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Canon Welding

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"They were independent, separate stories. But now...the stories are combining, that's why the worlds are becoming one."

When an author or creator takes two previously unrelated works and puts them into a single, shared continuity.

Sci-fi and fantasy authors don't always write all their novels in the same continuity. A budding new author's first published book might be about space pirates in the 27th century, while his sophomore effort might instead be about 21st century scientists reverse-engineering a flying saucer. In response to popular demand, he might end up writing a sequel to one, or even both of these novels. Flash forward about 20 years — the author has grown wealthy from writing stories about Captain Flash Orangebeard and Dr. Smith of Mars, but he's running out of ideas and the two long-running series are in danger of getting stale. What does he do to keep the public's interest, and breathe new life into the storylines?


Combine them!

Many long-lived genre authors tend to resort to Canon Welding, usually at a later point in their career. They combine two or more distinct series they've created into a single continuity. This isn't just a one-off Crossover; for series with radically different premises, the foundations of one or both stories can be altered forever.

By combining the two series together, the author can introduce fans of one series to characters they may not be familiar with, inducing them to go out and buy the works in that series, and hopefully attract high sales from fans of both storylines. When done well, it can add a more epic feel to the tale, explore aspects of the two storylines not previously delved into, and make lots of money for the author and his publisher (and there are many examples of this, perhaps most famously The Lord of the Rings). When done poorly, especially with stories with radically different settings or styles, it looks and feels like a shallow money-grab and can potentially be a shark-jumping moment for both series.


Modular Franchise is when it's done at a corporate level. When this is done by fans, it becomes either a Patchwork Fic if all of the components are part of a single Franchise or one variety of Fusion Fic if they are not. Compare Shared Universe, which can be created through Canon Welding if it wasn't shared from the beginning. Not to be confused with welding artillery.


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  • Chris Boucher's Doctor Who – Expanded Universe Past Doctor Adventures novel Corpse Marker, and his semi-licenced audio series called Kaldor City, both indicate that Blake's 7 takes place in the Whoniverse. Specifically, these show that Blake's 7 takes place in the same time period as Boucher's popular Doctor Who story "The Robots of Death".
    • This was very nearly canonical, as it happens; the invasion force from another galaxy from the finale of Season 2 of Blake's 7 were intended to be the Daleks at one point, but for one reason or another the idea was dropped.
    • Douglas Adams' character Professor Chronotis from the novel Dirk Gently's Holistic Detective Agency came from Adams' Doctor Who TV serial "Shada", which was left incomplete due to an electricians' strike. In the novel, at least partially for copyright reasons, it's not explicitly stated that Chronotis is a Time Lord in hiding, but it's clearly meant to be the same person. There's even an oblique little reference at the end to a strange young man permanently disabling his time machine while the POV character wasn't around...
  • In The '50s, Disney Comics began to spread until the canon of the comic stories encompassed not only the regular Donald-Mickey-Silly Symphoniesnote  melting-pot, but also several animated features by the studio, the most notably integrated into the canon being Song of the South, Snow White and the Seven Dwarves and Pinocchio. It was later taken to ridiculous extents in The '60s and The '70s, as the creators were beginning to run out of ideas. Aside perhaps of Snow White, The Sword and the Stone and Song of the South, the stories featuring such crossovers are very much Canon Discontinuity, though some fans disagree with that decision of the company — they say that some of those stories were bad, sure, but that they were bad because the writers didn't do their job, not because the crossover idea in itself was bad.
  • Super Robot Wars is already a Crossover series, with nearly as many canons as it has games — most entries take place in their own continuities, created by fusing together the stories of whichever Humongous Mecha shows are featured in that particular installment, but there are a few characters who show up in multiple continuities, and while most of them are Alternate Universe versions of each other, the likes of Gilliam Yeager for example, whose gimmick involves hopping between dimensions, is implied to be the same individual in all his appearances, no matter what continuity he's in. This in turn would make any games with Gilliam in them part of the same Multiverse.
  • The Endless Frontier series, which crosses over with both Original Generation (which features Gilliam) and the even-more-mega-Crossover Namco × Capcom. And since Namco × Capcom contains everything from Street Fighter to Xenosaga (which also crosses over to Endless Frontier) to Klonoa, there are versions of all of those characters (but not the same versions that exist in their original games, yet still a version) in the Banpresto multiverse. With Project X Zone, any Capcom and Bandai Namco Entertainment series not already included into this multiverse will most likely be added; however, there will also be dozens of Sega series in the game like Virtua Fighter and Valkyria Chronicles.
  • Kamen Rider:
    • The franchise has had this going since the beginning. The Showa-era shows (original through Kamen Rider BLACK RX) explicitly took place in the same universe, and the previous Riders would often show up near the end of the latest series to help out the current hero. The movies produced in the hiatus years (Shin Kamen Rider: Prologue, Kamen Rider ZO, Kamen Rider J) and the Heisei shows (Kuuga onwards) abandoned this, except for a few rare crossover events. Kamen Rider Decade deliberately says that the Heisei shows all occupy their own separate universe...and then has the first nine (Kuuga to Kiva) forcibly merged, with Decade forced to travel to alternate versions of said worlds in an attempt to fix everything...and then there's the Decade movie All Riders vs. Great Shocker, which crosses over with the entire Showa-era universe as well. Movie War 2010 also adds Kamen Rider Double to the mix. Then Kamen Rider Fourze decided to just bite the bullet and imply at the end of episode 2 that every show in the franchise is set in the same universe, with Word of God saying that they're going to Retcon the elements of Decade that didn't work. For extra humor, Kamen Rider Kabuto has a brief in-character cameo by the actor who plays Rider-1 in The Remake Kamen Rider: The First, and Kamen Rider Ryuki had a DVD-exclusive joke episode where the protagonist dreams that he teams up with Kamen Rider Agito to battle Agito's Evil Twin.
    • ZO and J fight a multi-seasonal batch of monsters in Kamen Rider World (8-minute theme park thingy, may not be canonical but never said not to be, and not contradicting anything) which puts all three hiatus movies (yes, Shin provided a monster) into old-school KR continuity. Kuuga's mention of a Professor Hongo (and an imitation of him, which means he must have known the Hongo) put Kuuga and Agito into it as well. However, Decade makes the multiverse more complicated with its alternate universes bearing variable resemblance to — and rarely literally being — the worlds of the actual series it's crossing over with. We even get Black and Black RX as separate worlds, as well as Kuuga and Agito, with alternate versions of some of the same people. Even more so, late in Double a member of Foundation X can be seen looking over data on OOO's Core Medals. Nothing came of this for over a year, until the crossover Kamen Rider X Kamen Rider Fourze And OOO Movie War Megamax revealed that Foundation X would be playing a role, this time using the Astro Switches from Fourze...and that Double and the first seven Showa Riders would be teaming up with Fourze and OOO. Given how Astro Switches are Gaia Memories this makes some sense (except for the Last One thing).
    • Some Decade worlds have versions of Riders of other worlds with no dimension-hopping. For example, Dark Kabuto, Dark Kiva, Ryuga, and Orga live in a world where monsters rule, and have no connection to Kabuto, Kiva, Ryuki, or Faiz. It's the second Ryuga we meet, and no, the first wasn't in the World of Ryuki, either.) It also means Double and OOO take place in the World of the Rider War, as Double does no dimension hopping to meet Decade, and OOO does no dimension hopping to meet Double in any of their multiple teamup occasions.
    • Decade's own Mind Screw-itiude and A Wizard Did It attitude makes it nigh useless for working out continuity issues or finally answering which of your favorite Riders can kick the other's ass. Post-Decade teamup occasions not requiring any dimension-hopping (as it was with pre-Decade teamup occasions) would seem to have all things Kamen Rider in one universe, with past Riders still out there after they leave our sight (like any character in any show who has been Put on a Bus.) It would seem that none of the AR Worlds were the one universe KR usually takes place in.
    • As closest anyone can figure, here's how the Kamen Rider multiverse seems to work: The Showa era Riders and the 3 intermediate Riders (Shin, ZO, and J) take place in a singular continuity, as we saw. The Heisei era shows from Kuuga to Kiva (plus most of their movies) appeared to each take place in their own continuity, so completely separate were they, with the notable exception of Kiva and Den-O (the second Den-O movie has the Kiva gang cameo, and Kiva himself joins in the final battle) and the possible exception of Kuuga and Agito (there's a reference, and there are a few points that take some Fan Wank to make fit neatly.) Decade takes place all over the multiverse, but the opening episode and and the end of Movie Wars takes place in the same continuity as Double (whose appearance in Decade's movie can be chalked up to his universe meshing with Decade's). And all of the series from Double onwards exist in the same continuity, which also contains variations of every Rider from Ichigo to Kiva, just not exactly as we saw them in the series. As far as OOO is concerned, his movies seem to be more canonical than his actual series is.
    • However, the more we see of Riders old and new it makes more sense to just toss Decade out: its "AR Worlds" are clearly not the originals, so the World of Blade that's like a workplace sitcom with Riders and the World of Ryuki that's like a legal drama with Riders being separate worlds tells us nothing whatsoever about the canonicity of the series that they resemble In Name Only. When it comes to the actual shows, the assumption made by fans that when Superman Stays Out of Gotham it means Metropolis and Gotham are in completely separate and unrelated universes is something that never had canonical support, and now that Riders meet all the time it goes from plausible Fan Wank to something that really doesn't have a leg to stand on.
    • However, don't put away your migraine medicine just yet: OOO, Den-O, All Riders: Let's Go, Kamen Rider would have the Decade World of Kuuga Big Bad instead of the Kamen Rider Kuuga Big Bad representing the Grongi in the Legion of Doom, which would have welded Decade and its madness right back in...if it weren't for the fact that the movie's ending implicitly makes the whole ordeal non-canonical to everything by virtue of settling on a Close-Enough Timeline where, in regards to Kamen Rider OOO, Hina doesn't know Eiji. (Also, every character who appeared in Decade had their updated design from that series instead of their original designs, but that can be ignored - you'd use the shiny Decade suits instead of making all new ones that don't look as good in order to perfectly match the 1970s versions.)
    • Let's Go, Kamen Rider also gives us cameos of Inazuman, Kikaider, Kikaider 01, and even Kaiketsu Zubat. So basically everything with Shotaro Ishinomori's name on it officially coexists now, even if you didn't take Goranger vs. JAKQ (which had Kamen Rider V3, Kamen Rider Amazon, and Kikaider stated to be fighting the same Legion of Doom overseas.) seriously before. Then one of the Kamen Rider Fourze movies goes and introduces Inazuman... based on Inazuman the manga, not the show, and so not the Inazuman encountered in Let's Go Kamen Riders.
    • And then Kamen Rider Gaim meets up with Kikaider. Namely, the version from Kikaider Reboot instead of the one we met in "Let's Go, Kamen Riders."
    • Masked Rider, the not well received American adaptation of Black RX, was launched with a Poorly Disguised Pilot in a Mighty Morphin' Power Rangers episode; much later, Power Rangers in Space crossed over with Ninja Turtles: The Next Mutation, which makes all three American series share a verse. All three are produced by Saban, which wasn't so bad back then, but as of 2009...
    • Take all the crossovers above, put two plus two with the Kamen Rider and TMNT multiverses separately established by Decade and Turtles Forever respectivelynote , and toss in both the canonical Samurai Sentai Shinkenger arc of Decade and Teenage Mutant Ninja Turtles: Smash Up for kicks. End result? Kamen Rider, Power Rangers, Super Sentai, TMNT, the Ultra Series, and Raving Rabbids are all part of the multiverse. It's gotten to the point that, near as anyone can tell of the yet-unreleased Kamen Rider X Super Sentai Superhero Taisen movie, nobody except Marvelous and Decade know what the hell is going on. Even the narrator is baffled. And with Compati Hero Series The Great Battle IV this would tie in Gundam, the Ultra Series, and Kamen Rider, et al. with the aforementioned Super Robot Wars and... well. Just let your imagination go wild, one supposes.
  • Transformers was split from its very beginning into separate comic and cartoon continuities. However, this rapidly splintered further and further, with different comics in different continuities being introduced, anime series being created, the introduction of the Beast Wars and Beast Machines ranges which combine elements from previous continuities, the live-action movies and so on.
    • In the mid-2000s, writer Simon Furman ruled that every single Transformers continuity forms part of a massive multiverse of different timelines, dimensions and universes, and sometimes featured crossovers in his stories (for example, the Generation One Galvatron and several others making a cameo appearance in a Transformers Armada comic). He also ruled that Unicron and Primus are constant forces in this multiverse, and though they can be destroyed in one reality their consciousness lives on in another. Curiously, his next range of comics for IDW seemed to separate from this idea altogether.
    • The canonical explanation of how multiversal singularities work, using The Fallen as an example, truly has to be read to be believed. Here's a link.
    • It gets better. Courtesy of Axiom Nexus, any Transformers series can interact with any other.
    • Even better, the Transformers franchise itself was an amalgamation of several unrelated lines of Japanese die-cast toys (Jetfire/Skyfire was a VF-1 Valkyrie), with most of the welding done by the fine folks at Marvel Comics and Sunbow Productions.
    • The Transformers also went full circle when they crossed over with the New Avengers. To say nothing of their participation in the Infestation crossovers at IDW, which suggests that, among others, Star Trek and the Teenage Mutant Ninja Turtles are also part of the same multiverse.
    • Regeneration One, the continuation of the original Marvel series (disregarding the Generation 2 series), concludes that the Grand Plan of Primus is to eventually create one "optimal" universe that comprises the best features of the various realities of the multiverse. And yes, Simon Furman wrote that series. (It also features a team-up of Rodimus Prime and his cross-dimensional counterparts.)
    • The Transformers and G.I. Joe often take place in the same universe. The G1 cartoon continuity also includes Jem, Inhumanoids, and C.O.P.S.; most of these series all had cameos from Hector Ramirez, an in-universe news reporter and a takeoff on Geraldo Rivera. My Little Pony 'n Friends was close to being in the same universe, due to My Little Pony: The Movie (1986) nearly including scenes where Firefly encounters Shipwreck of G.I. Joe (who was drunk) and Optimus Prime.
    • The Hasbroverse follows a similar premise, which also includes My Little Pony: Friendship Is Magic and Dungeons & Dragons. The author sets the G1 MLP as G4's distant past, and used some Broad Strokes by using mostly Marvel's G.I. Joe and having the G1 Transformers each possess a spark (a concept introduced in Beast Wars). The Earth Defense Command, meanwhile, is a descendant of both the original Joe Team and their Russian counterparts, the Oktober Guard; their respective leaders (General Clayton "Hawk" Abernathy and Colonel Ivan Brekhov) are now the leaders of the US and Russia, while Cobra got decimated in 1994 after an ill-advised attack on the Decepticons; only Cobra Commander and a few others managed to escape.
    • When a Matt Trakker figure was released as Specialist Trakker in one of the G.I. Joe toylines, M.A.S.K. was adopted into the G.I. Joe universe. (M.A.S.K. originally started as Kenner's counterpart to the Joes and the Transformers; it came under Hasbro's umbrella when tkey acquired Kenner Parker Tonka in 1991).
    • And Revolution not only welds together their Transformers and G.I. Joe comics into one universe (with the statement being that all the Joe issues took place during a time where the Cybertronians were absent from Earth), but also brings in rebooted versions of Rom the Space Knight, the Micronauts, Action Man and M.A.S.K.note , with all sorts of connections between characters and plot threads between everything - Miles Mayhem was a member of Joe Colton's Adventure Team (and founded M.A.S.K. as an anti-Cybertronian deterrent team, with parts of their technology reverse-engineered from their captive, Decepticon triple-changer Blitzwing), Colton himself was on of a few Joe Team members who got replaced by Dire Wraiths (Rom's sworn enemy), Baron Karza found that Microspace was created by Micronus Prime (one of the 13 Primes of Cybertronian lore), and Ore-13, a powerful energy source created by Decepticon Shockwave and seeded on Earth during the ice age, is what drives the plot, as everyone is trying to use it. It's eventually revealed that Mayhem, Karza and the Dire Wraiths were working together to exploit Ore-13 for their own ends, only for Karza to go One-Winged Angel when he absorbs a bunch of Ore-infused Wraiths with his "enerchange" ability and takes down Mayhem; it ultimately takes the Micronauts, Rom, Soundwave, Matt Trakker and Mainframe working together to bring him down.
    • The follow-up Revolutionaries takes it further, bringing in all sorts of obscure concepts and tying up dangling plot threads from previous IDW titles, including various G.I. Joe-related villains - Baron Ironblood from Action Force (the British 80s counterpart to G.I. Joe), General Krieger from Sgt. Savage and his Screaming Eagles (a mid-90s attempt to reboot the G.I. Joe line), Iron Klaw from G.I. Joe Extreme, and the Transformers from Hearts of Steel (a universe where the Transformers landed on Earth in the 1800s and got Steampunk bodies).
    • More toy lines related to the Transformers multiverse include GoBots, Robotix, Rock Lords, and Beastformers, the Japanese version of Battle Beasts.
  • Shotaro Ishinomori's later Skull Man manga incorporates his earliest concept for the titular character of Kamen Rider, monsters from said show, and Kamen Rider himself, along with appearances of Joe Shimamura from the anime Cyborg 009 and cameos from Himitsu Sentai Goranger, Robot Detective, Inazuman, and Kikaider. A later anime version of Skull Man has a Downer Ending that connects it even more explicitly to Cyborg 009: Skull Man is defeated and turned into Black Ghost, the Big Bad of 009.
  • The Cyborg 009 graphic novel by Archaia showed background references that implied Skull Man and Kikaider were part of the same universe. The last issue took it even further, revealing that Black Ghost was funded by Foundation X from Kamen Rider Double. Archaia had plans to make a massive Shared Universe comic series out of Ishinomori's works, but that fell through when Ishimori Pro disagreed with the direction the series was taking and the whole thing stalled out.
  • The OVA Giant Robo: The Day The Earth Stood Still and its companion manga The Day The Earth Burned incorporates practically all of Mitsuteru Yokoyama's work, including the first magical girl Sally the Witch, the tokusatsu show Iga No Kagemaru, the eponymous giant robots, and historical characters from both the Water Margin and Romance of the Three Kingdoms.
  • Inverted with Starship Titanic and The Hitchhiker's Guide to the Galaxy. Despite both featuring similar Starship Titanics which undergo similar events in similar settings, the game explicitly states that they're different universes.
  • Witch Girls Adventures is a 'verse created almost entirely through Canon Welding. The 'verse started as a fetish e-zine called "The Shrinking Sorceress" by MANGA GRAPHIX, dedicated to sorceresses transforming people into animals and inanimate objects. Later on, many of the same people went on to write Witch Girls Tales, theoretically a comic about young witches getting into mischief with their powers, and several characters and concepts from MANGA GRAPHIX stories ended up in the new 'verse. Completely independently, a different author wrote a comic called "Princess Lucinda," about the titular princess' love for wickedness and transforming people over the slightest offense. The Witch Girls Adventures game was created as a team-up between Channel M (the reconstituted MANGA GRAPHIX) and Abby Soto (the creator of Princess Lucinda), using characters from "The Shrinking Sorceress" (including some that hadn't yet appeared in Tales), Witch Girls Tales, and Princess Lucinda all in a single standalone universe.
  • Return to Labyrinth:
    • The OEL manga sequel to the film Labyrinth has cameos by Uncle Traveling Matt from Fraggle Rock and the devils from the "Soldier and Death" episode of The Story Teller, establishing that these Jim Henson Company works share a Verse.
    • Fraggle Rock (the location) is basically a canon-welding tool, since it's established in the fourth season of the show that the Rock can magically link to many locations - some in our world, some in others. Uncle Matt also turned up in The Muppets Take Manhattan, and other creatures from the Rock have appeared as extras in Muppet productions throughout the 1990s. In turn, the Muppets share a universe with Sesame Street. Additionally, one creature occasionally seen in Fraggle Rock resembles Fizzgig from The Dark Crystal, suggesting another link.
  • The Soul Series is confirmed by Word of God to take place in the distant past of the Tekken universe due to the presence of Yoshimitsu in nearly every installment of both series (the Soul series Yoshimitsu didn't debut until Soulcalibur, and he is eventually succeeded by Yoshimitsu the Second in Soulcalibur V). The presence of The Legend of Zelda, Star Wars, God of War, Image Comics, and Assassin's Creed characters are non-canonical (although Lizardman's character profile in SCV seems to imply that he ate Kratos). As for Tales of Symphonia and Sgt. Frog, it's left ambiguous.
  • Video game Blair Witch Volume I Rustin Parr sets the original Blair Witch movie and the video game Nocturne, made by the same creators, in one world. And apparently the first BloodRayne game implies several times that it's set in the same world as Nocturne.
  • Dungeons & Dragons:
    • There is a crossover between Wonder Woman and Fafhrd and the Gray Mouser. The latter's world was adapted into D&D setting. Of course, there was a fair amounts of retcons in The DCU and revised editions of D&D, but it's quite possible that the link establishing connection between the three still exist in some form.
    • Thanks to the d20 edition of Call of Cthulhu you can play as Dungeons and Dragons characters in Call of Cthulhu and introduce the Cthulhu Mythos into Dungeons and Dragons. It however doesn't stop there as the Call of Cthulhu sourcebook known as the Malleus Monstrorum not only mentions every major Mythos entity, it also manages to throw in The Thing (1982), the Martians of The War of the Worlds, and The Wicker Man (1973) and several of Stephen King's characters as avatars of Nyarlathotep.
    • D&D's crossover with the Mythos and Nehwon goes back to the AD&D 1st Edition version of the Deities & Demigods Sourcebook published in 1980, along with the heroes of Arthurian legend and the deities of Michael Moorcock's world of Melnibone. The Cthulhu Mythos and Melnibonean material nearly brought down legal action from Chaosium, which had the game license rights to both at the time, and so they were left out of subsequent print runs since TSR didn't want to provide a reference to a competitor in the publishing credits. Obviously, copies of this first printing are hard to find.
  • Raymond E. Feist's The Riftwar Cycle, set in Midkemia, setting of RPG publisher Midkemia Press, who were also Raymond E. Feist's college role-playing buddies. note  The Riftwar Cycle includes Sierra's Betrayal at Krondor and its novelization.
  • Neil Gaiman's American Gods had a cameo from Delirium of the Endless from The Sandman. Given the Endless' nature it is entirely vague if that means the book takes place in the DC Universe or just is part of the same multiverse.
  • Team Four Star connected their Let's Play of Dragon Ball Xenoverse to Dragon Ball Z Abridged by way of Ascended Fanon: namely, that their character Dumplin is a younger, less experienced Mr. Popo.
  • Disney Parks' The Society of Explorers and Adventurers is this trope in a nutshell. What started as a way to retheme the Tokyo DisneySEA's version of the Tower of Terror has proceeded to be a franchise tieing together Hong Kong's Mystic Manor, and Magic Kingdom's Jungle Cruise and Big Thunder Mountain Railroad. What separates it from the Thunder Mesa in Disneyland Paris (mentioned in the Theme Parks section below) is the numerous easter eggs hinting that it's taking place in the same universe as Indiana Jones, ultimately confirmed with the Jock Lindsey's Hangar Bar in Disney Springs confirming the eponymous pilot was a member of the Society.

    Anime and Manga 
  • Manga creator Go Nagai does this often with his various works, although Mazinger Z and UFO Robo Grendizer were already part of one continuity from Grendizer's get-go.
    • Shin Mazinger is quickly reaching a critical level of this, with a woman from Violence Jack turning out to be Kouji Kabuto's mother.
    • Violence Jack has incorporated Devilman and later Devilman Lady as taking place in one Universe that resets itself and all main characters are really incarnations of Akira Fudou. And because the series is also Deconstructor Fleet for all other Go Nagai's manga, there are many theories incorporating them into it in all incarnations, which is possible thanks to the nature of this world. Cameos and crossovers between his works are so often it's pretty easy. Then there's Devilman Grimoire, where Jun Fudo and Aoi Kurosaki from Devilman Lady are shown to be teachers at Akira and Miki's school. They are also lovers. Alphonse and Himura, from the 1970s Devilman anime series, also feature.
  • Gosho Aoyama's three main works Detective Conan, Magic Kaito, and Yaiba!, have the tendency to merge into one universe. Magic Kaito was more or less put on hold in favor of Detective Conan, but its characters occur so frequently in Detective Conan to be the latter's recurring characters. Although, Aoyama also drew the line: Detective Conan does not deal with the daily life of the Magic Kaito characters.
  • The Gundam franchise started off with only the Universal Century timeline under the auspices of creator Yoshiyuki Tomino. When he stepped away from the franchise in 1993, Sunrise introduced the concept of Alternate Universes to allow new creators to explore their vision of Gundam without creating a Continuity Snarl, resulting in the Future Century, After Colony, and After War timelines. Then Tomino returned for the 20th anniversary and created ∀ Gundam, set in the Correct Century timeline, which was eventually revealed to be the Distant Finale of all of Gundam, including the AUs. Afterwards came more Alternate Universes (Cosmic Era, Anno Domini, Advanced Generation, and Post Disaster), with Word of God confirming that they're part of the timeline created by Turn A as well. Tomino's latest work, Gundam: Reconguista in G, takes place in the Regild Century timeline, which is explicitly stated in-series as being the era that came after the end of the Universal Century. The sole exception to the rule is Gundam Build Fighters, which takes place in a 20 Minutes into the Future setting where Gundam is a popular anime franchise. Presumably the same applies to Model Suit Gunpla Builders Beginning G, which is Build Fighters' spiritual precursor.
  • The mangaka group CLAMP has been known for self-crossovers for many years, but their twin series Tsubasa -RESERVoir CHRoNiCLE- and Xxx HO Li C are meant to tie all their works—both present-day and fantasy—into a single continuity.
  • Pretty Cure All Stars. 14 magical girls from 4 different continuities save the day. Awesome.
    • The second All Stars-movie features 17 magical girls from 5 different continuities. From the previews it seems to feature some of the different baddies, too.
      • All Stars DX 3 ups the number to 21 from 6 continuities and the brand-new New Stage brings it to a grand total of 28 from 7. It overlaps with Remember the New Guy? as a lot of Cures that show up in one movie weren't in the movie before that.
      • All Stars New Stage delivers a Retcon of sorts now stating that 23 magical girls from 6 different continuities saved the day. Then 5 more from the 7th hopped in and it was madness.
    • Interestingly, it seems that Smile Pretty Cure! is attempting a bit of a Canon Weld experiment themselves - an episode midway through reveals that Yayoi's mother works for Fairy Drop, the store owned by Erika Kurumi's mother. And said mother is mentioned, at least by last name.
  • Eiichiro Oda re-used Ryuuma, a character from his one-shot manga Monsters, as a (zombified) villain in One Piece and his home country was mentioned to be part of the New World (the second half of the Grand Line). He later confirmed that Monsters was incorporated into the backstory of the setting.
  • Mahou Sensei Negima! reveals that all of Ken Akamatsu's major works exist in the same universe. The ties between Negima and Love Hina are obvious with Setsuna being a Shinmeiryuu swordswoman, which is lead by the Aoyama family from Love Hina; the reference to A.I. Love You is found in a single panel, although it's kinda important, as the protagonist of that series is implied to have written the code that enables Chachamaru to have a soul.
  • Dragon Ball:
    • Before he gave the world Dragon Ball, Akira Toriyama's first popular series was a comedy called Dr. Slump, about a robot girl and the slob scientist who created her causing havoc in a weird place called Penguin Village. About a year into the Dragon Ball series, Toriyama had Goku visit Penguin Village and meet most of the Slump cast, thus joining the two series into one universe. This was mostly done as an attempt to use Dr. Slump's popularity to help increase readership of Dragon Ball, as it wasn't the huge hit it would eventually become yet. In contrast, the crossover has had the opposite effect in later years: many fans, especially outside of Japan, only know the Dr. Slump cast because of their guest spot on Dragon Ball. It's gotten to the point that Arale's made it into at least three Dragon Ball video games as a playable character! Dragon Ball Z: Budokai Tenkaichi 3, Dragon Ball Origins and Revenge of King Piccolo, to be precise. The first one also caused a good amount of rejoicing for those who knew her.
    • The Akira Toriyama manga Pola and Roid, Tomato, Girl Detective and Wonder Island connect to Dr. Slump through cameos. The manga Dub and Peter 1, Escape, Go! Go! Ackman, Kajika, Kintoki, Nekomajin/Nekomajin Z, and Sand Land might all take place in the Dragon Ball universe (Galactic Patrol of Jaco the Galactic Patrolman, Jiya and Sachie-chan Guu!! fame is confirmed to take place due to its ending).
    • Dragon Ball Super is an odd example, since while it's specifically meant to be a sequel to the original Dragon Ball manga rather than the anime, various anime-only Filler moments get directly referenced. Gregory, an anime-only character, is present, Android 18 gets pissed when 17 accidentally calls Marron "Maron", Krillin's girlfriend from the Garlic Jr. filler arc, and when Krillin is surrounded by ghosts of the various villains they've fought over the series, Captain Ginyu in Bulma's body also appears, something that also never happened in the manga. On the other hand, Gohan at one point talks to a group of bus hijackers he stopped in the manga, but not the anime, and various continuity errors, such as the different depictions of hell in the Z anime and Super exist if one tries to connect them directly.
  • The canons of Tsukihime, Fate/stay night (plus others) are generally grouped together and called the Nasu Verse. There's rarely direct crossover of the characters, except in spin-off games and non-canonical side-comics. Word of God on each canon's characters respective power levels in relation to each other (can Shiki kill Servants?) is conflicting. Even better: it is canonical in the series that alternate timelines exist in which different events took place, and that travel between them is possible (albeit extremely difficult, this being the Second Magic), so it can be said that all routes of all materials are canonical in one universe or another. Except Kara no Kyoukai which, by Word of God, explicitly isn't in the same universe as Tsukihime.
  • Leiji Matsumoto is notorious for this, with Galaxy Express 999, Captain Harlock, Queen Millennia, and Space Battleship Yamato crossing over to various degrees, not always following a consistent continuity.
  • Endings of Getter Robo Armageddon and New Getter Robo in which Armageddon versions of Ryoma, Hayato and Benkei and New version of Ryoma ends in Warrior Heaven, alongside countless Getters, fighting unknown monsters has hinted that all Getter's separated continuities (two mentioned above, Ken Ishikawa's manga continuity, Getter Robo DASH manga and anime Getter Robo Go and Shin Getter Robo Vs Neo Getter Robo) might exist in the same Multiverse.
  • Madhouse Studios anime adaptations of four Marvel Comics' titles - X-Men, Iron Man, Wolverine and Blade - are set in one Universe, confirmed both by Word of God from Marvel and the same Wolverine appearing in all four anime.
  • GaoGaiGar FINAL has blink-and-you'll-miss-it cameos of characters from Betterman, establishing those two series takes place in one Universe.
  • REDLINE does this by making main characters from two different anime - Miki and Todoroki from Mole Brothers and Trava and Shinkai from Trava First Planet - participating in the eponymous race.
  • Several years ago, Hidenori Kusaka and Satoshi Yamamoto worked on a short Pokémon Ranger manga that was only released online. As it turns out in the Platinum arc of Pokémon Adventures, the events that occured in that online comic are indeed canonical. The Ranger story was later included in an Adventures art book.
  • Time Bokan:
    • Yatterman Night has the cast encountering characters (or in some case, blatant Expies)) from various other shows produced by Tatsunoko Production. One episode even has Galina and Alouette driving the Mach 5!
    • This seems to be tradition for Yatterman: the original and 2008 series crossed over with several Tatsunoko shows, and even placed them in a "Tatsunoko Kingdom" where all Tatsunoko characters appeared to reside in during one OVA.
  • Eiji Ohtsuka has demonstrated that his horror manga MPD Psycho and The Kurosagi Corpse Delivery Service share a continuity thanks to the character Sasayama, who appears as a police officer in the former and as a social worker, at a later stage of his life, in the latter.
  • Before High School D×D, Ishibumi wrote the first iteration of SLASHDØG which flopped and never went past the first volume. However, he did bring in Tobio Ikuse first as a Canon Immigrant in Volume 15 on 2013, a year later he went at rewrote SLASHDØG and properly placed in the same universe as DxD, birng along Grauzauberer and Akeno's extended family and properly developed it into The 'Verse by adding a character from his first and most obscure work, Denpachi.

    Comic Books 
  • The DC and Marvel universes were born from this trope; originally, the titles published by each company did not overlap, but over time, cameos, Crossovers, and inside references combined to form the comic books into one big, interconnected web. That's not even counting the Amalgam universe. Since DC Vs. Marvel in 1996, it's revealed all crossovers were canonical — From a Certain Point of View. note 
    • Mind, Marvel started this with the first issue of Spider-Man. And even before that, Marvel started this 21 years earlier in the Timely Comics era, when Human Torch faced off against Namor the Sub-Mariner for the first time. They teamed a few more times over the next few years, and some of the less prominent characters occasionally got involved. Then, in 1946, Timely launched the All-Winners Squad, teaming up existing characters like Captain America, the Human Torch, and the Sub-Mariner (among others).
    • DC started it in All-Star Comics #3 with the Justice Society's first meeting. To this day, it's generally accepted that the Justice Society is the first-ever example of a super hero team lasting longer than a single issue in comics history.
    • DC has also historically made a habit of assimilating the characters of other comics companies into their multiverse - Quality Comics (Uncle Sam and the Freedom Fighters, Plastic Man, Blackhawk), Fawcett Comics (Shazam, Captain Marvel and the Marvel Family), Charlton Comics (Captain Atom, Blue Beetle, The Question), Wild Storm (The Authority, Wild CA Ts), Milestone Comics (Icon, Hardware, Static) and Archie Comics' Red Circle superhero characters. Generally, these characters start off in alternate universes, and then some sort of universal crisis reboots the DC Universe yet again, merging the universes. That said, sometimes the welding isn't permanent, as with the Red Circle characters, who eventually returned to Archie.
    • DC Rebirth saw the welding of Watchmen and the DC multiverse.
    • Interestingly, it's suggested that they are all interconnected through... X-Men. The final issue to the 1996 comic series X-Men Adventures, which is set in animated universe, revealed that that universe was the universe that gave way to the main Marvel Universe (thus making Galactus a Canon Immigrant retroactively). Even more, the Living Tribunal is shown watching the creation of this world, temporarily holding back the brothers who would cause the aforementioned DC vs. Marvel event and even mentions needing to talk to his his hooded spectorial counterpart.
  • Shazam and Kid Eternity are a particularly interesting example. DC acquired the rights to both from separate comic companies. Eventually, they realized that Shazam's Freddy Freeman and the nameless Kid had remarkably similar back stories—both were raised by a grandfather who died in a boating accident caused by Nazis, which also resulted in the grandson getting superpowers activated by saying a magic phrase. As a result, Freddy and "Kit Freeman" were revealed to be brothers.
  • Image Comics is an interesting case.
    • Originally, all of its titles took place in a shared universe. Over time, the original Image partners focused on their own corners of the Image Universe, causing the continuity to split into several distinct sub-continuities. The Shattered Image crossover made the split official. But Image partners still occasionally "borrowed" each others' characters, so the sub-universes still interacted. As new, non-partner creators become more prominent in Image Comics, they started building universes of their own, and they occasionally used the Image partners' characters. For example:
    • Characters from Jay Faerber's creator-owned series (Noble Causes, Venture, Firebirds, and Dynamo5) appear in each other's books all the time, creating a loose-knit "Faerberverse".
    • Robert Kirkman's characters occasionally cross over in a similar fashion (and sometimes become supporting cast - especially in Invincible). The Kirkmanverse and Faerberverse intersect at a number of points, especially The Pact mini-series. Other Image characters, such as Savage Dragon and Shadowhawk, often pop up. Spawn didn't make an appearance until Image United, which brought together characters of all of the current Image partners (Erik Larsen, Rob Liefeld, Todd McFarlane, Marc Silvestri, Robert Kirkman, and Jim Valentino), as well as Whilce Portacio and several other creators.
    • Angela from the Spawn universe jumped ship to the Marvel Universe at the close of Age of Ultron.
  • Eclipse Comics' four-part crossover mini-series Total Eclipse brought together virtually all company-owned and creator-owned characters that the company published.
  • 2000 AD:
    • The Harlem Heroes strip (about a basketball team with jetpacks in 2050) appeared to be totally unconnected to the 22nd centuy of the Judge Dredd universe until the son of one of the Heroes (John "Giant" Clay) joined the Judges (as Judge Giant).
    • The Judge Dredd story "Hammerstein" suggested ABC Warriors was also set in the past of the Dreddverse, but later ABC Warriors stories contradicted this.
    • Judge Dredd has also had crossovers with other 2000 AD strips whenever the writers felt like it, most notably Strontium Dog and the story Helter Skelter (where Garth Ennis basically crossed ALL his favourite strips over with Dredd).
    • Meanwhile, 2000 AD stalwart Pat Mills has crossed over everything he's ever written for 2000 AD with each other. Invasion!/Savage, Flesh, Ro-Busters, ABC Warriors, and Nemesis the Warlock all slot together.
    • Ian Edginton does the same thing with his 2000 AD strips: both Stickleback and The Red Seas share a secret organisation, little mentions and character cameos abound, and the same brand of monster appears in Stickleback, Ampney Crucis Investigates, and Detonator X.
    • Even more Edginton crossovers: Sir William Ashbless, immortal designer of the titular ship in Leviathan made a cameo appearance in Stickleback and his shipping company, White Hart Line, got name dropped in Ampney Crucis Investigates. Also a few locations have been repeated across the various strips at different periods in history.
    • John Smith did a similar thing from the start in order to make his stories stand out: all his initial Future Shocks linked in to an organisation called Indigo Prime, and a couple of Indigo Prime agents also appeared in Tyranny Rex. Indigo Prime then got its own series, and eventually crossed over with Smith's Vertigo Comics series, Scarab.
  • Alan Moore:
    • He, as time has gone on, has turned The League of Extraordinary Gentlemen into this, making vague references to the source material for Ozymandias and The Black Freighter. Oh, sure, it's only references to the inspirations for them, and Moore would probably rather have his skin boiled than actually go further than that, but this is Alan Moore, there are no coincidences. As an aside, Moore is a close friend to Moorcock, close enough that Moorcock has allowed Moore to put in some Moorcock characters into the League series free of charge.
    • Back in the day, Alan Moore sketched out a unified Warrior timeline, the most notable aspect of which was that, in an Alternate Universe where Micky Moran never regained his memories and powers, Emil Gargunza went on to build Fate, Norsefire's supercomputer. The timeline also established when all the "centuries in the future" strips happened in relation to each other, and introduced the Chronarchs, who Moore calls "Earth-2 Time Lords", and who seem to be based at least partly on his own version of Gallifrey in the Doctor Who Magazine comic strip. Then Moore quit Warrior and the book collapsed before any of this could actually appear.
    • Moore's Providence is an attempt to do this for all of H. P. Lovecraft's stories, or at least the different cycles. Much like League of Extraordinary Gentlemen, Moore is using Lovecraft's fiction to merge different stories and events into a single coherent verse. This includes "Cool Air", "The Horror at Red Hook", "The Shadow Over Innsmouth", "The Dunwich Horror", "The Colour Out of Space", "The Dreams in the Witch House", "The Thing on the Doorstep".
  • Frank Miller's Batman stories: Batman: The Dark Knight Returns, Batman: Year One, The Dark Knight Strikes Again, and All-Star Batman and Robin were originally supposed to be in separate universes, with only Batman: The Dark Knight Returns and The Dark Knight Strikes Again having any clear continuity with each other.
  • This article suggests that all of Mark Millar's later Marvel works (1985, Fantastic Four, Kick-Ass, and Old Man Logan) is all interconnected. (Three of those are automatically canonical to each other anyway, of course, but Kick-Ass is more of a surprise.) Even ealier Millar established connections between three comics published by different companies - Wanted, Chosen and The Unfunnies. The reason why at the end of Chosen the media doesn't report the Antichrist's miracles is that they're controlled by supervillains from Wanted. And Troy Hicks from Unfunnies helped Satan rape the Antichrist. Never published Run! was supposed to be set in that world too.
  • Grant Morrison's All-Star Superman and DC One Million seemed to be tied in the same continuity.
    • Of course, Grant Morrison is one of the architects of Hypertime (the other being Mark Waid) which posits that it is all true. Under this concept, the events of DC vs. Marvel exist somewhere in continuity.
    • Almost all of Morrison's DC works are tied to each other, as well to the real world, forming a big "Morrisonverse". Here's how it goes: In All-Star Superman Superman creates the infant universe Qwewq. In JLA we see the heroes discover (a version of) Qwewq. Both in ASS and in JLA: Confidential we see that Qwewq actually contains "our" Earth, i.e. a realistic Earth with no superheroes. The final Morrison-penned issues of Doom Patrol and Animal Man take place in a realistic world with no superheroes (and they both share the same colour scheme, meaning it's the same world in both), which is presumably Qwewq, i.e. "our" world. In Seven Soldiers we find out the ultimate fate of Qwewq (or at least one version of it). Final Crisis (which takes place in the same universe as JLA) refers to Bleed (the "sea" that separates different universes in the DC multiverse) as "ultramenstruum", and the same term is used is The Invisibles, implying that the Invisibles universe is a part of the larger DC multiverse. If we accept that Qwewq is "our" universe, this means our universe exists inside a larger universe populated by superheroes. Both Flex Mentallo and The Filth feature the "real" world to which superheroes from outside this world burst in; thus, the real world in both these comics could be (a version of) Qwewq. And then a huge chunk of the Damian Wayne stories written by Morrison that take place in the not too distant future were revealed to be set in the past of DC One Million and ends with Damian training Terry McGinnis from Batman Beyond to become his successor. Lastly it also seems that DC One Million takes place in the future of All Star Superman as Solaris and Kal Kent appear and happens to be the story of how Superman ended up having to fix the sun. To sum it up, almost all of Morrison's major works for DC are welded together, though admittedly some of the links between them are vague.
  • When Semic Comics, a French comic publisher, decided to revive the characters it inherited from defunct Editions Lug, editor Jean-Marc Lofficier set out to link over 2000 largely unrelated characters from just about every comic book genre into a single continuity. Some characters had to be revamped fairly drastically to fit in, and a few had to be revamped to avoid duplication.
  • In Non Sequitur, Wiley frequently used four separate sets of recurring, originally nameless, characters: a silent Everyman who'd observe some of the comics' less absurdist strips, a Leisure Suit Larry-ish barfly, a snarky Bratty Half-Pint girl and the Sunday-only diner owner "Offshore" Flo (and her tall-tale telling patron, Eddie). Gradually, the characters started interacting: the Everyman and the barfly were seen hanging out at the bar, the girl and Flo would occasionally be seen reacting to something from the Everyman's radio talk show. Eventually, Wiley brought all these elements together to form a central cor: Joe (the everyman) and Bob (the barfly) are brothers, Danae (the little girl) and her little sister are Joe's daughters and Flo is Joe and Bob's mother. Eddie remains "just" Eddie.
  • In one Super Special Archie Comics' Sonic the Hedgehog, Sonic finds himself universe hopping to the Sonic Underground universe. In the 25 Years Later storyline, he names his children after his counterpart's siblings.
  • The villain of Asterix and the Magic Carpet briefly refers to his cousin Iznogoud.
  • One issue of PS238 reveals that it and Nodwick are set in the same world, though taking place in different "Heroic Ages."
  • 2017's The Scream and Misty Special did this in a couple of strips. Maxine in The Return of Black Max passes by the Sentinels from The Return of the Sentinels, and the title character of Death-Man encounters aged versions of classic Fleetway characters Leopard from Lime Steet, Pete's Pocket Army, Deathwish, Steel Commando, Paddy McGinty's Goat, Doctor von Hoffman, the Iron Major, and The Dwarf, as well as the successors of Doctor Sin and Thunderbolt the Avenger.
  • This is the crux of the plot for RoboCop Versus The Terminator: the technology that turned Alex Murphy into RoboCop leads to Skynet gaining sentience and the creation of the Terminators.
  • Street Fighter vs. Darkstalkers establishes that the cast of both series shares the same continuity. For instance, Kolin is revealed to have gained her powers after slaying an ice werewolf.
  • Garth Ennis' characters seem to coexist in a single unified verse, with characters from Hitman (1993) being referenced in The Punisher MAX or Cassidy from Preacher showing up in The Boys.
    • His run on The Punisher can be divided into two 'verses: the Marvel Knights one set after the "Angel Punisher" Dork Age where superheroes exist and regularly get in Frank's way, and the MAX universe that's basically our world but crappier (superheroes don't seem to exist and Nick Fury is an operative who started in WW 2 with no explanation for why he never ages). However, villains from the first verse (the Russian and Elite's son) made cameo appearances in the MAX continuity.

    Fan Works 
  • Haunted Mansion and the Hatbox Ghost: The fanverse includes several properties (fanmade and official alike) welded together into a single continuity, even when no continuity was intended from the authors.
  • The Slayer Prophecy has a few of these, mostly explaining how the Buffy cast can be part of the wider DC Universe and still have spent so long acting alone;
    • It is explicitly stated that the Hellmouth deflects external interest, which is why none of the major superheroes of the DC Universe have visited the city before.
    • Rack apparently fought Doctor Fate in the past before Rack and Fate disappeared from the public view.
    • Spike observes that Dala and the Monk were members of the Order of Aurelius, with the Monk just a little bit younger than the Master was at the time of his death.
  • In Harry Potter and the Mystic Force, it is established that Harry Potter and Power Rangers exist in the same universe (and in a reality where the Rangers battled Ivan Ooze as well as apparently all other televised continuity still being valid); no reference is made to other Hogwarts students being aware of past Rangers, but this can be attributed to the wizarding world’s stereotypical ignorance of muggle activities.
  • In Tara Sheppard, after Tara McClay meets her half-brother John Sheppard and learns about his work with the SGC, after analysis of Tara's DNA provides the means for the Asgard to cure their genetic degradation, Thor provides a full history of how demons fit into what the SGC know of Earth’s history.
  • Finmonster's The Marvelous World of DC and its sequels has an abundance of this;
    • Krypton is destroyed by Galactus, and Kal-El's landing is investigated by the Men In Black (to the point that Agent K is regarded by Clark as an uncle).
    • Thor is sent to Earth to be raised in an amnesic state on Paradise Island, which hides his true heritage until the time is right, to the extent that he considers Diana his sister as a child.
    • Hellboy comes to Earth on the same night that Captain America 'dies', and it is later established that his 'father' is Trigon the Terrible (with Raven, his half-sister, being raised as his daughter when she is born a few decades later).
    • The BPRD now includes Zatanna, John Constantine, Jason Blood/Etrigan, Detective Chimp, and Stanley Ipkiss/The Mask (the Mask itself being a creation of Thor's brother Loki).
    • The Nova Corps are basically a 'spin-off' of the Green Lantern Corps (Sinestro compared them to second-stringers, but considering his nature anything he says must be taken with a grain of salt).
    • The Ghost Rider is now an agent of the Spectre (who went rogue at some point prior to the series).
    • The Sentinels of Magic include Albus Dumbledore, Doctor Fate, Doctor Strange, Madame Xanadu, the Enchantress, Shazam, and Agatha Harkness.
    • Peter Parker, Jimmy Olsen, Garfield Logan, Virgil Hawkins, Johnny Storm and Victor Stone were all at high school together before most of them received their powers (or had to get their 'powers' in Vic's case) in the same accident, while the Fantastic Four, the Hulk and Firestorm were created in another event
    • Raven and Wanda Maximoff attend Hogwarts with Harry (and Constantine and Zatanna are also Hogwarts alumni).

    Films — Live-Action 
  • Present in horror films a long, long time. In the Universal Horror series, Frankenstein Meets the Wolf Man triggered the tendency to pile on the monsters, insisting that Dracula, the Wolf Man and Frankenstein's Monster all existed in a common universe. This does not work well with continuity (The Wolf Man takes place in the present day while the others happen in a dimly-characterized past), but they didn't care much by that point (Universal's horror films of the 40s are strikingly dumber and more juvenile than those of the 30s).
  • Predating even these examples: Fritz Lang's The Last Will of Dr. Mabuse (1933). Nominally a sequel to Lang's Dr. Mabuse, the Gambler (1922), it also incorporates Inspector Lohmann from M (1931) as the main protagonist. Blending the super villain from a pulp thriller with the hero of a police procedural works surprisingly well. Well enough that a 1960s revival of the Mabuse series retains Lohmann as its protagonist.
  • In all honesty Alien and Predator were never really meant to part of the same universe. The Xenomorph head seen near the end of Predator 2 was only meant as a reference to the non-canon comic book series that was being worked on at the time. It wasn't until the connection was made completely canonical in AVP: Alien vs. Predator. Hints placed by Ridley Scott in Prometheus and in the latest re-edit of Blade Runner suggest that they (and of course the rest of the Alien franchise, and transitively Predator) share the same continuity.
  • Toho's giant monster movies Godzilla (1954), Rodan (1956) and Mothra (1961) were originally standalone films about unrelated monsters, but they all gradually became part of the loosely defined Godzilla universe over time. The crossover film Mothra vs. Godzilla was the first step, but the mega-crossover Ghidorah, the Three-Headed Monster took it a step further when Godzilla and Mothra teamed up with Rodan against King Ghidorah, and Destroy All Monsters took it Up to Eleven when it threw in Manda (from Atragon), Baragon (from Frankenstein Conquers the World), Varan (from Varan, the Unbelievable), and Gorosaurus (from King Kong Escapes). Two Continuity Reboots later, the series' Grand Finale Godzilla: Final Wars also worked in Gezora (from Space Amoeba), and even the Godzilla from the 1998 American remake—who promptly got his butt kicked by the real Godzilla.note 
  • Full Moon Features also has done this a lot over their existence. Complete with direct Crossover like Dollman vs Demonic Toys, characters cameoing in other movies and to the point The Gingerdead Man is now a regular recurring character in the Evil Bong series now that his series is done. Ironically there also was Puppet Master vs Demonic Toys which while originated by Full Moon was licensed out and made by Syfy, which Charles Band now counts as non-canon both to the studio and the series.
  • And besides all the above, other crossover horror films such as Freddy vs. Jason, Sadako vs. Kayako and Lake Placid Vs Anaconda are all further examples.
  • Quentin Tarantino has created a largely common universe of his films by including subtle crossreferences (for instance, characters commonly refer to others; Mr. White mentions Alabama and Mr. Blonde has Scagnetti as a parole officer, Vic Vega and Vincent Vega are brothers, etc.) and cameos, but he says that his movies are divided into two universes.
  • An interesting example occurs with the Cloverfield franchise, which ended up having to be welded to itself. The first film was a standalone found-footage movie, and despite numerous Sequel Hooks, nothing came of them for a very long time. The next time the series' name showed up was 10 Cloverfield Lane, a film which had practically nothing to do with the original and felt very much In Name Only; rather than a found footage film, 10 Cloverfield Lane was a psychological horror film, and dealt with a human villain and an alien invasion rather than a giant monster attack. Wild Mass Guessing abounded on how these two films actually connected. It wasn't until the third film, The Cloverfield Paradox, that the true relationship between entries becomes clear; said film also serves as a prequel to the original Cloverfield, and sees Clover itself (or another member of the same species) appear at the very ending.
  • The 1980s/90s series of Superman and Batman films made no reference to each other and given their vast differences in tone might have been assumed to take place in very different universes (despite their comic books having long been from the same universe), until Bruce mentions that the circus Dick had performed with "must be halfway to Metropolis by now" in Batman Forever. That didn't prove it for everyone, though (Metropolis might just be another city in Batman's world, die-hards argued); it wasn't until the next movie that the canon welding was made official, in the most cringe-inducing way possible.
    Robin: (checking out the Batmobile) I want a car. Chicks dig the car!
    Batman: (turning to camera) This is why Superman works alone.

  • The ninth Fighting Fantasy gamebook, Caverns of the Snow Witch, took the player on a tour of the major locations from two of the previous books (Warlock Of Firetop Mountain and Forest Of Doom), establishing that they all took place in the same land of Allansia. (It also name-checked a character from Forest of Doom.) The monster manual Out Of The Pit then expanded this world: Allansia and The Old World, the setting for the Sorcery series of gamebooks, were two continents on the world of Titan.

  • Fantasy author Michael Moorcock gradually connected almost every single character he'd created into a Myth Arc revolving around the concept of the Eternal Champion.
    • Moorcock's Doctor Who novel The Coming of the Terraphiles features a Captain Cornelius, who may or may not be another aspect of the Eternal Champion (much like Jerry Cornelius) which ties the Eternal Champion into the Whoniverse as well!note  There's also a Second Aether, referencing Moorcock's Second Ether sequence which also takes place in the Eternal Champion continuity.
    • Moorcock also wrote some stories set in Alan Moore's America's Best Comics Universe, characters from which later appeared in Elric comics; Elric himself briefly met Conan the Barbarian in an early issue of Conan's Marvel Comics series.
  • Isaac Asimov: In the 1980s, Dr Asimov wrote several novels linking his Robot Series with his The Empire Trilogy and Foundation series. Foundation and Earth holds the most welding; a protagonist from Foundation's Terminus meet with a Robots protagonist, Nemesis is implied to be the ancestor story of another protagonist, and they describe the climax/collapse of an organization from The End of Eternity, implying that these stories all exist in the same continuity.
  • The final novels in Anne Rice's The Vampire Chronicles tie Lestat's story into that of The Mayfair Witches.
    • Actually, they were tied together much before that, notably by the Talamasca (introduced in Queen of the Damned and later a key player in both the vampires and witches novels) and a few common supporting characters like Aaron Lightner. In other words, the Witches novels avowedly take place in the same world as the Vampire Chronicles from day one, though their interactions increase substantially over time. Hints in The Vampire Lestat also indicate that Rice's least-liked novel, The Mummy, also shares a continuity with these series.
    • The novel The Queen of the Damned establishes that witches and spirits are real. Memnoch the Devil claims that God, the angels, and The Devil are all real.
    • However, despite Lestat having actually met Christ, Rice insists that her biographical novels recounting the life of Jesus are not part of the same continuity.
  • J. R. R. Tolkien:
    • The Hobbit was not, at the time of its writing, intended to be in the same continuity as The Silmarillion, which Tolkien regarded mainly as personal recreation and had as yet no intent of publishing. Despite this, he couldn't help throwing in a few names and locations that referenced The Silmarillion. When he began writing the sequel that would become The Lord of the Rings, he went whole-hog and moved The Hobbit to Middle-Earth, The Silmarillion becoming the Back Story of the novels. In fact, the ring that Bilbo found was originally just an ordinary, harmless magic ring and nothing more, and Gollum, having no motive to kill Bilbo, happily led him to safety at the conclusion of the riddle game. It wasn't until The Lord of the Rings was being written that Tolkien decided that it was the ring, and he revised the Bilbo-Gollum encounter in order to make it more sinister. The in-universe explanation for the altered narrative is that Bilbo wrote the first version while under the influence of the ring as he wanted to conceal the actual circumstances of his acquiring it. The revised, true version was written later, after he was no longer in the ring's grasp.
    • Tom Bombadil, Goldberry and Old Man Willow originally appeared in a poem published in 1933. They had no connection to Middle-Earth until the writing of The Lord of the Rings was in progress, and that didn't turn them into anything more significant than a Wacky Wayside Tribe.
  • Robert A. Heinlein did this towards the end of his career, incorporating all his previous stories (often with radically different universes) into one meta-universe, thanks to a handy trans-dimensional device invented by one of his characters. Then he brought the John Carter of Mars series in, and the Oz books, and eventually all fiction ever created.
    • Though he did give preference to the ones he liked, and especially those written by authors with whom he was personally acquainted; one of the transdimensional 'jumps' involved taking the characters into the Lensman universe created by his friend, E. E. “Doc” Smith. He even threw in some real people: the characters of The Number of the Beast run into Charles Dodgson while in Wonderland, and near the end of the novel, it's mentioned that Bob, Arthur, and Isaac should be showing up for a big meeting soon.
    • Nearly all main characters he ever wrote are in one scene at the end of The Cat Who Walks Through Walls.They try to recover Mycroft Holmes, whose death was perhaps the biggest Tear Jerker Heinline ever wrote. Towards the end the characters are aware they are in a story, and find the Author to be a bastard...
  • Larry Niven originally had two continuities: the first was the "slowboat" stories of early colonization of space by humanity (featuring the novels World of Ptavvs, the Gil Hamilton stories, and A Gift From Earth), while the second featured faster-than-light travel and aliens (featuring the stories of Beowulf Shaeffer, Louis Wu, and the Ringworld. And then he wrote his short story "A Relic of the Empire", which combined the two continuities and created the Known Space universe.
  • The first novel in Terry Pratchett's Nomes Trilogy, Truckers, takes place in the (real) town of Grimethorpe, but in the later books the Store is relocated to Blackbury, which is also the setting of the Johnny Maxwell Trilogy.
  • Edgar Rice Burroughs had Tarzan travel to the underground world of Pellucidar in order to rescue the hero of the series. ERB weaved together the continuity of his books in other ways.
    • The character Jason Gridley is introduced in Tanar of Pellucidar, meets Tarzan in Tarzan at the Earth's Core, and appears as part of the frame story in A Fighting Man of Mars and Pirates of Venus, linking together Burroughs' four main series.
    • The technology for the Moon mission from The Moon Maid was Barsoomian in origin.
    • Tarzan is a supporting character in The Eternal Lover, whose central character is the sister of the hero of The Mad King; thereby bringing those otherwise non-series novels into the fold.
  • Terry Brooks' Shannara series was always established as being set a fantasy world that formed After the End of modern civilisation. His The Genesis of Shannara series is set during the collapse of civilisation, and establishes the Four Lands as the future of his The Word and the Void novels.
  • What August Derleth called the "Cthulhu Mythos" (a term never used by H. P. Lovecraft and only by Derleth after Lovecraft's death) originated from cross-references by Lovecraft between his own stories and that by other writers. Lovecraft, not Derleth, referenced passages from the Necronomicon, other forbidden books, or placing offhand comments during the expository monologues, about various Eldritch Abominations having no bearing on the current story. Specifically, The Dream-Quest of Unknown Kadath ties most of his early standalone short stories into the Dreamlands Cycle, and also brings in "Pickman's Model" and the Randolph Carter stories. The Dreamlands Cycle is ultimately linked to the so-called Cthulhu Mythos, though a few stories, such as the early "Dagon", may be outside the grand continuity. Several other authors have tied them together, notably August Derleth and Clark Ashton Smith. Even the demonic race beneath the Earth from "The Rats in the Walls" appears to be referenced in "The Whisperer in Darkness".
    • Clark Ashton Smith's Xiccarph and Zothique series were not originally connected to the "mythos" in Smith's own writings.
    • Lovecraft and others tied works by earlier writers he did not personally know. For example, RW Chambers' The King in Yellow (referenced in "The Whisperer in Darkness"), to the work of Arthur Machen (the Aklo language) and Lord Dunsany (Bethmoora).
    • Though they never met in person, Lovecraft and Robert E. Howard were pen pals and some of their letters discuss plans to combine their respective universes, but their untimely deaths prevented this from being made a reality beyond a few vague hints in various stories.
  • Stephen King:
    • Beginning with It, King began tying many of his novels into The Dark Tower series, to the point that every single novel he wrote during the early 2000s was somehow related to the epic. The process included bringing back a character he Put on a Bus (literally) in Salem’s Lot and retconning the Big Bad from The Stand into the Crimson King's Dragon. (Indeed, the Crimson King himself made his first appearance outside The Dark Tower series.)

      From Desperation (1996) to From a Buick 8 and Everything's Eventual (2002), 100% of King's fiction output (six novels and two story collections) tied into The Dark Tower (at least retroactively). These were bookended by Wizard and Glass in 1997 and the conclusion of The Dark Tower series in 2003-04. There's also the aforementioned incorporation of everything back to Salem's Lot and The Stand, written before The Gunslinger.

      And lest we forget, Salem's Lot takes place in the same city as Jerusalem's Lot, an earlier short story, confirmed to be in the Cthulhu Mythos. Therefore, The Dark Tower series is part of the Mythos by extension. Oh and as mentioned above Transformers, Doctor Who, Sherlock Holmes, and everything else on this page has crossed over with the Cthulhu Mythos.
    • It's also been established that if there's anyone in a King story with the initials R.F., they're probably a very particular person: Randall Flagg, the Big Bad of The Stand, The Eyes of the Dragon (as Flagg, no first name), and the Crimson King's Dragon. Except for (presumably) Rudy Foggia of The Jaunt, who is quite dead at the beginning of the story.
    • It also contains an appearance by Charles Pickman, from the H. P. Lovecraft story Pickman's Model — which ties it to all the Lovecraft stories mentioned below. King's next novel, The Tommyknockers, not only crossed over with It, but also tied in several of King's other novels, including Firestarter and The Talisman.
    • Also, the books Dolores Claiborne and Gerald's Game refer to each other, as the female protagonists of the books have a psychic link, having times when they suddenly get the feeling that this other person, whom they don't know, is somehow in danger.
    • Misery refers to The Shining at one point, when Annie mentions the ruin of the Overlook Hotel.
  • Tony Hillerman once had two series, one featuring Navajo cop Jim Chee and one featuring Navajo cop Joe Leaphorn. There is now only the Leaphorn & Chee Mysteries.
    • Though to be fair, from the beginning the Chee stories (which came second) would reference Leaphorn and characters and events from his stories—they just weren't featured in the same books for a while.
  • Before he's done, F. Paul Wilson's Adversary Cycle bids fair to weave in practically every book and short story the man has ever written.
  • Mercedes Lackey's assorted Urban Fantasy stories seem to be set in different continuities, until mention is made of the west coast elfhames (from the Bedlam's Bard series) in the SERRAted Edge novels, and of Tannim, the mulleted protagonist of the SERRAted Edge novels appearing as a bit character in his teens in Jinx High, a Diana Tregarde investigation.
    • Since Jinx High was Tannim's first appearance, and the Bedlam's Bard events were namechecked in the first SERRAted Edge novel, this one was evidently intended from the start, or nearly so.
  • Kate Elliott has confirmed that her new Crossroads trilogy of fantasy novels is actually a fictional story within the context of her earlier Jaran series of SF novels.
  • Peter F. Hamilton retconned several of his earlier SF short stories to be set in the same universe as his immense, later The Night's Dawn Trilogy and published them in a collection called A Second Chance at Eden. However, he has avoided this phenomenon elsewhere and has created no less than three distinct SF universes existed at similar points in history, making it impossible for them to coexist in the same continuity.
  • Alastair Reynolds did something similar with several of his early SF short stories, retrofitting them into his Revelation Space series of books and publishing the results as a collection called Galactic North.
  • Guy Gavriel Kay's The Fionavar Tapestry presents the world of Fionavar as so significant that echoes of it appear in the mythologies of every other world in The Multiverse. His subsequent stand-alone novels Tigana and The Lions of Al-Rassan, although each set in a different world, each has a moment showing that to be true. Ysabel is more overt, actually featuring several characters from the Fionavar Tapestry later on.
  • The Peter David novel Howling Mad mentions Mayor Penn, who is the returned King Arthur from Knight Life.
  • A particularly confusing example is The Well of Lost Plots, which ties the world of Thursday Next into a book (now a series) that Jasper Fforde wrote first, but which was published afterwards (The Big Over Easy, originally Nursery Crimes), and does so by establishing it as fictional within the Nextiverse, although, like all works of fiction, Thursday can enter it, and spends most of the book inside it, being ultimately responsible for its odd mix of genres. Everyone follow that?
    • To further confuse things, the Thursday Next stories are themselves fictional within the Nursery Crimes series.
  • Agatha Christie's Author Avatar Ariadne Oliver seems to tie several of her series together. She originally appeared in the Parker Pyne stories (as did Miss Lemon). Then she became established as a Hercule Poirot character, starting with Cards On the Table (which also featured Superintendent Battle, who'd previously appeared in the two novels starring Bundle Brent). Then she was the main character in the 1961 novel The Pale Horse, which also featured the vicar's wife from the Miss Marple novel The Moving Finger. And in Murder in Three Acts, Poirot meets Mr Satterthwaite, who previously appeared in The Mysterious Mr Quin collection of short stories. Tommy and Tuppence are also linked, since the same slightly unhinged old lady appears in The Pale Horse, the Miss Marple novel The Sleeping Murder, and the Tommy and Tuppence novel By the Pricking of my Thumbs, despite Partners in Crime having them refer to Poirot as a fictional character. Then again, Partners in Crime mentions Poirot, but not Agatha Christie, and the novel that Tommy references is The Big Four, one of the ones narrated by Hastings, so maybe it was, in-universe, written by Hastings, Watson-style.
    • Tommy and Tuppence can also be linked to the others through a mysterious character who is only referred to as Mr. Robinson. This character appears with Poirot in Cat Among the Pigeons, Marple in At Bertram's Hotel, and Tommy and Tuppence in Postern of Fate. He also appears in Passenger to Frankfurt, which does not feature any of Christie's series detectives.
  • While Kim Newman has seeded connections between his books since the beginning, the short story "Cold Snap" seems to be a concentrated effort to tie them all together. A "Diogenes Club" story (and therefore featuring characters whose Alternate Universe selves appear in the Anno Dracula novels) it adds characters from his early work such as Jago, and even features the villain from his Doctor Who novella Time And Relative.
    • Under the pseudonym Jack Yeovil, Newman wrote a number of books based on Games Workshop properties. Krokodil Tears, one of the Dark Future books, had its Big Bad have a vision of an alternate version of himself as the Big Bad from his Vampire Genevieve series of Warhammer books.
  • Kim Newman isn't the only author to tie his personal Verse into the Whoniverse. Iris Wildthyme was a character in Paul Magrs' Magic Realism novels, before he revealed she was an extremely eccentric Time Lady.
    • Iris Wildthyme, in her appearances in novels and audios, occasionally interacts with an organisation called MIAOW, The Ministry for Incursions And Other Wonders (simultaneously a parody of Torchwood and Doctor Who's UNIT). This organisation has also turned up in his Brenda and Effie series of novels set around Whitby. Characters from his Eighth Doctor Adventures novel Mad Dogs and Englishmen, his Big Finish Doctor Who audio drama The Boy That Time Forgot, and the Pheonix Court series that featured the original version of Iris have also appeared in this series. A character from one of Magrs' Tenth Doctor novels also reappeared in an Iris Wildthyme short story, along with a character from the Brenda and Effie series.
  • H. Rider Haggard's novel She and Allan brought together Ayesha from She and Allan Quatermain from King Solomon's Mines.
  • E. E. “Doc” Smith's Lensman series of novels was originally 4 books long (initially published in serial form in an SF magazine). In the late 1940s or early 1950s, he took an early work of his named Triplanetary and retrofit it in with the rest of the Lensman universe. He wrote an additional novel, First Lensman, to bridge the gap between the two storylines.
  • Jules Verne did this quite a bit:
  • David Gemmell has stated that all his books take place in the same world, despite covering vastly different territory, such as a low-magic fairly standard fantasy world (Drenai saga), a post-apocalyptic world (The Jerusalem Man) and our own world (an Arthurian duology and a duology set in ancient Greece). (Those last three are explicitly connected by the plot device of the Sipstrassi stones.)
  • L. Frank Baum, the author of The Wonderful Wizard of Oz, also wrote Oz sequels and non-Oz works of fantasy. Through several Crossovers, he established that all of them take place in the same magical continent, called Nonestica.
  • Leslie Charteris introduced Inspector Teal in the novel Daredevil featuring Storm Arden before Teal appeared in the Saint series.
  • Poul Anderson's Nicholas van Rijn stories and Dominic Flandry stories weren't, originally, part of the same universe. But a bit of prodding by fans, and he wrote some bridging so that now they are both part of the Technic History.
  • Dale Brown has done this. Rebecca Furness and Daren Mace, characters originally in the non-Patrick McLanahan book Chains of Command, joined the main continuity in Battle Born and Warrior Class respectively. The eponymous space station of Silver Tower, thought a victim of Canon Discontinuity because of its long absence from his books, joins the main continuity in Strike Force. The Dragon of non-Patrick McLanahan book Storming Heaven, Gregory Townsend, is Dragon Ascendant Big Bad of main continuity title The Tin Man.
  • Iain Banks, in his mainstream (non-SF) literature has said he doesn't do sequels/prequels; though he did include one subtle crossover in Complicity: Cameron's friend Al, an engineer he met on a paintballing weekend, is Alexander Lennox, recovered from his car-crash in The Bridge.
  • All of Christopher Moore's varied books appear to take place in the same verse, whether the setting is modern suburban California or Israel in Jesus's time. Various characters make appearances outside of their respective novels, like angels and vampires and fruit bats. Of course, whether this is actual canon welding or just his Verse depends on whether Moore had the broad strokes sketched out from the start or just made it up as he went (and tied it together afterwards)!
  • Philip José Farmer took this to the extreme in his creation of the Wold Newton Universe. His novels Tarzan Alive and Doc Savage: His Apocalyptic Life link the two heroes' respective families to the same event, the meteor strike in Wold Newton, Yorkshire, England, on December 13, 1795. Other stories, both by Farmer and other writers, have expanded the Wold Newton universe to demonstrate links to The Scarlet Pimpernel, Sherlock Holmes, The Spider, James Bond, Nero Wolfe, Sam Spade, The Lone Ranger, The Green Hornet, and even Star Trek.
    • In a way, his series of books beginning with To Your Scattered Bodies Go could be considered the logical conclusion of this trope, as he intentionally designed a world in which he could bring in any character from any story written by anyone.
  • Madeleine L'Engle first connected her "Kairos" and "Chronos" series when Canon Tallis from Kairos novel The Arm of the Starfish appears in Cronos novel The Young Unicorns; several characters from each series would cross over later.
  • In The Art of Detection, Laurie R. King welds her wildly successful series about Sherlock Holmes' female apprentice to her lesser-known series about a modern San Francisco cop. The novel is a serious Mind Screw, as Sherlock Holmes appears to be simultaneously real and fictional in it.
  • Simon R. Green's series The Nightside, Secret Histories, and Ghostfinders take place in the same world. And constantly reference each other. There are also very strong connections to his Deathstalker, Forest Kingdom, and Hawk and Fisher series. And all his other writings.
    • In the latest Nightside novel there's even a perspective-flipped recreation of a scene from a Hawk and Fisher novel, of the duo waiting at a tavern to meet Razor Eddie.
  • An unreleased series of novels (Alien Exodus and The Human Exodus) in the Star Wars Expanded Universe would have done this between Star Wars, THX 1138, and American Graffiti. The novel would have had descendants of the characters from the latter two works warp across time and space to A Long Time Ago, in a Galaxy Far Far Away... and become the first humans in that place.
  • Narita Ryohgo wrote links establishing that his three series of light novels - Baccano!, Durarara!! and Vamp! - all take place in one universe. For example, Shizuo from Durarara mentions getting into a fight with person strongly implied to be one of the Baccano! characters.
  • It's not clear if this was intended from the start, but a minor character in the Starbuck series (set in the American Civil War) by Bernard Cornwall was revealed in the second book to be the son of Richard Sharpe, the hero of the Sharpe series, Cornwall's earlier and more famous series set in the Napoleonic Wars.
  • Neil Munro wrote two series of short stories for the Glasgow Evening News: Erchie, My Droll Friend about a Glaswegian waiter, and Para Handy, Master Mariner about a steamboat going up the West Coast of Scotland. When Erchie needs to take a ship to his daughter's wedding, naturally it's Para Handy's Vital Spark.
  • Andrzej Pilipiuk has connected his Jakub Wędrowycz stories with his more serious trilogy called Kuzynki (Cousins) - Jakub is mentioned by name in second volume and makes a cameo in third, combined with the illustration to leave no doubt that this is indeed him. This is odd, because in first book of the trilogy Jakub is clearly fictional as one of the characters reads his books and considers them the evidence that modern Polish literature is terrible.
  • E. F. Benson's Mapp And Lucia series only came together with the novel of that title, which brought the characters of Miss Mapp together with those of two previous Lucia novels. Although not regarded part of the series per se, another earlier novel Secret lives was also subsequently tied into the same continuity.
  • Anne McCaffrey:
  • Just about every book by Douglas Preston and Lincoln Child take place in the same fictional universe. They're probably best known for the Agent Pendergast series, but even their non-Pendergast books share characters that tie in with one another. For example, one of their earlier books, Thunderhead, introduced anthropologist Nora Kelly and featured William Smithback from their first Pendergast-related novels; Kelly was later made a recurring character in the Pendergast novels. Two Pendergast novels feature a wheelchair-bound profiler named Eli Glinn, he was introduced in an earlier novel entitled The Ice Limit and has later appeared in their new Gideon Crews series of novels. Mime, a hacker from the duo's second book Mount Dragon, has appeared in their later Pendergast novels.
  • Several of Piers Anthony's works. The last book of the Mode series featured a brief trip to Xanth. The 27th Xanth book included a visit to Phaze, a world from the Apprentice Adept series.
  • At the end of Christopher Anvil's "War With The Outs" series, humanity learns that beyond the Outs' territory, space is controlled by two new alien races, the Stath and the Ursoids. Both of these had previously made appearances in his "Colonization" series, suggesting that the "War With The Outs" stories take place earlier in the same universe.
  • Susanna Clarke published a short story where one of characters from Jonathan Strange & Mr Norrell visits village from Neil Gaiman's Stardust, making both stories take place in one world. As far as we know, this is still canonical.
  • Older Than Radio: French writer Honoré de Balzac wrote a few independant novels and short stories before making recurring characters. He next made the project of making a study of human society and called his work The Human Comedy (in reference to The Divine Comedy).
  • Older Than Print:
    • As the original versions of the stories have been lost and had to be speculatively reconstructed by scholars from the evidence of the various German and Scandinavian versions it is hard to tell, but it is quite clear that the Nibelungenlied is an amalgam of some quite different stories, and it is a matter of conjecture to decide when the welding of the elements occurred and which ones are to be attributed to the author of the Nibelungenlied. The story of the dragonslayer called Siegfried or Sigurd accounts for the first half of the main plot and the originally unrelated story of the death of the Burgundian kings at the hands of the Huns and their king Atli (Attila) for the second. The welding necessitated some changes, thus in the Scandinavian epics that contain just the Atli saga, the sister of Gunther, who is married to Atli, kills her husband to avenge her brothers. In the Nibelungenlied Kriemhild kills her brother using the army of her second husband Etzel (Attila) to avenge the murder of her first husband Siegfried.
    • A canon-welding that does seem to be the idea of the writer of the Nibelungenlied is the inclusion of Dietrich and his knights in the finale, which fuses the Nibelungen story to the cycle of epics about Dietrich of Bern (Theoderic the Great). In that cycle Attila was presented essentially as a sympathetic character and generous host, not the kind of treacherous and cold-blooded killer as in the Atli sagas.
  • George Mann's timeline of the Newbury & Hobbes universe, at the back of The Casebook of Newbury & Hobbes, includes his Sherlock Holmes novel, his Doctor Who – Expanded Universe work and The Ghost (2010).
  • Robert E. Howard did this a lot with his historical, horror and fantasy stories. Just to name a few examples: Kull was explicitly tied with Conan the Barbarian in the essay "The Hyborian Age". Both was tied with the historical-fantasy character Bran Mak Morn through the Kull-Bran crossover "Kings of the Night". The ring of Thoth-Amon, from the Conan stories, and worshipers of Bran are featured in Howard's modern horror stories, while both Bran and Kull are mentioned in one of his Turlogh Dubh O'Brien stories set in 1200's. It wouldn't be unreasonable to consider all of Howard's speculative fiction to be part of the same verse, even if Howard never lived to point it out himself. And of course Howard and H. P. Lovecraft making references to each-others in their works was the foundation of the Cthulhu Mythos mention above.
  • Members of a family named "Hempstock" have appeared in quite a few seemingly unconnected works by Neil Gaiman, including Stardust, The Graveyard Book and, most predominately, The Ocean at the End of the Lane. Death from The Sandman also gets a mention in Stardust.
  • Indie author Royce Day's Space Opera The Red Vixen Adventures series and Diesel Punk novella Prisoner of War both involve characters of a species that resemble humanoid foxes, feature characters who express similar religious and political views, and have a protagonist named Lord Rolas Darktail. But it wasn't confirmed as the same 'verse until Shadow of her Sins in the former series, which featured a minor character from Gerwart, an expy of Germany from "POW".
  • There's a Flashman book where the title character (himself originally from Tom Brown's Schooldays) encounters Sherlock Holmes, Watson, and their nemesis Tiger Moran.
  • Steve Alten 's flagship Meg series and his seventh novel, The Loch, became part of the same continuity with the latter book's sequel Vostok.
  • An unusual example of an author allowing someone else to Canon Weld their work: the Arthur C. Clarke's Venus Prime series by Paul Preuss have as their premise that many of Clarke's stories are set in a single Verse.
  • Roland Smith linked his Jacob Lansa series with the standalone book Sasquatch by having Buckley Johnson, a character from the latter, appear in the third Jacob Lansa book. Lansa later appeared in Tentacles, the second of the Cryptid Hunters series, and returned in the sequels alongside Dylan Hickock, the protagonist of Sasquatch.
  • The Marla Mason series' ninth book, Lady of Misrule, reveals the author's previously stand-alone novel The Strange Adventures of Rangergirl to be set in the same universe.
  • This, alongside Executive Meddling, is the very origin of the Sandokan series: the author Emilio Salgari had originally written The Tigers of Mompracem as a stand-alone novel (and made clear in the ending that Sandokan was retiring from piracy) and planned a Tremal Naik series starting with The Mistery of the Black Jungle (that ended with a Cliffhanger), but when reprints of the former outsold the latter by a fair margin the publisher asked Salgari to bring back Sandokan, and The Pirates of Malaysia starts with Kammamuri from The Mistery of the Black Jungle learning that Sandokan has unretired... And the ship he's on has wrecked on his island.
  • The Kate Shugak novel Restless in the Grave features an appearance from Liam Campbell, the Alaska State Trooper protagonist of Dana Stabenow's other crime series, and other characters from his books. It may be a Fully Absorbed Finale as there have been no Campbell novels since, and in Restless in the Grave Liam has finally married his long-term love interest, and his mentor Moses is killed off at the climax.
  • "The Dancing Floor", one of Cherry Wilder's last published works, combines elements from her Torin novels and her Rhomary Land novels, establishing them as part of the same future history.
  • Keith Roberts' short story "Unlikely Meeting", published in Interzone #88, has teenage witch Anita meet Kaeti from Kaeti and Company. Since Kaeti and company are a Universal-Adaptor Cast anyway, he doesn't need to worry much about how it all fits together. (They've both read each others' books but it's not even particularly clear whether that's Mutually Fictional or A True Story In My World.)
  • Matthew Reilly novels often drop references to his other works. It kicked up a notch when a character from a Scarecrow novella appeared in the Jack West Jr books, and up a few more notches when Scarecrow himself (protagonist of the eponymous series) shows up as a main character in the fourth Jack West Jr. novel, while references were made to other Scarecrow novels.
  • The Giver Quartet: initially a standalone, The Giver is about a boy named Jonas who lives in a False Utopia; he escapes at the end, along with baby Gabe, but their fate is ambiguous. Another Lois Lowry book, Gathering Blue, is set in a primitive village After the End, but the characters eventually find a more advanced village with characters who might be Jonas and Gabe; Word of God initially said that it was up to reader interpretation. The following sequels, Messenger and Son, slowly do away with any ambiguity.
  • Clive Barker did this with The Scarlet Gospels distinctly bringing Harry D'Amour and The Hellbound Heart and Hellraiser character Pinhead together, but there were hints in earlier books this may have been planned for longer.
  • The Five Kingdoms series is set in the same Multiverse as that of the author's previous work, The Beyonders. Two characters who died in the previous series show up in the world's shared afterlife in Five Kingdoms, and it's mentioned by those characters that the creatures known as torivors who trouble the Outskirts are a problem in their world, too.
  • Donald Kingsbury's Psychohistorical Crisis: A Fan Sequel to the Foundation series retcons several setting details and ties in Dr Asimov's otherwise unrelated Novelette "Nightfall (1941)". Since it's not "official", it's free to ignore the Robots connection, and does so.

    Live-Action TV 

    Mythology and Religion 
  • Robin Hood went through several rounds of this, along with Adaptation Displacement. Maid Marion (or "Marian"), Friar Tuck, and Alan-a-Dale were all characters from separate folk tales, and it was only later that Robin Hood stories had anything to do with Richard the Lionheart or Prince John.
  • The Equivicatio Romana by which each of the gods and goddesses of the other pantheons the Romans encountered was said to be another name for the nearest equivalent in their pantheon—sometimes by a great deal of squinting.
  • Euhemerism which postulates that the pagan gods and goddesses were actually great heroes and heroines who lived long ago and whose reputations snowballed until they became gods.
    • Herodotus one-ups Euhemeris by trying to equate Egyptian mythology and Greek mythology.
  • The two Classical Mythology stories that bring together large numbers of Greek heroes likely have their origins in Canon Welding: the Voyage of the Argo and the Calydonian Boar Hunt both feature characters like Herakles, Theseus, Bellerophon and so on.


  • The Green Hornet was the son of The Lone Ranger's nephew back when the two were on the radio. However due to legal issues between those who currently own the two franchises, the connection isn't used at all anymore.
  • When The Last Chance Detectives were adapted to radio, their premiere episode included an appearance by Jason Whittaker of Adventures in Odyssey, welding the two previously unrelated Focus on the Family franchises.

    Tabletop Games 
  • An odd version of this exists in Dungeons & Dragons. Gods cross over from one campaign setting to another, spells exist under different names, and so on. Initially the settings were welded only by implication, mostly mythological crossovers (shared gods) and in the names of spells ("Bigby's Grasping hand", "Mordenkainen's Hound") indicating that divine beings and powerful wizards COULD travel between them, but providing no actual explanation. Later, the Planescape and Spelljammer meta-settings provided two (amusingly contradictory) explanations: in Planescape a stock-fantasy multiverse exists, with the added benefit of explaining where all the more biologically impossible elemental and evolutionarily improbable critters come from. Spelljammer is based on medieval cosmology, and adventurers can sail between the various crystal spheres in mighty magical craft riding currents in the luminiferous aether.
    • There was also the World Serpent Inn, which even links campaign settings which are explicitly not part of the Planescape/Spelljammer cosmology, such as Eberron.
    • Ravenloft is, itself, a product of Canon Welding, as its Patchwork Map incorporates several domains that were inspired, copied, and/or outright stolen from other AD&D campaign worlds. Literally stolen, in some cases.
    • The "legendary" settings of the various AD&D Historical Reference books were eventually revealed in the Chronomancer appendix to be the past of Gothic Earth from Ravenloft's Masque of the Red Death ...which in turn may be the past of one of the magical d20 Modern settings — probably Shadow Chasers (the Red Death gets mentioned in the Menace Manual).
    • In D&D 4th Edition, there was a policy to enforce uniformity across the gameline by inserting setting elements from the core material into all official D&D settings, and retcons and setting-shaping disasters were applied wherever necessary to make it so. For example, the cosmology of the Forgotten Realms had to allow for such things as the Primordials and the Feywild because those were part of the Nentir Vale cosmology. However Dark Sun in 4e was largely able to maintain its independence from such core elements, either by slapping new names on old Athasian material (and often ignoring them afterwards) or by rejecting them entirely if they couldn't. (This is in part helped by Dark Sun's traditional independence from the rest of the D&D line; crossovers were firmly discouraged even at the height of the TSR and Planescape days.)
    • The D&D 5th edition supplements Plane Shift: Innistrad and Plane Shift: Zendikar enable campaigns to be set in the Magic: The Gathering multiverse.
  • The Old World of Darkness started off as a set of tabletop RPGs each designed as a stand-alone, but since they shared the same basic gameplay and theme, crossovers were an obvious possibility. White Wolf acknowledged this by grouping them together, but they don't all fit that well. Vampire: The Masquerade has a Biblical origin story, while Werewolf: The Apocalypse has a pagan backstory. Vampires and mages are both supposed to have secret societies manipulating human history for centuries at least, with directly conflicting goals, yet there's only one case in canon of them fighting each other. And several games have a metaplot pointing to the forthcoming end of the world, but all have a different scenario for it. When it came to mechanics, mages can curbstomp any of the other supernatural beings unless caught unaware (especially vampires, since the best way to counter mages' magic is to be alive).
    • The New World of Darkness is made with the possibility of such crossovers explicitly in mind, at the same time keeping each group generally out of each others' way. For example, the Supernal Realms of Mage: The Awakening and the Shadow World of Werewolf: The Forsaken have little to do with each other, but equally don't step on each other's cosmological toes.
    • Exalted was an inversion. The original concept for the game was for it to be set in the forgotten, mythical prehistory of the Old World of Darkness... but it was ultimately decided not to make this an absolute of the setting, and reduce the connections to common setting elements and parallels that hint at the possibility. The tagline "Before there was a world of darkness..." is The Artifact of the original concept.
  • Rifts.
    • Want Robotech mecha to fight the Teenage Mutant Ninja Turtles alongside unicorn-riding cyborgs, only to have them all ambushed by eldritch abominations? Have at it! Palladium Books specifically published conversion books for incorporating their other franchises into Rifts rules.
    • The Rifts Chaos Earth RPG (which takes place during The Great Cataclysm) explicitly state that Rifts is the future of the Beyond The Supernatural setting. This had previously been Kevin Siembieda's headcanon, but he hadn't wanted to firmly state it because Rifts was also supposed to be our Earth's future.
  • The Warhammer and Warhammer 40,000 universes used to be linked, although the linking statements were made by mad characters. The whole saga/background is told through an Unreliable Narrator anyway. Games Workshop has stated that the link is now done away with, since it was mostly silly anyway. Warhammer world used to be a planet in the 40k universe, surrounded by warp storms that made it inaccessible for the rest of the galaxy. Nowdays they exist in separate universes, but there appears to be a small link between them in the form of the Warp (the Chaos Gods are the same in each universe, and some people in Warhammer world have gotten visions of Chaos in 40 universe. For example, in Liber Chaotica: Book of Khorne, it's all but outright stated the author is having visions of Abaddon's 13th Black Crusade. Also the Old Ones in Warhammer appear to be the same as the ones in 40k, and a fan theory suggests they escaped from 40k universe to Warhammer one after the War in Heaven). There is no real interaction between the two universes, however, unless you count some daemon characters popping up in both universes and a few magic items that have a suspicious resemblance to 40k technology. It also used to be fairly heavily implied that Sigmar (the fantasy Empire's messiah figure and founder) was one of the missing Primarchs (genetically enhanced superhuman offspring of 40k's Emperor). Warhammer 40,000 was later considered to be simply the Spiritual Successor where everything is an expy of the original Warhammer Fantasy.
  • The GURPS Infinite Worlds setting ties together every alternate universe they ever came up with and every licensed work ever adapted to GURPS from Uplift to Discworld to Hellboy.
  • Earthdawn is canonically set in the distant past of the Shadowrun setting.

    Theme Parks 

  • Transformers:
    • Pepsi Convoy is made of sentient metal, the substance that makes up Pepsiman.
    • The "Alternity" toy line links the alternate universes of Binaltech, Binaltech Asterisk, and the Kiss Players radio drama, based on the Japanese Transformers Generation 1, and Micron Densetsu, the Japanese version of Transformers Armada, and the Action Figure File Cards of the Transformers live-action film toy line, and the game Transformers: Convoy no Nazo.
    • G.I. Joe is referenced with the Transformers: Energon Snow Cat (Cyclonus) transforming into a Snow Cat vehicle, the Transformers Timelines subscription exclusive "Serpent O.R." referencing Serpentor, and the Transformers: Generations Combiner Wars Viper turning into a Cobra Rattler plane with a combined Cobra/Decepticon insignia. Exclusive sets from San Diego Comic-Con and the Transformers Collectors' Club combine both series.
  • Through commercials, The Trash Pack, Shopkins, and The Grossery Gang, all blind-bagged rubber figurines by Moose Toys, share a world.

    Video Games 
  • BioShock Infinite combined all of the previous BioShock games, and perhaps even the System Shock titles, into the umbrella of the multiverse. Logistically, this is Ken Levin's way of hand-waving his recurring power-ups and obstacles.
    Elizabeth: (delighted) A Sky-Hook!
    Booker: A "Sky-Hook"? You mean the Air-Grabber? Kids use 'em to ride up around the pneumo lines.
    Elizabeth: Air-Grabber, huh. "Constants and variables"...
    Booker: Constants and what?
    Elizabeth: Nevermind.
  • In Dragon Quest Monsters, Caravan Hearts ties to Dragon Quest II and the original trilogy. Terry's Wonderland ties into Dragon Quest VI.
  • Street Fighter:
    • Street Fighter Alpha effectively combined the Street Fighter and Final Fight franchises into one shared continuity, by featuring Guy and Sodom from the first Final Fight as playable characters, followed by Rolento in Alpha 2 and Cody in Alpha 3. Final Fight was originally intended to be a sequel to the first Street Fighter, and, most importantly, the two franchises had been already officially part of the same continuity since the console version of Street Fighter II first came out (proof of this was in the instruction booklet). By extension, this also puts Street Fighter in the same universe as Saturday Night Slam Masters, since both that series and Final Fight feature the character of Mike Haggar. This is confirmed in Street Fighter III, where Hugo's ending has him about to enter into a tag-team match against two Slam Masters characters, who will vary depending on who his partner is (for instance, if Elena is chosen, she and Hugo will face off against Haggar and Black Widow). Ancillary material released for Street Fighter V also mentions that Rainbow Mika's coach, Yoko, was forced to retire from wrestling after Black Widow injured her during a match. And if that wasn't enough, Captain Commando exists 20 Minutes into the Future of this Shared Universe, as one of the playable characters, Sho (Ginzu), is the successor of the Bushinryu ninjutsu utilized by Guy, a connection that is reiterated when they team up in Namco × Capcom. The very first level happens to be a future (but still crime-ridden) Metro City, and players can find a bust of Haggar that awards 5000 points at certain points throughout the game.
    • A localized example of this comes in the form of the aforementioned Hugo, who was added to the cast of Street Fighter III: 2nd Impact. His appearance is unmistakably that of Andore from Final Fight, who previously made a cameo appearance in Guy's Street Fighter Alpha 2 stage, and he even has Poison acting as his manager. For some odd reason, Capcom did not make any mention of the Andore family in Hugo's bio, instead stating his parents were farmers from Germany and bringing up how Hugo had two younger sisters. It wouldn't be until several years later that Capcom would acknowledge Hugo and Andore as one in the same, effectively fusing together his two backstories. A Mirror Match in Street Fighter X Tekken will result in the victor mistaking the loser for Andore Jr. while his intro sequence in Ultra Street Fighter IV features Hugo reminiscing about his mother and his life back home in Germany.
    • With Zeku's playable appearance in Season 2 of Street Fighter V comes heavy implications that he goes on to found the Striders, thus making the Strider series also part of the SF canon.
    • In the Capcom World games, and the mobile game Minna to Capcom All Stars/Street Fighter x All Capcom, Capcom World is the place where all Capcom heroes reside. Capcom World features Pure the Mage, who appears with several Capcom characters in Ken's stage in Street Fighter Alpha 2.
  • Mega Man Legends was originally in its own continuity (hence jokes and references to the original series being a Show Within a Show). However, Mega Man Zero and Mega Man ZX games have more directly connected it as being the far distant future of the original Mega Man and Mega Man X.
  • When SNK made Art of Fighting 2, they decided to officially make the Art of Fighting series part of the same continuity as the Fatal Fury series. To explain why the Art of Fighting cast were not around during the events of the Fatal Fury games, they made the Art of Fighting series a prequel to the Fatal Fury series by setting it ten years before and putting a young Geese Howard as the True Final Boss in Art of Fighting 2 (back when he was still the police commissioner of South Town). When SNK later wanted to cross the Fatal Fury cast with the Art of Fighting cast in The King of Fighters games, they had to place the third series in a separate continuity. And from there, it starts getting really weird, with Ralf and Clark from Ikari Warriors and Athena from Psycho Soldier (who is the descendant/ambiguously-the-reincarnation of the Athena from Athena) appearing in The King of Fighters — despite Psycho Soldier involving an invasion of monsters from beneath the earth that you'd kind of think would get mentioned at some point in KOF canonicity if it happened — and then both Ralf and Clark and KOF original Leona appearing in Metal Slug 6 and Metal Slug 7. At this point, the only sane response to the SNK canon is to throw up your hands and shout "I don't know!" Other SNK titles, from Samurai Shodown to The Last Blade to Savage Reign/Kizuna Encounter, have been alluded to in varying extents throughout KOF's run.
    • The King of Fighters XIV goes a step further by introducing the Another World Team, consisting of Nakoruru (of Samurai Shodown fame, last seen as a non-canon fighter in the Game Boy port of '95), Mui Mui (from the pachinko game Dragon Gal), and Love Heart (from the pachinko game Sky Love), who are drawn into the KOF world due to a dimensional rift. In short, the implication is that any of the SNK games that don't fit neatly into the KOF timeline, and even some of the ones that could, all exist as part of a greater cosmology.
  • The Final Fantasy series is mostly a Non-Linear Sequel, but has a few counts of direct crossover. Some early examples are Gilgamesh, who was banished to a world between universes and is the same person in most of his appearances. Cloud later appeared as a guest character in Final Fantasy Tactics, via a machine that can reach across time and space. (The remastered version of Tactics for the PSP also adds Balthier and Luso.) Around the time Dissidia Final Fantasy appeared, games (especially mobile spinoffs) began suggesting that all the worlds of Final Fantasy are planets in numerous universes separated by the Void, which can be crossed on occasion.
  • When Bohemia Interactive, the Czech developer of Operation Flashpoint: Cold War Crisis (their first game), split with the publisher Codemasters, they were able to keep the "assets"note  but not the game's brand name, so they ended up creating a Spiritual Successor called ARMA. However, BI has since come out and said that both series are in a Shared Universe, as was BI's spin-off Take On Helicopters, and indeed the British player character of both ARMA 2: Operation Arrowhead is a minor antagonist NPC in Take On Helicopters. The final patch (v1.99) for Operation Flashpoint even renames it to ARMA: Cold War Assault. Talk about paying attention to details.
  • Super Smash Bros.
    • The fourth game seems to pick up where both The Subspace Emissary (Brawl's Story Mode) and Kid Icarus: Uprising left off, as the various Palutena's Guidance conversations make reference to both games. Dark Pit's conversation in particular shows that, following the events of Uprising, he's decided to side with Viridi for reasons unknown.
    • The Smashverse versions of Marth, Ike, Lucina and Robin are summonable in Fire Emblem Fates, fittingly, via their amiibo (their real-life trophies). When talked to, they reflect on their experiences in the Smash universe, but Robin and Lucina also recognize characters from their game of origin that never appeared in Smash, which leads to confusion between the characters due to the whole Alternate Universe thing.
  • The Ultor Corporation, from Red Faction, a science-fiction series about Martian rebels, makes an appearance in Saints Row, a series about gang warfare in a contemporary American city. Red Faction: Guerilla references this with "Mount Vogel", named after the CEO of Ultor in Saints Row 2. This started off as a Shout-Out in the original Saints Row, with a few references to Ultor here and there. Then Saints Row 2 ran with it, and made Ultor a major faction that is clearly the same one as in Red Faction. However, Saints Row IV separates the canon, to say the least. Maybe. The ending implies a certain amount of time-travel, so who can say?
  • The sheer amount of Shout-Outs to NiGHTS in the Sonic the Hedgehog series has led some people (including those of semi-official status) to claim they are in the same universe.
  • Elemental - War of Magic shares a lot of its terminology (especially in its backstory) with Galactic Civilizations, indicating that the game may be set on ancient Altaria and the channellers are Sufficiently Advanced Aliens.
  • Betrayal at Krondor and Riftwar, mentioned under Cross-Media.
  • Easter eggs in Sierra's adventure games point to a shared continuity:
    • In Leisure Suit Larry, Rosella appears as a hairdresser in the second game and an actress re-enacting her game in the third game.
    • In Police Quest, it is possible to stop at the disco from Leisure Suit Larry, find a character from Leisure Suit Larry in jail, find Larry at the airport, and read news in the Lytton Tribune about dragons and gnomes in Daventry.
    • In Quest for Glory, The Adventurer's Guild Hall has a mounted Antwerp head: "The plaque reads: 'Antwerp – slain by Two Guys from Andromeda.'" In the SCI version, Erasmus' house has an artifact called "The Rosella Stone."
    • In Quest for Glory IV, the mad scientist Dr. Cranium is the great-great grandson of Dr. Thaddeus Egghead Brain from The Castle of Dr. Brain and The Island of Dr. Brain.
    • In Space Quest (EGA), pushing the Arcada escape pod's "Don't Touch" button sends the escape pod to The Daventry Zone, landing in Daventry Castle's moat, where Ken and Roberta Williams are having a conversation, mentioned by King Graham, Princess Rosella and Roger Wilco in Hoyle Book of Card Games, Volume I. In the VGA remake, the escape pod lands in Conquests of the Longbow's Nottingham Castle. In the VGA version, the Federation president strongly resembles King Graham.
    • In Space Quest IV, the helpless stranger, identified as Maharg in the game's files, is carried away by a Pterodactyl, much like the Roc carries away King Graham in King's Quest V. In the Galaxy Galleria, plants come from Shapeir florists.
    • In the Space Quest V copy protection, the Galactic Inquirer article "Gir Draxon's predictions for 3010" features Gir Draxon. Gir Draxon is the Supreme Overlord of the Arcturus system and Big Bad of Dynamix's Stellar 7, Nova 9 and Stellar-Fire series of futuristic tank games, though Gir Draxon is not in Stellar 7's spiritual sequel Arctic Fox. The StarCon Academy orbits planet Nova 9. In Nova 9, Nova 9 is the name of a star system.
    • In Space Quest VI, prisoners are sent to labor camps on the planet Daventry VIII.
    • The Hoyle games featured King Graham, Rosella, Roger Wilco, Sonny Bonds, Larry Laffer, and Sierra staff and relatives.
    • The extra-canonical hintbooks The King's Quest Companion, Leisure Suit Larry's Bedside Companion and The Space Quest Companion give the characters a Direct Line to the Author.
  • In 2011, Bandai Namco Entertainment merged parts of the previously unrelated (despite numerous Shout-Outs) Galaxian/Galaga series, Ace Combat series, Ridge Racer series, and some other games note  into an overarching United Galaxy Space Force (UGSF) series. Ace Combat 3: Electrosphere serves as its starting point.
  • In the PC game series Dark Parables, all fairy tales are true, and they're all part of one gigantic story. Sleeping Beauty is sister-in-law to The Frog Prince while Gerda is descended from Hansel, for starters. Sometimes characters from two (or more) different fairy tales will even turn out to be the same person; for example, Snow White is also the Snow Queen.
  • Commander Keen and Wolfenstein 3D are linked together by way of Commander Keen's Billy Blaze being the grandson of Wolfenstein's B.J. Blazkowicz. A common fan theory is that the protagonist of Doom is also part of the family. The RPG versions of their respective games go with this — the "Harbinger of Doom" from Wolfenstein RPG is basically Doom's Cyberdemon without prosthetics, and the hero of Doom RPG is explicitly given the last name "Blazkowicz." Also, Doom II's Commander Keen and Wolfenstein 3D's Easter Egg Bonus Level, though no in-story reason is given for their existence.
  • Ever since 2004, Ninja Gaiden has been established to be in canonicity with Dead or Alive series with Ryu being the canonical winner of the second tournament and Dead or Alive character Ayane acting as a support character throughout many Ninja Gaiden installments. Kasumi herself would later appear in the newer Ninja Gaiden games, first making two cameo appearances in Ninja Gaiden Sigma 2 before being bumped up to playable status in Ninja Gaiden 3: Razor's Edge. In turn, Rachel and Momiji (respectively from the 2004 Ninja Gaiden and Ninja Gaiden: Dragon Sword) would cross over to DOA with Dead or Alive 5 Ultimate. Additionally, Dead or Alive: Dimensions reveals that Sonia, one of Ryu's allies in Ninja Gaiden II, is merely an alias for Irene Lew, his love interest in the original NES trilogy (and wife by the time of the first DOA); Irene shows up in person during Razor's Edge and serves as Ayane's Mission Control after only being indirectly mentioned by Ryu in the original game.
  • Up until Fire Emblem Awakening, it was assumed that, barring remakes and direct sequels/prequels (and Gaiden which was a Gaiden Game to Shadow Dragon featuring a small number of its characters), all Fire Emblem games were set in different universes and did not impact each other. note  However, SpotPass and DLC content for Awakening used characters from previous Fire Emblem games—including ones that were not set in the Archanea universe—and so to get around this, introduced a "gateway" (the Outrealm Gate) that allowed characters to travel between the different universes. This would imply that all of the worlds are connected, physically or otherwise, as part of some greater universe rather than separate, alternate worlds. As detailed above, Fire Emblem Fates even adds the Super Smash Bros. universe to the mix.
    • Outside of a multidimensional context, the universe of Archanea, Valentia, and Jugdral was merged with that of Tellius.
    • A localized example comes from Echoes: Shadows of Valentia, the 2017 remake of Gaiden. While Gaiden was indeed a side-story to the titles set in Archanea, there were very few tangible links between games beyond the appearances of the Whitewing sisters and Zeke, an amnesiac Camus from Shadow Dragon, with one of these — Alm inexplicably finding the Falchion in Duma Temple — leaving players scratching their heads in confusion for many years. The remake, on the other hand, more neatly ties together Gaiden with the Archanean games as part of its expanded retelling. Aside of definitively stating Camus decides to stay in Valentia with his lover Tatiana following his stint as Sirius provided both of them survive to the end, SoV establishes Mila and Duma as members of the Divine Dragon Tribe who were exiled thousands of years beforehand, with Naga forging a second Falchion from one of her fangs and giving it to Duma as a countermeasure should they succumb to degeneration, much like many of the other dragons would in the backstory of Marth's games. In fact, Mila describes the Valentian Falchion as the "one and only godslaying sword," implying it was crafted far earlier than its Archanean counterpart. Furthermore, the postgame involves traveling across the sea to the western outskirts of Archanea, where the player investigates the ruins of Thabes, an ancient civilization in the Mamorthod Desert mentioned in Mystery of the Emblem. This dungeon, Thabes Labyrinth, manages to provide some much-needed backstory for none other than Grima, the Big Bad of Awakening, revealing he and the Death Masks, the original Risen, were the products of forbidden experiments conducted by a mad alchemist named Forneus, forcing the Thabean council to seal him and his creations away within his workshop.
  • Fitting its business model of only developing games that can be turned into franchises, Ubisoft seems well into doing this by starting to connect its existing franchises of Assassin's Creed, Watch_Dogs and Far Cry.
  • Lands of Lore and The Legend of Kyrandia share a continuity. Both mention the Kyragem, Piscata Rosea, Pseudobushia Hugiflora, and Scotia.
  • Discussed in Project X Zone where (on top of canonizing about a dozen other crossover games; see the Cross-Media section above) the characters from the many different universes have some fun trying to link them together. For instance, the characters of Gods Eater Burst find it plausible that their world would continue on a downward spiral, necessitating the construction of Basel in their far future. However, it's also acknowledged that certain universes are mutually exclusive with each other (Sakura Wars is technologically and geopolitically incompatible with modern Earth) or completely isolated (Tales of Vesperia is shown to be in its own disconnected bubble), so nothing is set in stone.
  • Quake III: Arena mashes Doom, Quake, and Quake II into a single continuity. Quake Champions mashes all of this with Id's remaining franchise, Wolfenstein, and possibly with Heretic and its sequels, if Galena is any indication.
  • Season of the Sakura and Runaway City both feature Rin Watanabe and the Virtual Ninja arcade game series, and share similar backgrounds and character designs, along with Three Sisters' Story.
  • The PS2-era Grand Theft Auto games are in the same continuity as the Manhunt series — Carcer City is explicitly stated to be a location in the Grand Theft Autoverse, and it was introduced even before Manhunt was released. And the Grand Theft Auto IV universe (which it shares with Grand Theft Auto V) may be shared with Bully, with the appearance of the Bullworth Academy on TV.
  • Some of Capcom's more robust crossovers, like Tatsunoko vs. Capcom and Marvel vs. Capcom 3, imply that many a Capcom franchise share some implicit but mostly unexplored degree of connectivity (going beyond the Shared Universe the Street Fighter franchise is known to be part of). For example, Morrigan in TvC expresses disappointment that Viewtiful Joe didn't live up to what she learned from Joe's rival Alastor. Alastor, as per the PS2 version of Viewtiful Joe, is the spirit of the sword Dante picks up in the original Devil May Cry and Dante's (admittedly non-canonical) story in Viewtiful Joe has Mundus, the Big Bad of the first DMC1, as The Man Behind the Man. Then, Dante and Joe are shown to be buddies/friendly rivals given their MvC3 intro quotes for each other, which would be strange (seeing as they never actually met in Viewtiful Joe) if not for the fact that Dante was a playable character in the PSP port of Viewtiful Joe: Red Hot Rumble.
    • If that wasn't enough, there are multiple hints throughout Bayonetta pointing to the fact that it exists in the same world as Devil May Cry, including the description for the Bracelet of Time note  name-dropping Dante's mother Eva while establishing her as an Umbra Witch who "entered into a contract with the legendary dark knight." Given that DMC and Bayonetta were created by the same guy (who was also responsible for the first Viewtiful Joe), this is not entirely surprising.
    • Word of God states Sexy Silvia and Wonder-Cheerleader (an Expy of the former) are actually the same person, which would make her full name Silvianne "Silvia" Lumiere. Joe is even directly mentioned during one of Wonder-Pink's failed QTE sequences, alluding to the third Viewtiful Joe game that was never made.
  • Way back in the Amiga days, Super Turrican took place on the planet of Katakis. This was referenced in the Turrican clone Hurrican, which took place on the planet Takatis (which was the name of a clone of Katakis by the same team, Poke53280).
  • In the Ultima series, Britannia has featured a few heroes from other worlds, including Seggallion, the hero of Origin's Knights of Legend, set in the world of Ashtalarea, Gorn, the hero of Origin's The Quest and Ring Quest, set in the world of Balema, and the fighter Gertan, hero of the Apple ][ game The Caverns of Freitag. The Kilrathi ship in Ultima VII and the Trilkhai in Ultima Underworld II link Ultima to Wing Commander. Serpent Isle would have featured a stranded Kilrathi pilot on the isle of Claw. Ultima Forever would have featured an island with a Kilrathi monument and an island with a crashed Dralthi ship.
  • Again, par for the course regarding Super Robot Wars, due to their Mega Crossover nature, but the specific example goes to Super Robot Wars Original Generation, having the unenviable task of integrating the countless Original Generation stories from previous Super Robot Wars installments into a cohesive Ultimate Universe, often filling in the blanks left by licensed characters with its Original Generation. For example, the "Choukijin" from Super Robot Wars Alpha were originally connected to the Mazinger Z mythos; in Original Generation, they were created to combat the Einsts from Super Robot Wars Compact 2. A later Original Generation installment, including at least one licensed saga, places more emphasis on space-time dimensional elements, a handy way of working in anything that can't be shoehorned in thoroughly into main continuity, but also working around obstacles that might violate pre-established canonicity. From there, the Endless Frontier games tie it to Namco × Capcom and the Xenosaga series, then they all ended up in Project X Zone.
  • Several Sony Online Entertainment employees have joked that their zombie apocalypse sandbox game H1Z1 and their MMOFPS Planetside 2 exist in the same universe, where Planetside is a Lost Colony of escapees from H1Z1. The Nanite Systems Mega-Corp that makes vehicles and weapons in Planetside appear in H1Z1, apparently as a pharmaceutical company. The New Conglomerate Mega-Corp likewise appears in H1Z1 as a manufacturer of bluejeans. However, in practice it is just a Production Throwback.
  • Deconstructed while being Played for Drama in the Story Mode of Mortal Kombat vs. DC Universe. As a result of Shao Kahn and Darkseid merging (by accident, after being beaten by Raiden and Superman in their respective universes) to become the entity known as Dark Kahn, their mere existence is causing both Mortal Kombat's universe and DC's universe to become one. At first this is seen as heroes and villains crossing over to the other's universes to fight one another, until both factions travel to Outworld/Apokolips, where they see the damage that is being done to their universes by Dark Kahn after he had manipulated them all into fighting one another to make him stronger. By the end, however, Raiden and Superman team up to take out Dark Kahn and their universes separate.
  • In the Wing Commander series, Wing Commander Secret Ops and the Wing Commander: Arena manual mentions the WEC, the Corporatocracy of the Crusader series.
  • Ubisoft's Assassin's Creed and Watch_Dogs take place in the same universe. This was first shown in Assassin's Creed IV: Black Flag having an in-game email from Blume, a security firm from Watch_Dogs, proposing Abstergo Industries make use of their ctOS system. Furthermore, the COO of Abstergo Entertainment from the same game is said to gone missing suddenly after a business meeting in Chicago, the setting of the first Watch_Dogs. In that game it turns out the Assassins hired Aiden Pierce to take care of the COO for them. While some players of both games originally assumed these to be nothing more than easter eggs, Assassin's Creed Origins makes the connection of their universes 100% certain by confirming that yes the mission where Aiden kills the COO of Abstergo Entertainment is part of the official Assassin's Creed canon.
  • If the quote is any indication, Command & Conquer: Red Alert was about to be welded with the Command & Conquer: Tiberian Series before going off the rails and becoming its own universe.
    Nadia: This temporary chaos in Europe would only serve to fuel The Brotherhood's cause...
    The Advisor/Kane: ...The temporary future? Comrade chairman, I am the future!
  • In Bravely Second, players can obtain a high-level staff known as Musashi's Oar from a blue treasure chest in the Witherwoods. The weapon in and of itself alludes to the oar Musashi famously used in his duel against Kojiro Sasaki, with its description noting Musashi to hail from the island nation of Wa (which vanished centuries before the time of Bravely Default). The last sentence of the account states "No record remains of his death, but it is said that he was summoned to be a hero for another world." This is a reference to one of Square Enix's lesser-known titles from their Squaresoft days, Brave Fencer Musashi—specifically the Hero Summon ritual (or "Vocatus Heroa" as it's referred to as in Samurai Legend). The implication is that the Musashiden games, or at least their version of Musashi, are therefore canon to the setting of the Bravely series—an interesting thought given that the Big Bad of Samurai Legend is actually the real-life Kojiro Sasaki, never mind a presumably different Kojiro from Musashi's home world serving as his rival throughout BFM.
  • Bioware has confirmed that Dragon Age and Mass Effect take place in the same verse, and have started to offer proof of it in the games. Sharp-eyed players of Dragon Age: Inquisition may notice the head of a krogan mounted in the trophy hall at the Winter Palace. Additionally, in-game information files in one of the Mass Effect games show the world of Thedas, which is considered off-limits for landing parties due to the unpredictable phenomenon of the Blight. Word of God also confirms that Shepard, the hero of the original Mass Effect trilogy, is a direct descendant of the Inquisitor.

    Web Comics 
  • The MS Paint Adventures series Problem Sleuth was tied into the earlier Jailbreak series when Zombie Ace Dick and his whale crashed into the jail where Jailbreak was set. Indeed, a dead whale was part of an early Jailbreak puzzle, and ZAD and the Completely Sane Man were revealed to be the skeletons in one of the cells.
  • Homestuck's Comic Within A Comic Sweet Bro and Hella Jeff predates Homestuck. It was originally written as a parody of another webcomic called Higher Technology, and was written into Homestuck as a webcomic run by Dave Strider.
    • In a semi-canonical donation extra the Problem Sleuth characters did battle with the Midnight Crew. That gang would later become extremely plot important in Homestuck. Even though both Problem Sleuth and the Midnight Crew exist as fictional works in the Homestuck universe — in fact, instead of Homestuck, in-universe the adventure following Problem Sleuth was based on The Midnight Crew. To confuse the issue further, an Easter Egg in Homestuck implies that Problem Sleuth took place on Prospit, making Problem Sleuth canonical to the Homestuck multiverse.
  • In Starslip Crisis, the character of Vore is all but explicitly stated to be in fact Vaporware from the author's previous comic, Checkerboard Nightmare. However, this can be considered only to be a partial example, since said strip's events are never mentioned in Starslip and Vore himself seems to have lost his memory up to that point, causing a bit of a personality change (yes, Vaporware also expressed desires to exterminate mankind, but Vore's a lot more proactive about it), so for all intents and purposes Vore can be considered a separate character. Eventually he did regain his old memories and personality, and started calling himself Vaporware again...right before he was killed off for real. But records of the past (or Real Life, 21st Century Earth) seem to be extremely sketchy, as evidenced by the Show Within a Show "Concrete Universe," where covered wagons exist at the same time as cloning.
  • Crossover Wars and The Crossoverlord established many webcomics as part of the same multiverse with rules more akin to Westphall's mind. The Realitease page done by Crossoverlord creators contains interesting informations about which webcomics happens in the same universe with lists of proofs and explanations:
  • Heroes Unite did it with a horrifying amount of Super Hero webcomics, hosted on Drunk Duck. First it established that Energize, Bombshell, and an alternate counterpart of Acrobat share an universe, and then a bunch of other superheroes joined in. Some writers even took an advantage of it to make their webcomics more popular. The creators of Energize and Dasien did a short (currently on hiatus) crossover between their characters, while the former used a new Shared Universe to bring back his other webcomics - Fearless, SHELL teamed up with The Blonde Marvel and Bombshell and gets his ass kicked by one of Hero Force members before joining HU, and Vora, Princess Of The Skies, appeared a few times in HU before getting her own adventures. And it's all one reality in the webcomics multiverse. Having kickstarted the whole superhero crossover thing on Drunk Duck, Heroes Unite is now set in its own self-contained universe, but the crossover goodness continues in the spinoff Heroes Alliance with the characters from Karabear Comics Unlimited and even involved Jenny Everywhere and golden age characters like Madame Fatal.
  • T Campbell has done this with various webcomics he's written or co-authored, both played straight and using alternate versions of characters.
    • Penny and Aggie, Cool Cat Studio and Sketchies are set in the same universe. However, the SF and supernatural elements in Cool Cat Studio are absent from the other two comics. Campbell once explained this on the P&A forum by stating that such elements exist on the periphery of the comics' shared universe, so not all its inhabitants experience, nor are even aware of, such things.
    • This is in contrast to the Fans! universe (and its alternate versions of P&A's characters), where, particularly after the Revival, paranormal occurrences are so frequent and prominent that the entire world is aware of them. Also, alternate versions of characters from Penny and Aggie and Fans! appear in each other's universes every so often.
  • Barry T. Smith's Ink Tank appeared to be in an entirely new universe from the previous strips...until a story arc which ended with the Author Avatar having a nervous breakdown was resolved by Dante from Angst Technology turning up and treating him to a coffee.
  • Artist Ursula Vernon's Digger, an anthro adventure about a mildly cynical wombat and a statue of the god Ganesh, has this if you start reading her other work. An awful lot of everything she's done seems to have characters in common with the Gearworld, her vaguely-steampunk clockwork-labyrinth art-and-fiction setting. It's only vaguely hinted at in Digger itself.
  • Sugar Bits might have done it when one of the villains summoned Red and The Big Bad Wolf from Ever After to fight protagonists. However, given the nature of the Sugar Bits world and Bleedman's own words, those two comics may or may not share an universe and this will remain unresolved until Endling, creator of Ever After, will confirm it.
  • Shaenon Garrity's Narbonic and Skin Horse were officially confirmed to take place in the same continuity with the introduction of Artie Narbon to Tip Wilkin. Garrity had previously revealed in Narbonic Director's Cut that the main Narbonic characters, Dave, Helen, and Mell, came from three different comics she had drawn in high school and college. Mell also gets her own Spinoff Babies comic, Li'l Mell, and a character introduced in that comic has now shown up in Skin Horse. Garrity's lesser-known Smithson may fit into the same continuity as well; minor character Queensbury Joe appears to be the older version of Homeschool Joe from Li'l Mell.
    • Mel has also appeared twice in Everyday Heroes - once in a brief flashback where Mr. Mighty thwarts one of Helen's capers and again where she appears as Dr. Unpleasant's lawyer.
  • Eli Parker created several different web projects, including Too Far (a comedy space opera webcomic), Powerup Comics (a Stealth Parody of Two Gamers on a Couch webcomics), and These Web Comics Are So Bad (another Stealth Parody, this time of webcomic review blogs). Then Parker created Unwinder's Tall Comics, which included cameos from all of the above, establishing that they (or at least their fictitious authors) all exist in some sort of continuity.
  • There was earlier hints about Bob and George and its fancomics/subcomics taking place in the same multiverse. Ridiculous amount of cameos got finally an explanation, when Rick O'Shay and Chick-Bot appeared in the main comic to tell the true nature of White Space. It was a demi-plane that connected all the universes together. It was later abused by sending all the Mega Mans and other characters into one universe, to fight Bob.
  • Glorianna and Sparky of Lady Spectra & Sparky shared an adventure when Glorianna was briefly transported to the 21st century (while Lady Spectra ended up in Glorianna's era).
  • Anna/Susan from Sire showed up in Evil Plan, where it was revealed that they are the cousin of Hero Antagonist Kevin Kolton. Characters from Evil Plan and Mortifer have shown up in each others' works, and Agent/Andrew Cross shows up in both Evil Plan and morphE.
  • In Spinnerette there are a few arcs centered around Hell and its inhabitants, where we meet Minerva's friends Tom, Kia, Lucretia, and Guinness, all hailing from Krakow. Whether the Marilith duology and Charliehorse are also part of The 'Verse is unknown.
  • Played with in the various Alternate Universe comics for Darths & Droids, where sources that aren't extensive franchises are sometimes "planned" to be continued with other works (either thematic or from the same creator) according to their FAQs. Of course, all of these comics are one-shots, and how these instances of canon welding could actually play out is left to the readers' imaginations. Now for the complete list of proposed merged canons...

    Web Original 
  • Any Journal Roleplay, MUSH, or similar roleplay which allows characters from multiple works of fiction must in some way explain how the crossover occurs. While the Inn Between the Worlds or the "spooky jamjar," in which the various characters somehow travel or are transported from their home settings into an original setting, is probably most common, some roleplays opt instead to adapt the source works into a single shared world. This is especially common for roleplays themed around a specific genre or franchise: notable examples include Mega Man MUSH, Persona MUSH, Super Robot Taisen MUSH and its Spiritual Successor Super Robot Wars MUSH, Videoland MUSH, and many others.
  • The Spectacular Gargoyles combines the settings of Gargoyles and The Spectacular Spider-Man.
  • Mahou MUSH is a Magical Girl-themed game set in Tokyo, the setting of which adapts many magical girl series (and a number of original player-created themes) into a single continuity. Prominent themes thus adapted include Magical Girl Lyrical Nanoha, Puella Magi Madoka Magica, various Pretty Cures (particularly Happiness Charge Pretty Cure), Sailor Moon, and Shugo Chara!.
  • The (In)Famous David Gonterman, Ed Wood of the World Wide Web and the Internet's Most Dangerous Cartoonist; reuses characters, concepts and names so often that it more or less seems that every single thing he's ever written or drawn are all set in the same vague universe/multiverse. This may be partially intentional, but, well...
  • That Guy with the Glasses likes this trope, finally creating an official merging of every TGWTG-involved character during the huge anniversary brawl, and again during Kickassia, Suburban Knights and To Boldly Flee, plus the millions of crossovers between producers. The Nostalgia Critic took this a step further and incorporated Doug himself into the mix, crossing over with his vlogs.
  • The Fear Mythos incorporates The Slender Man Mythos into their canon, as well as the Black Dog from folklores of the British Isles, and later incorporated the Smiling Man from The Jeanette Experience as a Canon Immigrant. The Cthulhu Mythos is a part of it too, with the blog Mephi, having many of Lovecraft's creatures being a major part of the story. The Fear Mythos and Sleeper Mythos are also an example of this, while the Fear Mythos and The Arkn Mythos are an inversion (depending on who you ask, as the exact history of the latter is disputed and unclear). The Fear Mythos as a whole was created from several separate Slender Man Mythos spinoffs, then separated into countless canons as the authors of each story see fit.
  • The Friends and the High Council WMG is an attempt to do this with every Disney-owned property.
  • A Youtuber named PopularMMOs has a series called The Crafting Dead. In the third season, he puts Dr. Trayaurus, of TheDiamondMinecart fame into the series. Before him, he puts Captain Cookie, from Epic Proportions, another series by the youtuber, became part of the story.
  • Pokémon World Tour: United establishes in its first episode that the series takes place twenty years after the events of the Pokémon Red and Blue video games, with Red being a Pallet Town hero and Blue being the first Gym Leader Rose and Cobalt face. However, the end of act one reveals that the new regime of Team Rocket is led by characters from the Pokémon anime, specifically Jesse and James. Further, other characters from the anime, Butch and Cassidy, are aligned with a separate faction of Team Rocket that's A Lighter Shade of Black. Later, when exploring the old Rocket hideout in the Celadon City Game Center, Cobalt uncovers a document describing the new regime's rise in power, which includes mentions of Ash and his frequent battles with grunts Jesse and James and their talking Meowth. This all amounts to show that, in this version of the Pokémon universe, the events of the game and the events of the anime both occurred.

    Western Animation 

Alternative Title(s): Inevitable Crossover, The Moorcock Effect


Example of: