massive Multiplayer Crossovers. In fact, several Original Characters were created specifically to function in a multiverse setting, such as Ink and Error — the Creator and Destroyer of Alternate Universes respectively. One of the best examples is Underverse, which essentially covers a war across the Multiverse as Cross is trying to restore his Universe to normal, while Ink and Error are balancing their truce on a tightrope, XGaster plans to conquer the original world and every other Universe in existence (all fanworks from other creators) gets dragged into the conflict in some fashion.
- Not the intended use (Zantetsuken Reverse) reveals that there are multiple different universes where all the different characters are from. In fact, there is this one city where everyone has a doppelgänger from another dimension running around. Naoki blames a good chunk of the chaos on himself as he tried to recreate his original reality but was unclear on the details.
- The Dimensional Drifter: The summary itself admits that for Judai, multiversal travel is just another Tuesday for him. So the news that the dimension he ended up in is part of a set of dimensions separate from the one he is familiar with, and that said dimensions are at war with each other is not really a surprise to him.
- Spider-Man: Into the Spider-Verse posits that there are an infinite amount of realities, six of which collide in the movie, with each bringing in their own Spider-Person. Plus two more in The Stinger. This is caused by the villain, Kingpin, building a machine to navigate the multiverse so he can find a universe where his wife and son are still alive and bring them back. However, beings native to one universe can't stay in another too long, as they begin breaking down on the cellular level. The plot quickly becomes a matter of not only stopping Kingpin from destroying New York in a reality-breaking universe crash, but also returning the alternate Spider-People home before they all die a slow and painful death.
- Phineas and Ferb the Movie: Across the 2nd Dimension, a Made-for-TV Movie based on the Disney cartoon, spends most of its time between the "main" dimension where the TV show is set and the titular 2nd Dimension. As Baljeet-2 explains, the mulitversal flow of energy works like a clock — it's relatively easy to follow the energy flow clockwise, but going counterclockwise will require either an Other-Dimension-Inator or a truly absurd amount of energy, and there's an unknowable number of dimensions one must go through to return to their starting point. The musical number "Brand New Reality" sees the characters from the first dimension take the long way around to get back home.
- Teen Titans Go! vs. Teen Titans not only has the Teen Titans of the 2013 animated show team up with the Teen Titans of the 2003 show, but also has them encounter versions based on prior episodes from Teen Titans Go!, which were theorised earlier in the film and even from other DC media. They eventually all team up to form the Teen Titans of Infinite Earths.
- Army of Frankensteins: Each Frankenstein is from a different universe, due to an experiment Gone Horribly Wrong rupturing a hole in the Multiverse.
- The sci-fi thriller Coherence explores the idea of Alternate Timelines crossing paths during a Temporal Paradox caused by a comet passing earth.
- DC Extended Universe:
- In Zack Snyder's Justice League, a dialogue between Steppenwolf and Diana indicates that the forces of Darkseid originate from "the dark place", meaning its own universe and not just somewhere else in the physical plane. Steppenwolf even mentions that the end goal of Darkseid is the domination of the Multiverse.
- The Flash is the first DC Comics-inspired film to explore the concept. It will feature Barry Allen/The Flash (Ezra Miller) traveling to another universe's Earth and meet the Batman played by Michael Keaton. The Batman played by Ben Affleck will also appear in the film. The movie is a loose adaptation of the comic storyline Flashpoint.
- The movie Everything Everywhere All at Once is centered around the Multiverse. It centers around Evelyn Wang, a normal middle-aged Chinese American woman trying to get her taxes done. In the middle of a meeting about paperwork at the IRS office, she's suddenly whisked away and split between two alternate realities. It's revealed that there's something threatening the very fate of what she discovers to be the multiverse, and she may be the only chance of stopping it. Evelyn can access all the abilities, memories and emotions of her alternative selves, making her an incredibly skilled albeit reluctant heroine.
- The Marvel Cinematic Universe has the multiverse as a major concept. The second saga following the Infinity Saga is even known as "The Multiverse Saga".
- When first introduced in Doctor Strange, the multiverse contains every dimension in existence, such as the Quantum Realm and Dark Dimension.
- In Loki, it's revealed that the multiverse contains every single timeline in existence. Initially, the multiverse was discovered by a scientist simply known as He Who Remains. Alternate versions of this person discovered the multiverse at the same time, and the variants coexisted peacefully. However, some power-hungry versions of He Who Remains sparked a multiversal war that threatened the destruction of everything, so He Who Remains reorganized every timeline in the multiverse into one singular timeline in order to prevent his variants from reemerging. However, after Sylvie kills He Who Remains, the multiverse is fully reborn.
- This concept of the multiverse is further explored in What If...?, with each episode exploring an alternate takes on various events from films in the MCU.
- In Spider-Man: No Way Home, people from alternate universes with connections to Spider-Man — i.e. characters from the Spider-Man Trilogy and The Amazing Spider-Man Series — start appearing in the Marvel Cinematic Universe. Initially it's just villains, specifically Green Goblin (Willem Dafoe), Doctor Octopus (Alfred Molina), the Sandman (Thomas Haden Church), the Lizard (Rhys Ifans) and Electro (Jamie Foxx). In the third act, Tobey Maguire and Andrew Garfield also appear, reprising their respective roles as their own individual incarnations of Spider-Man.
- Sony's Spider-Man Universe also exists within the MCU multiverse; the mid-credits scene of Venom: Let There Be Carnage has Eddie and Venom also get sucked into the MCU and see Spider-Man's true identity be exposed, until the post-credits scene of Spider-Man: No Way Home, where theyre suddenly teleported back to their own universe, while unknowingly leaving a piece of the symbiote behind. Conversely, The Stinger of Morbius has the MCU Vulture get sucked into Sony's Spider-Man Universe in the aftermath of No Way Home. Meanwhile, The Stinger for Venom (2018) said that the events of Spider-Man: Into the Spider-Verse took place at the same time as the film but in a different universe, making that film part of the MCU multiverse.
- Doctor Strange in the Multiverse of Madness has Stephen Strange and other characters traveling between universes and meeting variants of themselves, their friends and enemies, and characters from other corners of the Marvel universe (i.e. from live-action Marvel properties that weren't/aren't canon to the MCU). Most notable is Strange's meeting with the Illuminati on Earth-838, which consists of variants of Baron Mordo, Peggy Carter, Maria Rambeau, Black Bolt, Reed Richards, and Charles Xavier.
- The Big Bad in the movie Last Action Hero 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: Freddy Krueger and 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 the bad guys can win!.
- The basic premise of The One 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 Parallels.
- Norse Mythology presents a cosmology of Nine Worlds, connected by a gigantic World Tree. 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?)
- Buddhist, Hindu and Jain cosmologies also speak of several realms or lokas. In the case of Buddhism there are six primary realms: human, animal, pretta, hell, deva and asura, each of it also subdivided (for example, there are ten hell sub-realms). Realm might mean both literally a plane of existence or a state of mind. And no, the Nirvana is not included, as it is a status and not a physical place.
- Some texts of Mahayana Buddhism state that there is a multiplicity of worlds even in each realm, some of them more pleasant to live in than others, and encourage those pursuing the road of the Bodhisattvas to travel to the worst worlds in order to paliate their suffering.
- In the first episode radio series 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.
- JLA Watchtower and DC Nation laughed off "52 Pick Up" (as referenced above), going with the older concept of Hypertime.
- The Multiverse is a 20-year ongoing written collaborative fiction and Multi-User Dungeon, where you can still create a character and add to the ever evolving story. Every genre is represented.
- DC: United We Stand is set in one of the many different parts of DC's multiverse.
- Fire Emblem On Forums has two examples, even:
- Legacy FEF retroactively put every roleplay in the series in one, drawing multiple heroes from various settings to fight.
- Wonderful Blessing (and thus its Gaiden Game Whereabouts of Drink and Coin), Demon Soul Saga, Chains of Horai and Solrise Academy take place in one of their own.
- The basis of the Go Through The Alphabet Before Somebody Posts A My Little Pony Picture Roleplay is that it takes place in the multiverse. It even has Guardians of the Multiverse which are the creators of the multiverse as well.
- The League of Intergalactic Cosmic Champions was a multiverse. A few of the other universes were other cybersoaps on Nitcentral.
- The Multiverse Forum has roleplays that mainly take place in the multiverse. It's also called The Multiverse.
- Glowfic likes this trope — characters accidentally fall/teleport into another world and then arrange travel between them, find new worlds, meet their alts, trade resources, Terraform planets (and become space empresses/emperors), and generally attempt to arrange to be super powerful while improving all people's lives in all applicable worlds.
- The GURPS supplement Infinite Worlds 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 Magic: The Gathering is set in a multiverse, with each expansion set representing a new universe (well, mostly). Originally this was referred to as "Dominia", but because of how easy it was to confuse with "Dominaria", one of the universes (the one that was the main setting of the game in its early days), it was renamed to simply "the multiverse". 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.
- Dungeons & Dragons has developed no fewer than five separate multiverses across its prolonged history.
- The oldest and most forgotten multiverse was built for the original Dungeons & Dragons gameline, centered around the setting of Mystara. This multiverse is made up of many different parallel dimensions and alternate realities... but because of age and the system's overshadowing by Advanced Dungeons & Dragons, nobody except the small, diehard fanbase really remembers how it was laid out.
- Advanced Dungeons & Dragons, in comparison, built its own multiverse, which it names "The Great Wheel", due to it being physically represented as concentric rings expanding outwards. All of its settings are formally made up of this multiverse, which consists of the following planes: this is the most well-known of the D&D multiverses, and was used for both editions of AD&D and for 3rd edition.
- The Prime Material Plane: Also alternatively known as either the Prime or the Material Plane, this is the "normal" reality, the mundane level of existence where all of the various setting worlds take place, the physical universe. The setting Spelljammer would further expand upon the nature of the Material Plane, declaring it a kind of Science Fantasy reality in which inhabited solar systems occupy "crystal spheres", which are bubbles of reality floating in an infinite ocean-like plane known as "Wildspace" or "The Phlogiston"; by breaching a crystal sphere and sailing through Wildspace, beings can move from the solar systems of the various settings.
- The Ethereal Plane: The realm of ghosts and spirits, a misty mirror of the material plane.
- The Plane of Shadow: Basically a dark and spooky mirror of the material plane, where light and dark have been inverted.
- The Elemental Planes: An array of planes that are the metaphysical source of all elements in the multiverse. At their foundation are four "true" Elemental Planes — Air, Earth, Fire, Water — and two Energy Planes; Positive Energy (Life) and Negative Energy (Death). There are also four Paraelemental Planes, representing a conflux of two elemental planes (Ice: Air/Water, Ooze: Earth/Water, Smoke: Fire/Air and Magma: Fire/Earth), and eight Quasielemental Planes, representing a conflux between an elemental plane and an energy plane. The Positive Quasielemental Planes are Lightning (Positive/Air), Steam (Positive/Water), Mineral (Positive/Earth) and Radiance (Positive/Fire). The Negative Quasielemental Planes are Vacuum (Negative/Air), Salt (Negative/Water), Dust (Negative/Earth) and Ash (Negative/Fire)
- The Astral Plane: Sort of the "elemental plane of thought", most notable for being the barrier realm between the Inner Planes (Material, Ethereal, Elemental) and the Outer Planes.
- The Outer Planes: Seventeen different planes that embody different points on the 9-grid Character Alignment axis. The Morally Good planes are an assortment of heavenly realms known collectively as the Upper Planes. The Morally Neutral planes are called, simply, the Middle Planes. And the Morally Evil planes are an assortment of different hell-dimensions collectively known as the Lower Planes. Each individual plane takes its own particular spin on its general categorization; the plane of Arborea (Chaotic Good) is a realm of benevolent anarchy, whilst its neighbor the plane of Ysgard (which sits on the border of Chaotic Good and Chaotic Neutral) is a Valhalla-esque realm of glorious combat and self-satisfying struggle.
- The Far Realm: A later edition to the game, basically the "Plane of the Cthulhu Mythos".
- Planescape is unique amongst its peers in that it is a "cosmic fantasy" game; the focus is on exploring the Elemental, Astral and Outer Planes of the Great Wheel, instead of living on the Material Plane.
- 3rd edition Forgotten Realms adds a whole bunch of specific planes for its god to inhabit, instead of their realms just being situated on the Outer Planes fitting their alignment as in at least 2nd edition Planescape. Of course, 2nd edition Planescape already stated that the borders between things like planes, layers and realms is a bit fuzzy, so the difference isn't so huge aside from losing the neat system of the Outer Planes.
- Dark Sun officially has its own cosmology; the Material, the Grey, the Black, the Elemental Planes of Air/Earth/Fire/Water, and the Paraelemental Planes of Magma, Rain, Silt and Sun. However, it's revealed to Dungeon Masters that this is actually a result of Athasian ignorance of the wider multiverse, and in fact they inhabit the Great Wheel — just with a garbled picture of the cosmology.
- Eberron inhabits its own unique cosmology, commonly nicknamed "The Orrery" due to its maps, made up of 13 planes (though one has been "removed". Its planes are Daanvi (Plane of Law), Dal Quor (Plane of Dreams), Dolurrh (Plane of the Dead), Fernia (Plane of Fire), Irian (Plane of Day), Kythri (Plane ofe Chaos), Lamannia (Plane of Nature), Mabar (Plane of Night), Risia (Plane of Ice), Shavarth (Plane of War), Syrania (Plane of Air), Thelanis (Plane of Faeries), and Xoriat (Plane of Madness). Despite some debate amongst the fandom, officially, the Orrery is separate to the Great Wheel.
- In 4th edition, Wizards of the Coast replaced the Great Wheel with a new cosmology, smaller and more broad in its archetypes. This multiverse, known as the World Axis, is associated with the Nentir Vale, which was the core setting of 4th edition. The World Axis consists of the following planes:
- The World: Realm of Mortals, the physical universe.
- The Feywild: Realm of Faeries, a primal and magical mirror of the World, home to the fey.
- The Shadowfell: Realm of the Dead, a dark and decaying mirror of the World, birthplace of the undead and first point of departure for the souls of the dead.
- The Elemental Chaos: The Primordial Chaos from which the World and its mirror-realms were born.
- The Astral Sea: Realm of the Gods and the afterlives of their chosen worshippers.
- The Far Realm: The nightmarish unreality that lies outside of the World Axis, as in the Great Wheel.
- In 5th edition, a new cosmology made up of the Great Wheel with a simplified array of Elemental Planes and incorporating the Feywild, Shadowfell and Elemental Chaos from the World Axis was released as the "default" multiverse of D&D. The Eberron multiverse is also considered a part of the Great Wheel, but it's not explained how.
- Everway is a game about characters who can traverse a Portal Network which links a multiverse of fantasy worlds. Each world has its own distinctive flavor, drawing on various mostly mythical sources.
- Lords of Creation was one of the earliest such role-playing games, where it was not only meant to be possible but common for players to travel through time and into alternate universes, allowing players to be thrust into any setting imaginable. Some of the premade ideas included elemental planes, a fantasy world where famous mythological gods reign, the star-spanning empire of Imperial Terra in the farflung future, and the city of Paris in the age of swashbuckling. Driving it all home, the final tier in most skillsets would be "futuristic/magical", which meant the character had learned how to do everything else that skillset (detective, soldier, doctor, etc.) allowed them to do, with the means available in sci-fi or fantasy settings.
- Rifts is part of Palladium Books' "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 Sentinels of the Multiverse. The final expansion of the game deals with the end of that multiverse (according to Word of God, this is why the sequel game, Sentinels Tactics, doesn't include the word), and sees the heroes teaming up with alternate-universe versions of characters to stop an omnicidal Big Bad.
- 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.
- Wizards of the Coast 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.
- Tsukipro is, at first glance, a series about Idol Singer groups who sometimes perform plays about a variety of fantasy settings — Steampunk, Space Opera, Yōkai, to name a few — where the characters they play are Alternate Universe versions of themselves. Oh, and the leader of one of the groups happens to flaunt his magic powers and call himself the "Demon King", what of it? Well, that's that until the idols get Trapped in Another World — again and again. Yes, all of these fantasy stories are real, they're out there, and they can connect with the main setting at any time. Oh, and Shun isn't just a wizard, he's probably a god.
- During the Karda Nui arc, a Teleporter Accident sends Takanuva to an Alternate Universe 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 Big Bad crossing over into the main universe was set up during the same arc, but due to BIONICLE's abrupt cancellation, it ended up an Aborted Arc.
- Transformers has a whole pile of alternate universes which sometimes cross over, and which Hasbro and Takara disagree over which are actually separate and which simply occur to the side of other stories. The Transformers of the Axiom Nexus have grouped all continuities into a number of 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 GoBots, Quadwal is the real world, etc. Some of these are 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 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 All There in the Manual. There's no sign in any of the televised series or available-at-your-comics-shop comic booksnote — that is, any canonical stories — that you could "slide" from Transformers: Armada into Transformers: Animated, despite years of "collector's club" and convention exclusive materials that suggest you can. Fingers are still crossed around the fandom for a Turtles Forever sort of project someday, somehow.
- The Transformers Aligned Universe, which includes Transformers: Prime, Transformers: Rescue Bots, the 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 Transformers: Rise of the Dark Spark and The Complete AllSpark Almanac, and it's been revealed to be part of the larger Transformers multiverse, after all.
- An event called "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 "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.)
- The Nasuverse is actually made of different continuities, possibly because the main works are multi-route visual novels. However, actually traversing between Universes is the domain of Magic (i.e. a miracle) so only a very few characters 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.
- The Shinza Bansho Series didn't originally start as one, but thanks to the 4th Heaven, Mercurius, and his Eternal Recurrence it caused the whole universe to start and diverge. According to the series lore, for a multiverse to be possible a great deal of personal freedom is required as other universes exists as other possibilities. As Mercurius wanted to experience every possibility there is, it allowed for the birth of a multiverse in a verse where the laws of fate and gods is king.
- When They Cry uses and abuses this concept for its 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. Umineko: When They Cry 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.
- This is the basis of the sixth season of The Champions (2018). After wishing to be the G.O.A.T. forever, Leo Messi and Cristiano Ronaldo are transported to a universe where the Super League happened and where they are the '''G'''reatest '''O'''f '''A'''ll '''T'''ime '''F'''or '''A'''ll '''T'''time. After they escape the Super League Universe, they end up in universes where the United States wins the 2022 FIFA World Cup, they along with other big name footballers are all teammates at Newcastle United, and where, as that universe's Thomas Muller puts it, horses and people have become one Ronaldo ends up in another universe as well, one where the game of football doesn't exist, forcing him to reinvent the sport with that universe's Messi, who is a goatherder.
- In Homestar Runner, there are a lot of alternate universes. Just to name a few...
Retro Video Game Universe
Sweet Cupping Cakes Universe
- In 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.
- All Over The House 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 The Life of Nob T. Mouse.
- Awful Hospital: Reality outside our observable universe is partitioned into a multitude of practically endless realms known as the Perception Range, each "zone" constituting its own self-contained universe remarkably similar to ours with a unique set of rules and logic, operating differently for every being within them.
- Bob and George 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 Deviant Universe have appeared from alternate universes, and one story arc involved an attack by another universe.
- Dragon Ball Multiverse: 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".
- Dragon City: 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.
- El Goonish Shive 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 Susan's dad never cheated on his wife). And oddly, Tedd is in every universe, something that nobody else can claim.
- The Far Side Of Utopia 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.
- Homestuck has a multiversal setting, with the kids' universe and the trolls' universe playing a major role in the plot. It's later revealed that Sburb actually creates new universes that the players can then travel to, in the form of Genesis Frogs that hold universes within their bodies. Our home universe is the product of the trolls' session. Even later, it's revealed that Sburb actually creates multiverses; every possible alternate universe of a base template is encompassed in one Genesis Frog. The structure of the multiverse is also given description: the game sessions occur in stable bubbles within the Furthest Ring, an Eldritch Location which possess neither linear time nor linear space; in its "center" is the Green Sun. At the center of each completed session is a 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.
- Jix: Lauren was sent to an alternate dimension where Jix's other personality, Remula, rules Earth.
- The KA Mics is a multiverse and even has a company that allows travel between alternate universes.
- Kill Six Billion Demons: Once, there were 777,777 gods. They each built a universe of their own and populated it with their creations. Then they died. The universes they left behind are connected through Throne (or "Heaven" to the layman) through a Portal Network built by mortals who planeswalked into Throne and colonized it after the gods had died. Protagonist Allison arrives in Throne by accident, and is informed that saying you hail from 'Earth' doesn't help in finding her way home because there are over 300,000 known 'Earths', and presumably many more exist that haven't been connected to Throne yet (as is the case with Allison's).
- The Life of Nob T. Mouse contains a multiverse of sorts through its 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.
- Parallels: Keeping the spaceways safe one universe at a time.
- Scenes From a Multiverse, a comic about life in an ordinary multiverse.
- Sluggy Freelance 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.
- Ultima Java 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 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 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.
- Despite being titled Arcana Magi Universe, the series is a multiverse of five unique worlds, each named after The Four Gods.
- Dominion And Duchy 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".
- Really, what would The Multiverse be like without Jenny Everywhere? Who, for the uninitiated, exists throughout it and can travel around in it at will.
- Little Lenny Penguin And The Great Red Flood references a multiverse frequently. Word of God 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 LiveJournal comms like Sages of Chaos, Dear Multiverse, The Lunatic Cafe, and Dear Mun.
- Protectors of the Plot Continuum 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.
- The Wanderer's Library 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 SCP Foundation universe.
- Worm has a multiverse which plays heavily into the story. Early on it is mentioned casually that contact with another Earth had occurred and it seems largely unimportant (only communication is possible, not travel). However in the second half of the story the alternate universes come front and center as a portal to another Earth is created, it is revealed that many superpowers tap into alternate universes to function... oh and superpowers come from multidimensional beings who exist across multiple parallel universes at once. The sequel Ward features the multiverse throughout, as the events of Worm led to contact, travel and trade across over a dozen different Earths being initiated.
- Pact takes place in the same multiverse. While there is no overlap between the two as far as the events of the story are concerned, both settings would have been destroyed if Scion/Zion and Eden had been able to enact their original plan.
- An Examination of Extra-Universal Systems of Government is a Mockumentary of a scholar traveling through various universes, studying the different and unique forms of governments found in them.
- The Atop the Fourth Wall / The Spoony Experiment 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. Linksano purposefully uses this to gather an army of Insanos — and it works. Unfortunately they all start fighting each other afterwards.
- The season 4 finale of Adventure Time: The Lich opens the portal using the Enchiridion. The multiverse is a series of alternate planes that can be traveled to with portals torn open by objects of power or opened naturally when they eclipse. In the center is the Time Room where The Omnipotent lives whose Time wave emissions allow the flow of timelines for them all.
- And the Uncle Grandpa / Steven Universe 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 Hanna-Barbera / TBS characters- the SWAT Kats.
- A Ben 10: Omniverse story arc had a group of evil Bens attempt to eradicate all other Omnitrix users in the multiverse. The series finale (and, in turn, original continuity of the franchise) even ends with Ben creating a new universe.
- Video Land in Captain N: The Game Master is basically a universe for each video game plus the Real World.
- Family Guy, "Road to the Multiverse". Another Brian and Stewie Road Trip Plot episode, this time going through a Sliders-inspired adventure. Some universes were an Alternate History (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.
- 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 inside the other one.
- They later visit dozens of other universes — ones where they're all robots, or hippies, or Romans...
- Also, in an earlier episode of Futurama, there was another universe from across the edge of the universe — where the Planet Express crew saw their counterparts dressed as cowboys. Fry asks if there is an infinite number of parallel universes and Professor Farnsworth says "No, just the one."
- In Gravity Falls, it's eventually revealed an interdimensional 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 the basement of the Mystery Shack. It was originally built by the Author of the journals, who was tricked into building it by Bill Cipher and was accidentally sucked into the portal himself thirty years before the events of the series. Gravity Falls: Journal 3 details some of the alternative worlds the Author visited, including a few alternative versions of Earth.
- Justice League: Crisis on Two Earths takes a serious look at this trope to the point of near-deconstruction: The main antagonist, Owlman, goes completely Nietzsche Wannabe over the realization that the multiverse consists of the 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 is to perform the one action that would, by definition, have any purpose at all because it cannot have a different outcome: Blow it all up!
- This was also alluded to in the series Justice League. 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 Bad Future of both respective stories is completely erased after someone Set Right What Once Went Wrong. That said, there are implied to be multiple universes which diverge off the regular one seen — "A Better World" showed a For Want of a Nail wherein Lex Luthor became President of the United States, had the Flash executed and nearly started World War III. This led to Superman killing him, and caused the Justice League to reinvent themselves as a group called the Justice Lords, with a Knight Templar 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).
- The Midnight Gospel has its premise centered on this, being about a podcaster who runs a multiverse server farm in order to interview beings living in other worlds, many of which are on the brink of destruction.
- Rick and Morty: The entire plot is about Rick and Morty traveling across a lot of different and bizarre Alternate Universes.
- In an episode where Rick opens up several different portals with his portal gun, we see a mug with a question mark on it, a pen, and a notepad come out of one of them. These are implied to be the same ones that Stan had pulled away from him through the portal from Gravity Falls. The creators of the shows are friends, so this was intentional.
- In Sonic Prime, after shattering the Paradox Prism, Sonic unintentionally created several alternate versions of his home and all of his friends. Nine, an alternate version of Tails, dubs the new multiverse the "Shatterverse" and each dimension a "Shatterspace" within.
- The end of Spider-Man: The Animated Series featured a team-up of several Spider-Men to prevent 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. His universe was strongly implied to be "ours".
- Star vs. the Forces of Evil: 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. Some people, like Tom and eventually Star, can make interdimensional portals under their own power. The only other way known is though the Realm of Magic, which has permanent passageways connecting Earth and Mewni at the very least.
- Teenage Mutant Ninja Turtles (2003):
- The TV movie Turtles Forever establishes that every single version of the Teenage Mutant Ninja Turtles (i.e. every single comic, TV, and film series) all exist simultaneously as separate universes in a multiverse. The Shredder 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. Usagi Yojimbo'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 Bad Future and a superhero reality), but Raph and Leo end up in totally different places.
- Steven Universe, OK K.O.! Let's Be Heroes, and Craig of the Creek. All the shows take place in a fictional depiction of Maryland (or "Delmarva", as its referred to in Steven Universe), but on different levels of reality. Word of God states that OK KO is a video game series within the universes of the other two shows, while Craig is the "real world" that additionally has Steven and every other Cartoon Network series as television shows.
- Theories regarding a "multiverse" are popular with many scientists, particularly those who act as ambassadors with the general public. Many or infinite universes could help explain some features of our universe that are otherwise difficult to explain (e.g. it handily solves the "fine-tuning" problem: the unbelievably low probability that a universe with fundamental constants permitting the emergence of intelligent life would appear purely by chance. If an infinitely diverse multiverse exists, then it is not improbable at all: from an infinite set of dice rolls such a universe must necessarily appear, and only in those parts of reality where conditions are right would life arise to contemplate the question in the first place.) One could get the impression that the multiverse is a generally accepted scientific theory. In fact, it is highly contested, with some disputing that it even counts as "science." So far, no one has proposed any way to test for its existence, or make any falsifiable predictions using it, and such things might even be impossible. In an infinitely diverse multiverse, anything that can happen will happen. Therefore any observation can be accounted for in a multiverse theory which, by definition, predicts anything and everything. While it sounds more scientific, objectively speaking there is no more reason to believe in an infinitely large and diverse multiverse than in a creator diety, or that reality is a simulation run by aliens. Therefore it is not science. It is merely an idea, or as cosmologist Paul Davies wrote: theology dressed up as science. Cosmologist George Ellis wrote, "Nothing is wrong with scientifically based philosophical speculation, which is what multiverse proposals are. But we should name it for what it is."