History Main / CrisisCrossover

** ''Film/SpiderManNoWayHome'' is smultaneously a Crisis Crossover ''and'' an Intercontinuity Crossover. It brings together the casts of the MCU ''Spider-Man'' and ''Doctor Strange'' films. But it also unites the MCU incarnation of Peter Parker with his two [[Film/SpiderManTrilogy cinematic]] [[Film/TheAmazingSpiderManSeries predecessors]] and pits them against a LegionOfDoom consisting of most of their villains. [[spoiler: It also crosses over with Film/SonysSpiderManUniverse with a mid-credits cameo of Tom Hardy's Eddie Brock and Venom.]]

** ''Film/SpiderManNoWayHome'' is a Crisis Crossover uniting the MCU Spidey with his two [[Film/SpiderManTrilogy cinematic]] [[Film/TheAmazingSpiderManSeries predecessors]] and pitting them against a LegionOfDoom consisting of most of their villains. [[spoiler: It even ties in Film/SonysSpiderManUniverse with a mid-credits cameo of Eddie Brock and Venom.]]

* ''WesternAnimation/SpiderManTheAnimatedSeries'': While the show had many crossovers, the series had two of this nature near the end of it's run. "Secret Wars" which saw Spider-Man drafted to be a leader in a literal battle of good vs evil where he picks the Fantastic Four, Storm, Captain America, Black Cat and Iron Man to help take on the likes of Dr. Doom, Dr. Octopus, The Lizard, Alister Symthe and Red Skull. The final arc of the series, "Spider Wars", saw him teaming with various Spider-Men from different alternate universes (one with eight arms, one with Doc Ock's metal tentacles, one who was a billionaire and built his own tech, one who didn't have any powers, and one who was the Scarlet Spider) to stop Spider-Carnage, a murderous version of Spider-Man who fused with the Carnage symbiote.

->''"So first there was ComicBook/TheInfinityGauntlet, then ComicBook/[[TheInfinityWar Infinity War]], and now there's [[ComicBook/TheInfinityCrusade Infinity Crusade]]. It must be like an annual convention for super heroes that Warlock runs for them. It gives them all a chance to get together and network and catch up on each other's continuity, exchange business and trading cards, pose for holograms with each other, stuff like that. They probably just wish the things were held in San Diego or someplace fun, where everyone could hang out at the beach."''

->''"So first there was The Infinity Gauntlet, then Infinity War, and now there's Infinity Crusade. It must be like an annual convention for super heroes that Warlock runs for them. It gives them all a chance to get together and network and catch up on each other's continuity, exchange business and trading cards, pose for holograms with each other, stuff like that. They probably just wish the things were held in San Diego or someplace fun, where everyone could hang out at the beach."''

* The ''Franchise/PrettyCure'' MagicalGirl metaseries have their own Crisis Crossover movie series labeled "Pretty Cure All Stars", featuring heroines from all series released until then.

** CrisisCrossover/DCComics
** CrisisCrossover/MarvelUniverse

** CrisisCrossover/MarvelComics

[[folder:DC Comics]]
* ''ComicBook/CrisisOnInfiniteEarths'' (1985): The trope namer. Before [=CoIE=], there were [[AlternateUniverse two major and nearly a dozen minor separate DCU "Earths" (read: realities)]], each with its own continuity. They didn't cross over, except when they did (or when a DC writer forgot who was supposed to be on which Earth and a DC editor didn't catch the goof). Afterwards: one Earth, one reality, and the biggest {{retcon}}ning of past events ''ever''. Let one example serve for all: Pre-Crisis, there was Kara Zor-El, better known as Comicbook/{{Supergirl}}. During Crisis, she died. Post-Crisis, she had [[RetGone never existed]] due to the edict that, following the ''Man of Steel'' [[ContinuityReboot reboot]], Superman was to the only surviving Kryptonian (although she did appear in the final arc of Peter David's ''ComicBook/{{Supergirl}}'', "Many Happy Returns" and other places). To this day, nobody (save for a few people, namely Donna Troy and The Spectre) remembers her as she was then, though a new version of the character returned in ''Comicbook/SupermanBatman: The Supergirl from Krypton'' in 2005 and her death was retconned in the ''Comicbook/{{Convergence}}'' event. The first act of the "Multiverse Saga" dealing with the "Death of the Multiverse".
* ''ComicBook/LegendsDC'' (1987): This series was a crossover in which the evil god ComicBook/{{Darkseid}} tries to turn humanity against all its superheroes; it doesn't take. ''Legends'' was most notable for launching the semi-humorous ''[[ComicBook/JusticeLeagueOfAmerica Justice League International]]'' (the one with Comicbook/BlueBeetle) and the perennially popular supervillains-doing-espionage title ''ComicBook/SuicideSquad'', as well as starting the career of third Franchise/TheFlash, ComicBook/WallyWest. It also marked the post-Crisis debuts of Franchise/WonderWoman (after she was rebooted from scratch by George Perez and Greg Potter) and [[ComicBook/{{Shazam}} Captain Marvel]].
* Three events in 1988:
** In ''Cosmic Odyssey'' (ironically the only one that was self-contained), Darkseid, the ComicBook/NewGods, and a group of super-heroes fight a giant shadow that Metron claims is the Anti-Life Equation's true form. Outside of [[Franchise/GreenLantern John Stewart]] (no, not ''[[Series/TheDailyShow that]]'' one) acting like a rookie and causing an entire planet to explode due to his hubris, [[CanonDiscontinuity no one likes to talk about this story]] since making the Anti-Life Equation a giant shadow monster was a stupid idea.
** In ''Comicbook/{{Millennium}}'', the robotic Manhunters try to stop the Guardians of the Universe from giving a group of really bad ethnic stereotypes virtual Godhood; it doesn't work out. By contractual obligation, at least one secondary character from most of DC's titles turned out to be [[TheMole the Manhunters' moles]][[note]](In ''Superman'', basically all of Smallville but the Kents.)[[/note]], which was never mentioned again afterwords.
** In ''Comicbook/{{Invasion}}'', a whole mess of alien planets get together and try to take over Earth to keep all the superbeings we keep producing under control; yet again, it doesn't work out. This crossover also introduced the Metagene MetaOrigin concept in the DCU, as well as led to the launching of [[WestCoastTeam Justice League Europe]] and L.E.G.I.O.N., a 20th Century ''Comicbook/{{Legion of Super-Heroes}}'' spin-off title known mainly for having Lobo and Brainiac 2 on the roster.
* Two in 1991:
** ''War of the Gods'' wasn't a bad idea in theory: All the different godly pantheons in Franchise/TheDCU (the ComicBook/NewGods, plus the Olympians, the Asgardians, etc.) have at it and the various divinely-powered superheroes (Wonder Woman, Captain Marvel, etc.) get caught up in it. Unfortunately, writer George Perez made the mistake of double-booking himself drawing Marvel's ''ComicBook/TheInfinityGauntlet'' and writing/drawing ''War of the Gods'' at the same time, leading to ''War of the Gods'' suffering from bad writing.
** ''ComicBook/{{Armageddon 2001}}'': One of DC's top super-heroes will become the uber-villain "Monarch"! Except the ending (it was ComicBook/CaptainAtom) gets leaked, meaning [[ShockingSwerve third-string character Hawk became Monarch instead]]. Monarch promptly disappeared until three years later, when he was retooled as Extant and became a flunky for A-List hero [[Franchise/GreenLantern Hal Jordan]], who went evil in the wake of ''ComicBook/TheDeathOfSuperman''.
* ''Eclipso: The Darkness Within'' (1992): Over the summer, DC retconned a B-List villain from the '60s into a serious threat capable of possessing anyone -- up to and including Superman. Very little changes, other than the [[spoiler: HeroicSacrifice of Starman IV -- whose book had been canceled anyway (and it apparently [[BackFromTheDead didn't take]])]]. Eclipso himself got a series out of it for about two years, notable as one of the few mainstream comic series with a villain as its protagonist at the time.
* ''Bloodlines'' (1993): Whether you like this or not all depends on if you're a fan of UsefulNotes/{{the Dark Age|of Comic Books}}. This was a CrossThrough of all of DC's Annual series for 1993. A race of [[Franchise/{{Alien}} Xenomorph-like]] parasites invade and start killing people by draining their spinal fluid. A small percentage of people, however, gained superpowers by this, leading to the creation of a new bunch of {{Nineties Anti Hero}}es. Nothing really changed and these new heroes were eventually reduced to [[CListFodder cannon fodder]] for ComicBook/InfiniteCrisis, or else ending up in ComicBookLimbo. The only notable result from this crossover being Creator/GarthEnnis' ''Comicbook/{{Hitman}}''. Aside from that, it's probably best remembered for crossing over with two far-better known DC stories from the same time period: ''ComicBook/TheDeathOfSuperman'' and ''ComicBook/{{Knightfall}}'', due to featuring the four replacement Supermen and the Azrael-Batman for most of the crossover.
* ''ComicBook/ZeroHour: Crisis in Time'' (1994): For this one, DC ended up pressing the reset button ''again''. WellIntentionedExtremist Parallax (a.k.a. [[Franchise/GreenLantern Hal Jordan]]) plans to destroy the entire DC Universe and remake it [[SetRightWhatOnceWentWrong in his image]]. Unlike ''ComicBook/CrisisOnInfiniteEarths'', ''Zero Hour'' ended up changing relatively little (aside from completely rebooting the Comicbook/{{Legion Of Super-Heroes}} and making ComicBook/{{Hawkman}}'s continuity [[ContinuitySnarl even more confusing]]) and a massive bus being dropped onto the Justice Society of America. And unlike ''ComicBook/CrisisOnInfiniteEarths'', ''Zero Hour'' was met with mixed reviews.
* ''Worlds Collide'' (1994): This was a major DC Comics[=/=]Creator/MilestoneComics crossover, which had to be handled carefully, since the DC characters were comics in the Milestone universe. It was a scintillating series in that the differences between similar characters such as Superman and ComicBook/{{Icon}} were examined. Perhaps the most entertaining was the relationship between Comicbook/{{Hardware}} and ComicBook/{{Steel}}, who had the same abilities and skills, but were at opposite ends of the SlidingScaleOfIdealismVersusCynicism. Since then, Milestone was folded into the DC universe, which seems even more poignant after the passing of Creator/DwayneMcDuffie.
* A more straight example for Milestone was ''Shadow War'', which included all of the titles in the line, using it to introduce titles like ''ComicBook/{{Xombi}}'' and ''Kobalt''.
* 1995's ''ComicBook/UnderworldUnleashed'' saw Mark Waid killing off 90% of Franchise/TheFlash's rogue's gallery who he felt were too silly even for his [[UsefulNotes/TheSilverAgeOfComicBooks Silver Age]] tastes (though this didn't last long and Waid was proven wrong in a BIG way later on) and introducing Neron, the ''de facto'' Satan of the DC Universe proper. It also saw a ton of DC villains [[DealWithTheDevil selling their souls]] for grim and gritty revamps, of which only a small handful actually stuck.
** In the afterword to the collected edition, Waid claims that killing and resurrecting the Rogues was the plan all along in order to protect them from unnecessary DarkerAndEdgier revision:
---> Brian and I arranged for them to [[DeathIsCheap lie low in hell for a little while]], if only to keep some knuckleheaded creator from, oh, say, turning Heat Wave into a ''living pillar of fire''.
* ''ComicBook/FinalNight''[[note]]Not to be confused with either ''ComicBook/FinalCrisis'' or ''ComicBook/BlackestNight''[[/note]] (1996): is probably the most fondly-remembered crossover from the 1990s, most likely because the whole thing became one huge AuthorsSavingThrow/Last Hurrah for Hal Jordan (writer Karl Kessel agreed to write the story for DC on the condition that he could give Hal a mercy killing/[[RedemptionEqualsDeath heroic sacrifice death]]). An alien weapon called a [[Comicbook/{{LegionOfSuper-Heroes}} Sun-Eater]] arrives in the solar system and, [[ExactlyWhatItSaysOnTheTin surprisingly enough]], [[PlanetEater eats the sun]]. After Earth's heroes try to keep their sunless world alive, [[ComicBook/GreenLantern Hal Jordan]] make a HeroicSacrifice to rekindle the sun and redeem himself (of course, RedemptionEqualsDeath). Also, the Post-Zero Hour Legion meets everyone in the DC Universe proper for the first time -- and before his death, Hal resurrects ComicBook/GreenArrow off-panel, or rather shoehorned in retroactively in-panel by Creator/KevinSmith about three years later. [[ComicBookTime Realtime]], of course.
* ''Genesis'' (1997): John Byrne "kills off" Darkseid in a lame plot where the Source Wall breaks and everyone's powers start acting wonky. [[VillainDecay Nobody cares]]. Moving on...
* ''ComicBook/DCOneMillion'' (1998): All DCU books stopped and became "<Title> #1,000,000" as the JLA and the rest of the DC Universe go into the future to fight Solaris the Sentient Sun, who wants to kill his creator Superman. As Creator/GrantMorrison stories go, you'll either love it or hate it. This crossover is ''certainly'' part of the main DCU canon (Hourman One Million becomes a major player in JLA, JSA and his own book). (The final issue of Morrison's later ''ComicBook/AllStarSuperman'' features the present-day Solaris, and acts as a kind of origin story for the future society depicted in ''One Million'' -- or rather, presumably an alternative version of that future society, since ''All-Star Superman'' is definitely ''not'' part of the main DCU canon.)
* ''Day of Judgment'' (1999): Featured a then unknown Creator/GeoffJohns writing a story where the demons Neron and ComicBook/{{Etrigan}} steal the nigh-omnipotent powers of the Spectre. HilarityEnsues, and the ghost of Hal Jordan ends up becoming the new Spectre. Led to the creation of the Sentinels of Magic - a group of DC's mystic heroes who then appeared absolutely nowhere.
* ''Sins of Youth'' (2000): In an effort to promote ''ComicBook/YoungJustice'', DC produced this series, which was a special Crisis Crossover in which Young Justice, the JLA, the JSA, the Titans and as many others as the pencilers could cram into frame descended on the National Mall in Washington, D.C., for a rally, only to face the mother of all FountainOfYouth plots wherein nearly every character present was aged or de-aged. It only interrupted the monthly run of ''YJ'' and crossed over into ''Superboy'', and was over within a month real-time, but the scale of the story and the villains' plot was worthy of this trope.
* 2001 had two events:
** ''ComicBook/OurWorldsAtWar'' featured an OmnicidalManiac trying to destroy the universe via destroying Earth (with Brainiac-13 pulling up the rear to exploit the madness) and the entire universe teaming up in a galactic alliance to save the universe. Infamous for it's massive number of deaths (Guy Gardner, Martha and Johnathan Kent, Aquaman, Sam Lane, and Wonder Woman's mom Hippolyta), just about all of which were overturned, with Gardner and the Kents being upgraded to living within months of the storyline ending.
** ''ComicBook/JokersLastLaugh'', tied very much to the other crossover (almost literally starting after ''Our Worlds At War'' had ended). This story had Joker infect all of the DC Universe's villains with chemicals turning them into Joker-lite mass murderers, after Joker is [[InducedHypochondria falsely told he has terminal cancer]]. Two notable scenes are when Joker Lampshades previous crises by desiring red skies for his plan, and Chuck Dixon spending the entire storyline effectively cursing out readers for asking why no one kills the Joker.
* ''ComicBook/IdentityCrisis'' (2004): This was the first book to use "Crisis" in its title since ''Zero Hour''. It was a crossover, but not necessarily a ''crisis'' crossover -- in fact, it was a very low-key murder mystery far more concerned with buried secrets and the personal lives of heroes than with blowing stuff up -- but it did end up changing things, due to the nature of the secrets revealed rather than any cosmic shenanigans. It's also notable as it deretconed back into existence many pre-ComicBook/{{Crisis|on Infinite Earths}} story lines from the Silver and Bronze ages, but at the same time made them DarkerAndEdgier. It turned B-list Comicbook/TeenTitans Villain Dr. Light into a [[MemeticMolester rapist]], [[RetCon revealing]] that his "bumbling" and "pathetic" status was the result of a magically-induced lobotomy. The story was eventually revealed to be the first part of a trilogy to "explore the DC heroes" in which they were put up against "a very personal threat". Its repercussions were felt throughout Franchise/TheDCU (leading to mini-Crisis Crossovers such as ''[[ComicBook/SecretSix Villains United]]'' and the ''Day of Judgement'' sequel ''[[ComicBook/{{Shadowpact}} Day of Vengeance]]'') until they coalesced in:
* ''ComicBook/InfiniteCrisis'' (2005-2006): Refugees from the original ''Crisis'', who had been watching the DCU since, had decided that the events of ''Identity Crisis'' and the things that followed were the last straw, and returned to the universe to "set things right". As their version of setting things right involved destroying reality and replacing it with a "better" one, the current inhabitants of the DCU were less than pleased with the plan. Fighting ensued, and in the end a "soft reset" occurred -- some things were changed but by and large, continuity remained the same (except for the Comicbook/{{Legion Of Super-Heroes}}, which received its second complete reboot) -- and the multiverse, gone since the pre-ComicBook/{{Crisis|on Infinite Earths}} days, returned. Served as the second act of the "Multiverse Trilogy" as the "rebuild of the Multiverse" and the second act of the "Exploration Trilogy" by "putting the greatest odds against the heroes". Was immediately followed by:
* ''ComicBook/FiftyTwo'' (2006-7): Basically the final act of the storyline of ''ComicBook/IdentityCrisis'' and ''ComicBook/InfiniteCrisis'' (story-wise). Innovative for its use of real time continuity, tossing ComicBookTime out the window in favor of the ''Series/TwentyFour'' approach, published weekly, from May 2006 to May 2007, each issue represents a week of time in-universe, covering the "missing year" of the DCU, as after ''Infinite Crisis'', all books were jumped forward "One year later". Written by a "dream team" of four writers (Creator/GeoffJohns, Creator/GregRucka, Creator/MarkWaid, and Creator/GrantMorrison) each of whom contributed something to every issue. It also followed the lives of minor characters of the DCU while the "Big Three" Batman, Superman, and Wonder Woman took the year off for various reasons, Widely considered to be one of the greatest story lines of UsefulNotes/{{the Modern Age|OfComicBooks}}. It also introduced the Modern Batwoman, and Renee Montoya as ComicBook/TheQuestion.
* ''ComicBook/CountdownToFinalCrisis'' (2007-2008): Meant to act as a bridge between ''52'' and ''Final Crisis''. It's remembered as "one of the worst comic storylines of all time", having by hampered by massive ExecutiveMeddling, which led to an oversaturation of tie-ins resulting in even worse ArchivePanic (How bad? Another reviled event comic, ''ComicBook/AmazonsAttack'', ties into it... and that event has tie-in issues of its own!), and the main comic itself was riddled with plotholes and bad art. DC quickly worked to move the whole mess into CanonDiscontinuity.
* ''ComicBook/FinalCrisis'' (2008): Picking up at the end of the year-long weekly series ''Countdown to Final Crisis'' and a mounting sense of crossover fatigue among fans, it faced an uphill battle, but the strength of its writer and artist (Creator/GrantMorrison and J. G. Jones) saw it through to sales success. The newly reincarnated Darkseid [[RescuedFromTheScrappyHeap accomplishes his goal of ruling the human race]] as he unleashes the Anti-Life Equation on Earth, plunging Earth into a black hole that threatens to destroy the Multiverse. The heroes save all of existence, but at the high cost of several high profile casualties (including ComicBook/MartianManhunter and Franchise/{{Batman}}) and lots of dead civilians who died while Darkseid reigned. Served as the final acts of the "Multiverse Trilogy" ("the [[TitleDrop Final Crisis of the Multiverse]]") and the "Exploration Trilogy" ("the day that evil won").\\
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''Final Crisis'' itself is a ''huge'' crossover dealing with multiple stories. In addition to the event proper, there was ''Final Crisis: Rogues' Revenge'' where the Flash's RoguesGallery reject Libra's invitation to the new [[LegionOfDoom Secret Society]] and kill the murderous speedster Inertia just before the events of Final Crisis begins; ''Final Crisis: Revelations'' which takes place during Darkseid's siege of a controlled Earth as seen by the Spectre and the Question; and ''Final Crisis: Legion of Three Worlds'' (taking place after all the previously listed ) which has the titular [[Comicbook/{{LegionOfSuper-Heroes}} 3 Legions]] fighting against Superboy-Prime and a new Time Trapper and his army of villains before being revealed as an older version of Prime, which ultimately lead to Prime returning powerless to his reconstructed Earth (but having to face the sins of his actions while in the Multiverse).
* ''ComicBook/BlackestNight'' (2009): Following on from the events of the epic ''ComicBook/SinestroCorpsWar'' storyline that [[EnsembleDarkhorse proved to be infinitely more popular]] than the ''Countdown'' event that was happening at the same time, the culmination of a prophecy first mentioned in an Creator/AlanMoore penned back-up strip in "Tales of the Franchise/GreenLantern Corps" back during the 80s. The best way to describe it is as SpaceOpera [[JustForFun/XMeetsY meets]] ZombieApocalypse. As dead super heroes, super villains, and their families and friends are brought back to life by Nekron, the various color corps from Geoff Johns' run on Green Lantern must put aside their differences and fight to protect all life in the universe. While being heavily ComicBook/GreenLantern[=-centric=], it crosses over with the entire DCU. Most books had at least one issue involved with the event.\\
\\
The whole thing was initially conceived as a BatFamilyCrossover in the ComicBook/GreenLantern books, along the lines of ''Sinestro Corps War''. As mentioned, the absolute success of ''Sinestro Corps War'' has lead DC to expand it into a full blown crossover. Even a few canceled books were temporary brought "back to life" for one shot issues just to add to this event. It now seems hard to imagine the relatively simple origins of this event given the hugeness it eventually grew to.
* ''ComicBook/BrightestDay'' (2010): Following up from 'ComicBook/BlackestNight'', this was a year-long event dealing with the newly resurrected characters' attempts to rebuild their lives after being dead, and the quest for the newly created White Light Battery on Earth. In many ways it was more of a CrossThrough; the books involved shared a feeling of making a fresh start but each one mostly followed their own story that was only tangentially connected to the main series.
* ''ComicBook/{{Flashpoint}}'' (2011): This is to Franchise/TheFlash what ''ComicBook/BlackestNight'' was to Franchise/GreenLantern. Barry Allen has woken up to find reality changed around him; now he needs to find out ''what the heck happened?'' His discovery of the truth behind the altered world quickly leads to [[ComicBook/{{New 52}} a line-wide reboot on a scale]] not seen since the original ''Crisis''.
* ''ComicBook/ForeverEvil'' (2013-14): Continuing off where ''ComicBook/TrinityWar'' left off, the Crime Syndicate, the Justice League of a [[MirrorUniverse universe where everyone is evil, has arrived to the prime Earth and knocked the three Justice Leagues out cold in a bid to]] TakeOverTheWorld. [[EvilVersusEvil Not every supervillain is happy about this new development]], least of which is ComicBook/LexLuthor, who leads Earth's native supervillains to stop the Syndicate from destroying what little they all value on Earth.
* ''ComicBook/{{Convergence}}'' (2015): Comicbook/{{Brainiac}} uses his access to the Vanishing Point to pluck cities out of three pre-New 52 eras of DC history (the pre-''Comicbook/CrisisOnInfiniteEarths'' era, the pre-''Comicbook/ZeroHour'' era, and the pre-''Comicbook/{{Flashpoint}}'' era). Additionally, he also captured cities from various {{Alternate Universe}}s from the DC [[TheMultiverse Multiverse]], such as the Creator/TangentComics universe, the Creator/{{Wildstorm}} universe, and the Comicbook/{{Flashpoint}} universe. With 40 captive cities in total, Brainiac takes them to the mysterious world of Telos within domes, to observe them. But when [[Comicbook/TheNew52FuturesEnd Braniac mysteriously vanishes when attempting to gain yet another city from a doomed timeline]], [[GeniusLoci Telos itself]] releases them to see which world deserves to live amongst them all. The ensuing chaos sees a massive conflict that pits hero against hero and spans decades of continuity.
** The 40 tie-in stories this event had were very well received (many of them [[AuthorsSavingThrow brought back beloved characters and status quos]] that hadn't been seen in years or even decades). The main miniseries was much less popular.
** The main effect this event had on the New 52 universe was that the Superman and Lois Lane of the Post Crisis/Pre-Flashpoint Universe immigrated to the New 52 Universe, as seen in ''ComicBook/SupermanLoisAndClark''.
* 2017 brings us two:
** ''ComicBook/DarkNightsMetal'' is the culmination of Creator/ScottSnyder's Batman run, in which the Justice League comes face to face with a "Dark Multiverse" with the crossover restoring many [[TheBusCameBack elements and characters]] that have been missing since the New 52 began.
** ''ComicBook/DoomsdayClock'' is the self-contained example, coming off plot threads that have been built up since the ComicBook/DCRebirth relaunch started, where the DC Universe crosses over with ''ComicBook/{{Watchmen}}''.
* 2018 brings us ''ComicBook/HeroesInCrisis'', which features Superman, Batman, and Wonder Woman investigating a horrible massacre at a getaway designed to help heroes with PTSD.
* 2019:
** ''Event Leviathan'', a noir-inspired arc featuring ComicBook/LoisLane seeking the aid of detective-based heroes to investigate the criminal organization of the same name.
** And that is but ''part'' of the massive ''ComicBook/DCYearOfTheVillain'' storyline which began in May and concludes in 2020, during which the DCU is essentially in a ''permanent'' state of Crisis Crossover.

[[folder:Marvel Comics]]
* ''ComicBook/ContestOfChampions'', the first crossover done as a MiniSeries.
* ''ComicBook/SecretWars1984'' was essentially twelve issues of good guys and bad guys beating each other up in various and creative ways in order to promote a toy line, still, it was a blast. Sometimes you buy a comic to read good guys fighting bad guys. Relatively little impact on the larger Marvel Universe. A few things did change following it:
** She-Hulk joined the ComicBook/FantasticFour, while the Thing remained behind on Battleworld.
** The stage was set for Magneto to lead the ComicBook/XMen (reinforcing NotSoDifferent between him and Charles) in ''ComicBook/SecretWarsII''.
** ComicBook/SpiderMan got his black suit, paving the foundation for ComicBook/{{Venom}} a few years later.
* The sequel, ''ComicBook/SecretWarsII'', was less successful. The Beyonder, the omnipotent being behind ''Secret Wars'', took on human form and wandered around doing stuff, with the heroes making mostly-futile attempts to interfere with him and Mephisto trying to kill him. Generally considered a failure, partially due to its inescapable nature, with nearly every comic Marvel published at the time tying in somehow, and partly because the concept of the Beyonder trying to get used to being a human led to lots of {{Narm}}. A good example of what not to do.\\\
While very little changed in the Marvel Universe following the event, ''Secret Wars II'' is notable as a legal footnote to the ''Franchise/{{Transformers}}'' franchise as featuring an EarlyBirdCameo of [[ComicBook/TheTransformers Marvel Transformers]] antagonist Circuit Breaker. Marvel editor Bob Budiansky gunned for her to debut in this story so that she would become the copyright of Marvel rather than ''Transformers'' owner Creator/{{Hasbro}}, causing the latter's comics partner Creator/IDWPublishing [[ScrewedByTheLawyers no small amount of headaches]] in reprinting Marvel's ''Transformers'' comics in the 2000's.
* The 1986 storyline ''Mutant Massacre'' involved the mass murder of the underground mutant community known as the Morlocks at the hands of the Marauders, a group of mercenaries loyal to Mr. Sinister. This series mainly affected the X-books and their characters (at the time, ''Uncanny X-Men'', ''X-Factor'' and ''New Mutants'') but it also crossed over into ''Daredevil'', ''The Mighty Thor'' and, of all places, ''ComicBook/PowerPack''. It may well be the first crossover which required readers to get every book involved if they wanted to have the full story, a template which almost every crisis crossover has followed since.
* Also worth mentioning are ''Fall of the Mutants,'' in 1987, which was mostly confined to the X-Books; ''Evolutionary War,'' in 1988, which made its way through the Marvel summer annuals and featured the High Evolutionary; 1989's ''Atlantis Attacks,'' also running through Marvel's summer annuals for that year to celebrate the ComicBook/SubMariner's [[MilestoneCelebration 50th anniversary]], as heroes fought off an Atlantean invasion; and other X-Book X-Overs like ''X-Cutioner's Song'' and ''X-Tinction Agenda,'' each of which made significant, if not always lasting, changes to the X-Status-Quo.
* In 1989 came the ''Comicbook/{{Inferno}}'' crossover, in which demons from Limbo staged an invasion of New York City. The storyline was mainly an X-Book storyline, as ''Inferno'' resolved longstanding plotlines involving Jean Grey's [[CloningBlues doppleganger]] Madelyne Pryor, the Madelyne/Cyclops/Jean Grey love triangle, and Illyana Rasputin's ApocalypseMaiden, but the effects of the X-Over was felt in just about every Marvel book published at the time, leading to the introduction of a new Avengers roster, the Thing being restored to human form[[note]]this occurred post-''Inferno'', but was the result of the Human Torch going to his overpowered Nova Flame mode during ''Inferno'' and being unable to power down; when Ben was tossed into the machine being used to restore Johnny's normal state, Johnny emerged in full control of his flame, and Ben emerged a normal human[[/note]], and the Jason Macendale Hobgoblin becoming half-demon (after getting his ass kicked by Harry Osborn, while dressed as Green Goblin).
* Late 1989 and Early 1990 brought the ''Acts of Vengeance''. Loki secretly organized a veritable army of supervillains in what was ultimately a poorly written plotline that suffered from a massive case of writer revolt. Most notable for the storylines that ignored the main plot, where Spider-Man temporarily gets used to his new Captain Universe cosmic powers, the Fantastic Four testify before Congress against the proposed Super Power Registration Act, Psylocke becomes an ninja, and Magneto takes down the Red Skull in a SugarWiki/MomentOfAwesome.
* During 1991-1993, Marvel ran what has since become known as "The Infinity Trilogy"; three X-Overs written by Jim Starlin, involving Thanos, Adam Warlock, Magus, and the Infinity Gems.
** The first installment, ''ComicBook/TheInfinityGauntlet'', did the idea of a crossover right; only a few books were part of the crossover and almost all of them were books with a good reason to be part of the crossover, mainly those that dealt with things of a magical or cosmic bent (ComicBook/DoctorStrange, ComicBook/{{Quasar}}, etc) that the main mini-series was about to begin with. There were only a few anomalies that didn't quite fit, like the Hulk or Cloak & Dagger. Unfortunately, the sequels ''ComicBook/TheInfinityWar'' and ''ComicBook/TheInfinityCrusade'', roped-in practically every single other Marvel title whether it worked or not.
* 1992 saw the Avengers crossover ''ComicBook/OperationGalacticStorm'', in which the team was drawn into an all-out war between the Kree and Shi'Ar galactic empires. It turns out the whole thing was engineered by the Kree Supreme Intelligence, who manipulated the Shi'Ar into detonating a [[NukeEm nega bomb]] to spur the stalled Kree evolutionary process, at the cost of billions of Kree lives. Led to a split in the Avengers' ranks when an Iron Man-led team killed the Supreme Intelligence in retaliation (though they only destroyed a shell), much to Captain America's dismay.
* 1993 brought the Marvel world ''ComicBook/BloodTies'', a sequel to the ''Fatal Attractions'' BatFamilyCrossover that involved both the Avengers and X-Men teams traveling to Genosha to save ComicBook/{{Quicksilver}}'s daughter Luna Maximoff from the predations of the mutant extremist Fabian Cortez. This rescue mission was complicated by the arrival of Exodus, the DragonAscendant to Magneto since ''Attractions'' and a mutant of SuperpowerLottery-level power. Heavyweights from both the Avengers and the X-Men clashed with Exodus, and in the climax he fought off the entirety of both teams singlehandedly before being brought down. Due to the Avengers traveling to Genosha without the approval of the UN, this resulted in them being stripped of their charter and their West Coast team being disbanded.
* The ''ComicBook/AgeOfApocalypse'' crossover ran through the X-Men books in 1995, halting them for six months to tell the story of an AlternateUniverse where ComicBook/{{Legion|MarvelComics}} accidentally kills ComicBook/ProfessorX before he could found the X-Men, leading to an apocalyptic world where ComicBook/{{Apocalypse}} rules everything and Magneto formed the X-Men instead.
* ''ComicBook/TheCrossing'' ran through the Avengers books in 1995 as well. The premise was that Iron Man had been under the mental influence of Kang the Conqueror for years, and had now turned against the Avengers outright; the only way the Avengers could defeat him was to pluck a younger Tony Stark, untouched by Kang, from an alternate timeline, and in the end, "evil" Tony was killed off. This turn of events was [[DorkAge not well-received]], to say the least.
* There's also the ''ComicBook/{{Onslaught}}'' saga in 1996, which was famously [[ExecutiveMeddling hijacked by editorial]] to set up Avengers and Fantastic Four's continuities being rebooted from scratch outside the Marvel Universe via ''ComicBook/HeroesReborn''. However, [[DorkAge this reboot was short-lived]], and the subsequent ''ComicBook/HeroesReturn'' storyline not only brought everybody back, but [[ResetButton undid the damage done by]] ''ComicBook/TheCrossing''. Thank you, [[RealityWarper Franklin Richards]].
* 2001 brought ''Maximum Security'', in which a whole mess of alien planets get together to keep all the superbeings we keep producing under control; however, instead of completely borrowing DC's plot for ''Invasion!'', they simply designate Earth as a penal colony, drop off the scum of the universe to keep the superheroes busy, and have a ship in orbit keep everyone from leaving. The plot sickens when Ego the Living Planet begins assimilating Earth as his new body. Yet again, it doesn't work out -- but the Kree are given a new VoluntaryShapeshifting gimmick... until the next CosmicRetcon.
* The later 2000s brought a whole series of crossovers, collectively tearing down and then rebuilding the superhero community:
** First the BatFamilyCrossover ''ComicBook/AvengersDisassembled'', where Comicbook/TheAvengers start getting attacked on all sides out of nowhere. It's eventually revealed that the assault came from the Scarlet Witch, whose powers had grown to RealityWarper levels and driven her mad. She's stopped and placed in the care of her family (Magneto and Quicksilver), but the losses are so great that the Avengers disband (though the ComicBook/NewAvengers form shortly afterward after a mass supervillain breakout).
** Not long after came ''ComicBook/SecretWar'' in winter 2004-2005. Nick Fury begins to see that more and more D-list villains are hitting the streets with bigger and better tech, far more expensive than their petty crime could ever pay for. Fury realizes that the weapons are coming from Latveria, but the United States has experienced a thawing of relations with the Latverians and the President vetoes his request to attack and put a stop to the armaments. Fury doesn't take no for an answer and gathers the heavy hitters of the Marvel Universe before launching a black ops invasion of Latveria, completes his objectives, then wipes the team's memories to preserve plausible deniability. The cat gets out of the bag when the consequences come home to roost in New York. Fury is forced into hiding until the events of ''Secret Invasion'' while Maria Hill ascends to Director of SHIELD.
** 2005 followed up with ''ComicBook/HouseOfM'', in which Quicksilver manipulates Scarlet Witch to create "a perfect world", which gets over-ridden by Magneto's concept of a "perfect world" being one ruled by mutants. After much fighting, Scarlet Witch comes to the decision that mutantkind still would create a world of violence and hate, and she promptly depowers 90% of the mutant community. At a stroke, mutant-kind is reduced from a population of millions with strong political and economic support to less than 200 frightened heroes on the verge of extinction.
** ''Comicbook/CivilWar'', in 2006. The deaths of the New Warriors and the city of Stamford, Connecticut at the hands of Nitro leads to a backlash against all heroes and a political push to get heroes to register their secret identities with the US Government, via the Superhuman Registration Act. Iron Man and Mr. Fantastic decide to back the new law and lead the charge to do so, while Captain America leads the anti-registration side of the super-hero community, as he sees the whole Registration Act as a bad idea. Needless to say, it all ends in horror as Captain America is defeated, denounced as unpatriotic, and assassinated, and Iron Man being handed full-control over SHIELD.
** This is followed by ''ComicBook/WorldWarHulk'', the follow-up to the ''Comicbook/IncredibleHulk'' storyline ''ComicBook/PlanetHulk'' where, days before ''Civil War'' happened, Iron Man and Mr. Fantastic shoot Hulk into outer space (because, frankly, the conflict was gonna have enough problems ''without'' having to deal with the Hulk). He ends up on a hellish gladiator planet, which soon explodes due to the ship Hulk was sent on blowing up. Needless to say, Hulk is pissed and fans get five issues of Hulk delivering karmic beatdowns towards Iron Man, Mr. Fantastic, and just about anyone else who gets in his way, as well as crossover issues in or with Comicbook/TheAvengers, Comicbook/GhostRider, [[ComicBook/LukeCageHeroForHire Heroes For Hire]], Comicbook/IronMan, ComicBook/AntMan, Comicbook/ThePunisher, and the ComicBook/XMen, not to mention a Prologue issue with a story that features the ComicBook/MiniMarvels filling in the background.
** ''ComicBook/SecretInvasion'', 2008: After the ninja assassin Elektra is killed ([[DeathIsCheap again]]), the Avengers discover that "Elektra" was actually an alien Skrull impostor ''pretending'' to be Elektra. Both characters and fans quickly started wondering who ''else'' could be a fake, fueled by WordOfGod explaining that the infiltration went back for years. On top of all the problems from the last few Crisis Crossovers (Captain America dead, the Avengers fractured and preoccupied with fighting each other rather than actual threats, and the X-Men have had their power drastically reduced), throw in the [[ParanoiaFuel paranoia]] of double agents and it sure would be trouble if the aliens decided to invade now that every force that could be expected to stand up to them has been crippled... Ultimately, while Earth wins, Iron Man is still blamed for [=FUBARing=] the superhuman response, S.H.I.E.L.D. is dissolved, and control of the rest is handed over to the media darling who killed the Skrull queen on live TV; the leader of the BoxedCrook team the ComicBook/{{Thunderbolts}}: Norman Osborn. That's right, the [[Comicbook/NormanOsborn Green Goblin]] is head of the government's superheroes. Yikes.
** This led to a pseudo-example called ''ComicBook/DarkReign'', which details Osborn's tenure as the leader of the DarkerAndEdgier [=SHIELD=] called [=HAMMER=], during which time he sets up and leads his own EvilCounterpart to ''ComicBook/TheAvengers'' (as well as the ComicBook/XMen and a couple of others), dressing up psychotic supervillains to disguise themselves as the heroes, whilst pursuing an agressive domestic and foreign policy and consolidating his power by allying with major players like Loki, Namor, Emma Frost and Doctor Doom ([[MyFriendsAndZoidberg and the Hood]]), whilst once again starting to descend back into Goblin-related madness. WordOfGod is this was not an "event" like the previous examples but it did lead to many mini-crossovers as pretty much every Earth-bound hero found themselves in conflict with the maniac plus it ticks most of the boxes anyway (save that its longer), and its worth mentioning because the conclusion to it was...
** And finally in 2010, we have ''Comicbook/{{Siege}}''. [[ComicBook/TheMightyThor Thor]] had previously moved Asgard to Earth, and Osborn and Loki aren't happy (Osborn because it's foreign territory on US soil, Loki because Asgard isn't in its own realm where it belongs). So Loki convinces Osborn it would be a ''wonderful'' idea to take his army and ''attack gods''. Naturally, Thor and everyone connected with the Avengers goes ''"OhNoYouDidnt!"'' and goes to kick his ass. But the real problem wound up being [[spoiler:the Sentry: immeasurably powerful, mentally unstable (to put it mildly), and Osborn's no longer holding his leash.]] In the end, Osborn is ousted and the resurrected Steve Rogers (no longer ComicBook/CaptainAmerica) takes his place, beginning "The Heroic Age" by ending Superhuman Registration, formally reuniting the fractured Avengers teams, and bringing the Big Three (himself, Thor, and Iron Man) together on the same side for the first time since before ''Avengers Disassembled''.
* Alongside that grand arc, Marvel also released Crisis Crossovers for its cosmic properties (i.e. alien races and space-borne heroes who can't be expected to care about the political squabbles on Earth):
** The first one came in 2006 during the ''Civil War'', titled ''ComicBook/{{Annihilation}}''. It featured Annihilus, ruler of the Negative Zone, making a grand and destructive invasion into the regular universe that left a great deal of heroes dead, utterly destroyed the Nova Corps, dealt a harsh blow to the Kree Empire, and utterly shattered the Skrull Empire, going so far as to destroy the Skrull homeworld (which motivated the Skrull race to activate their sleeper cells in the above ''Secret Invasion'' to conquer Earth as a new homeworld). Ronan the Accuser was forced to MercyKill the Kree Supreme Intelligence to temporarily stave off the collapse of their empire. It took the power of Galactus himself, in an all-consuming rage, to end the threat of Annihilus.
** ''Annihilation'' got a sequel in 2007 titled ''Annihilation: Conquest'', in which Ultron, leading a vast army of robot warriors, takes advantage of the weakened and confused state of the Kree Empire to attempt to conquer it. He doesn't succeed, but he makes a very good try of it and drives the Kree further into isolation and general impotence.
** While not directly related, this is now being followed in 2009 by ''ComicBook/WarOfKings''. Part-way spun out from ''Secret Invasion'', one of the people replaced by a Skrull was Black Bolt, leader of the Inhumans. In response, the Inhumans decide they can't live in hiding any more, so their giant city on the moon blasts off for outer space, and after picking off several leftover Skrulls they conquer the remains of the Kree Empire, who created them in the first place. This sets up a war between the Kree Empire and the Shi'ar Empire, itself now under the heel of the psychopathic ''ComicBook/XMen'' villain Vulcan, with the Nova Corps, the Starjammers and the Guardians of the Galaxy caught in the middle.
** 2010 finishes with ''ComicBook/TheThanosImperative''. A superweapon detonated at the end of the war has opened a rift in space known as the Fault. On the other side is a parallel universe that has been taken over by {{Eldritch Abomination}}s (called the "Cancerverse", after how the monsters spread and corrupt). The heroes will have to join forces with Thanos, who had [[DeathSeeker been granted the death he wished]] in ''Annihilation'' and was resurrected against his will in order to fight a universe where life has won over death.

* The New 10's brought a regular rotation of Crossovers, often coinciding with promotions for Marvel movies:
** Starting in 2010 and continuing [[ScheduleSlip into 2012]], ''ComicBook/TheChildrensCrusade'' brought the Young Avengers, the Avengers, and the X-Men together to hunt down Wanda Maximoff. The Young Avengers sought to return her to the Marvel Universe, the Avengers generally wanted to contain her power, and the X-Men were out for blood after the Mutant Decimation. Wanda was found and all was forgiven after a long TheReasonYouSuck speech pointing out the hypocrisy of the Avengers and X-Men. Other important events being Victor von Doom revealing he was responsible for Wanda's descent into madness, Iron Lad undergoing his FaceHeelTurn into Kang the Conqueror, ComicBook/CassieLang dying at the hands of Victor von Doom and [[StuffedIntoTheFridge spurring said Heel Turn]], and ComicBook/{{Hulkling}} proposing to his boyfriend ComicBook/{{Wiccan}}.
** The big crossover of 2011 was ''Comicbook/FearItself''. While the world is in a state of underlying fear and paranoia (from events both in-universe and in the real world), the Red Skull (II aka Sin, daughter of the original) frees a Norse god that scares even Odin called the Serpent. The Serpent then summons hammers that turn selected superhumans into his followers "the Worthy", causing the powder keg of fear to explode among the people.
** 2011 had a smaller example in the form of ''ComicBook/SpiderIsland'' which saw everyone in New York receive spider powers. While this would normally be a BatFamilyCrossover or just a regular storyline in ''Amazing Franchise/SpiderMan'', a multitude of tie in mini series and one shots focusing on everyone from the Avengers to the Kung Fu heroes as well as tie-in issues running in the monthly titles of both ''Venom'' and ''ComicBook/TheIncredibleHercules''.
** 2012 brought ''ComicBook/AvengersVsXMen'', where the Phoenix Force is returning to Earth and has chosen Hope Summers as its new avatar, leading the two major {{Super Team}}s of the MarvelUniverse to clash over whether this will mean the resurgence of mutantkind (for the X-Men) or the destruction of humans and mutants alike (for the Avengers). Epic ConflictBall ensues. The series ended with Comicbook/{{Cyclops}}, Emma Frost, Magik and Colossus becoming fugitives, Professor X dead at Cyclops' hands, and Captain America formed the [[Comicbook/UncannyAvengers Avengers Unity Squad]] to keep something like ''AVX'' from ever happening again.
** Spring of 2013 brought ''Comicbook/AgeOfUltron'', resurrecting Ultron after his cosmic hijinks and the end of humanity with it. Interestingly, the storyline already starts off with Ultron succeeding in taking over the Earth, with the surviving heroes attempting to mount a resistance to stop the robotic villain's rule. Then it quickly turns into TimeyWimeyBall nuttiness with no real impact on the other titles. Any tie-ins in other books were labeled "AU", and had no impact on their respective running storylines. The major impact came at the end of the story, with the debut of ComicBook/{{Angela|MarvelComics}}, and ComicBook/{{Galactus}} being teleported to the ComicBook/UltimateMarvel universe, setting the stage for ''ComicBook/CataclysmTheUltimatesLastStand''.
** Meanwhile, Summer in 2013 brought ''Comicbook/{{Infinity}}''. Building off a storyline from ''Comicbook/TheAvengers'' main book, it centers around heroes dealing with two major cosmic threats, one a new cosmic enemy called the Builders and the other ComicBook/{{Thanos}} leading a new invasion army, hitting the planet Earth at nearly the same time. Despite the name and use of Thanos, WordOfGod says that the event is not intended to be a sequel to the similarly named ''ComicBook/TheInfinityGauntlet'' and its sequels.
** 2014 kicked off with ''ComicBook/OriginalSin'' by Jason Aaron and Mike Deodato Jr. It is a murder mystery about the killing of Uatu the Watcher and the heroes' buried secrets which he has personally witnessed but kept to himself being leaked out to the superhero community. (It's highly reminiscent of DC's ''ComicBook/IdentityCrisis.'') The culprit was [[PutOnABus exiled to the moon]], forced to watch the Earth as Utatu once did for their troubles.
** Fall of 2014 brought ''ComicBook/{{AXIS}}'' by Rick Remender. Spinning out of the events of ''Comicbook/UncannyAvengers'', the threat of the Red Skull takes on new heights as his new powers begin to turning the lives of Comicbook/TheAvengers, the Comicbook/XMen and even several noteworthy Marvel villains upside down in his bid for domination. ComicBook/CassieLang and Brother Voodoo are returned to the world of the living during this event.
** In 2015 there was only one headline event: a new ''[[ComicBook/SecretWars2015 Secret Wars]]'' by Jonathan Hickman, where the entire Marvel Multiverse was destroyed and a new Battleworld created from their shards. An "All-New" universe took the place of the old one after the series ended. Ultimate Marvel fan favorites like ComicBook/MilesMorales were merged into the primary Marvel Universe while the rest of the Ultimate Universe was [[{{cancellation}} completely destroyed]].
** In early 2016, ''ComicBook/AvengersStandoff'' was launched and the Marvel heroes discovered a S.H.I.E.L.D. facility that used a living Cosmic Cube named Kobik to rehabilitate super villains. Rehabilitation in this case is a polite way to say "brainwash into living peacefully in a false suburbia prison." The prisoners woke up to go on a RoaringRampageOfRevenge while the heroes tried to contain the damage. The fallout from ''Standoff'' left most of the Marvel U with a heavy distaste for S.H.I.E.L.D. and central authority in general, and Steve Rogers is mind-wiped into being a [[FaceHeelTurn sleeper Hydra Agent]].
** Next in 2016 we had ''ComicBook/CivilWarII'' in which the superhero community was split in half ''again'', this time over a PrecrimeArrest moral debate when an Inhuman named Ulysses begins suffering accurate visions that make Nostradamus look like an amateur, and ''ComicBook/InhumansVsXMen'' in which the [[ExactlyWhatItSaysOnTheTin Inhumans fight the X-Men.]] Carol Danvers leads the pro-Precrime faction with the Inhumans while Tony Stark leads the anti-Precrime faction. Ultimately, Tony was left in a coma and [[ComicBook/{{Ironheart}} Riri Williams assumed his mantle as Ironheart]], Carol Danvers was able to institute more powers and reforms for herself and S.H.I.E.L.D., a global space shield was erected to protect Earth from cosmic threats, and the Inhuman Ulysses ascends to join the Watchers and remove his prophecy powers from the material world. [[LockedOutOfTheFight Which comes in handy for Cap's plans]] in...
** ''ComicBook/SecretEmpire'' by Nick Spencer was 2017's primary Crossover, in which the Steve Rogers Captain America, who has [[FaceHeelTurn become an agent of Hydra]] unbeknownst to the rest of the Marvel Universe, has taken over as head of S.H.I.E.L.D. as he begins his [[DayOfTheJackboot putting his bigger plan of taking over the country into motion]], forcing the rest of the Marvel Heroes to band together to stop him. Carol Danvers was locked out of the Earth by her own space shield and the Cosmic Heroes (along with anyone who had a shot at kicking Hydra Cap's ass) was forced to fight an endless armada of Chitauri in space until the war's end. Hydra Cap was ultimately stopped and normal-Cap remade from the shards of the Cosmic Cube.
** A smaller Crisis Crossover took place with ''ComicBook/MonstersUnleashed'', a mini-series that forced the heroes of the world to band together against a seemingly never-ending onslaught of colossal monsters from space known as Leviathons. It also serves as the OriginStory for Kei Kawade, who later takes up the hero name of "Kid Kaiju".
** 2018 had ''ComicBook/InfinityCountdown'' leading to ''ComicBook/InfinityWars2018'', where the the Infinity Stones reappeared and ComicBook/DoctorStrange gathered up the Stone holders in preparation against a mysterious being known as Requiem, who seeks the Stones.
** 2019 debuted ''ComicBook/WarOfTheRealms'', Malekith and his army, having taken nine of the Ten Realms, now comes for the final realm: Earth. [[ComicBook/TheMightyThor Thor]] must now prepare everyone in defense of Earth and the war to come. After the dust settled, Odin abdicates as King of Asgard in favor of Thor, Jane Foster joins the Valkyries as ''the'' Valkyrie, and Loki begins to establish a realm of his own among the Frost Giants.
** 2020's crossover event was ''ComicBook/{{Empyre}}''. Hulkling embraced his dual royal bloodlines and leads a unified Kree-Skrull Empire to war against the Cotati, a plant-like species preparing to launch a genocidal crusade against all "animals" in the galaxy. During the event, Hulkling becomes a true Emperor instead of his initial status as a figurehead, the Kree/Skrull War comes to an end under his rule, the Cotati are exiled to a garden world in an unknown region of space with no power to pursue vengeance, and Abigail Brand falls out with Captain Marvel over her running of Alpha Flight and failure to consult with the team about policy regarding the Cotati at the very beginning of the war. Also, Hulkling and Wiccan ''finally'' get married.
* In the same vein, the ''VideoGame/MarvelUltimateAlliance'' video game has the heroes banding together to stop villains under Dr. Doom and Loki from pulling off an EvilPlan [[spoiler:that would allow Doom to steal the power of a god from Odin]]. The sequel is an adaptation of the ''Secret War'' and ''Civil War'', minus the second half of ''Civil War'' as the game diverges at the end of the third issue of that storyline for a different, original ending where the heroes must band together to stop [[spoiler:one of Mr. Fantastic's pro-reg scientific plans gone out of control from dooming humanity's freedom]].
* ComicBook/UltimateMarvel had one with ''ComicBook/{{Ultimatum}}'', meant to be the last title in the Ultimate Universe before it got relaunched as Ultimate Comics in 2009. The plot involves Magneto plotting revenge on the Ultimates for the murder of the Scarlet Witch, [[KillEmAll killing absolutely everybody in the process]].
** In 2011, Ultimate Marvel had ''[[TonightSomeoneDies The Death of Spider-Man]]'' where, well, [[ExactlyWhatItSaysOnTheTin Spider-Man died]]. It ran through ''ComicBook/UltimateSpiderMan'' and ''[[ComicBook/TheUltimates Avengers vs. New Ultimates]]'', but is something of an odd case as thus far the series have only intersected once (Spidey got injured in an Avengers/Ultimates fight) and have since remained separate, but it serves as an explanation as to why Spider-Man has to fight the Sinister Six with no back-up beyond an ill-prepared Iceman and Human Torch. Nonetheless, it prompted a second linewide relaunch.
** In 2012, Ultimate Marvel had ''Divided We Fall/United We Stand'' which involved all three ongoing titles at the time - Ultimate Comics Spider-Man, Ultimates and X-Men - dealing with a fractured United States. [[spoiler: It notably culminated with Captain America being voted in as President of the United States.]]
** In 2013, the Ultimate line had ''Comicbook/CataclysmTheUltimatesLastStand'', which deals with the aftermath of ''Age Of Ultron'' with the Ultimate heroes banding together to fight off Galactus.

[[folder:Other Comic Books]]
* ''Fire From Heaven'' was a 1996 Creator/ImageComics crossover with ''Backlash'', ''Deathblow'', ''[[ComicBook/Gen13 Gen¹³]]'', ''Sigma'', ''ComicBook/{{Stormwatch}}'', ''Wetworks'', and ''ComicBook/WildCATS''. Publishing delays lead to a confusing plot and reading order.
* Of bizarre note is the ''ComicBook/JLAAvengers'' crossover that happened around 2004ish.
** Although these cross-company crossovers usually end up either being non-canon or forgotten, this one actually led to some small changes: the universe of the Crime Syndicate of Amerika (an evil JLA) was rebooted as a result of the defeat of Krona (who had, destroyed that entire universe in the prologue). This led to vague (and therefore non-copyright breaking) references to the events of the crossover the next time that the JLA met the CSA. Some people also say that the events of ''House of M'' may also have stemmed from the events of ''JLA/Avengers'' as well, since the Scarlet Witch started to lose her sense of reality and judgment after tapping into the chaotic (read: evil) chaos magic of the DCU. This is just {{Fanon}}, but it's too cool a possibility not to mention.
** Marvel has officially accepted ''JLA/Avengers'' as canon, since references to it are made in the Marvel Universe Handbooks, without actually naming the DC characters, of course.
** The actual crossover itself was integrated fully (as in, no denying it anymore) into DC continuity with the release of ''Trinity'' #7, with the Avengers being referred to as the "Others"; you can even see what seems to be a silhouette of ComicBook/CaptainAmerica in one panel (though it's just as believable to think that was Franchise/TheFlash - it's left rather vague). Krona's fate at the end of the crossover also played a part in a few ''JLA'' stories after.
* And as long as we're being complete, there was the ComicBook/MarvelVersusDC / ComicBook/AmalgamUniverse story, in which both the Marvel and the DC multiverses face annihilation -- and so the two multiverses were forcibly merged for a short time to keep their worlds alive. (Amalgam Dark Claw = DC Franchise/{{Batman}} + Marvel ComicBook/{{Wolverine}}; Amalgam Super Soldier = DC Franchise/{{Superman}} + Marvel ComicBook/CaptainAmerica; Amalgam Amazon = DC Franchise/WonderWoman + Marvel ComicBook/{{Storm}}; Amalgam Lobo The Duck = DC Lobo + Marvel Comicbook/HowardTheDuck; Amalgam Captain Marvel = DC [[ComicBook/{{Shazam}} Captain Marvel]] + Marvel ComicBook/CaptainMarVell; et multiple cetera.)
* Disney did more than one.
** The first one is probably ''La Storia Infinita'', a transposition of the basic plot of ''Literature/TheNeverendingStory''[[note]]It was never printed in English, but [[KeepCirculatingTheTapes rumor has it you can find it]] on [[www.neverendingstorydisney.jimdo.com this website]] with the password [[spoiler: Scanlation]][[/note]][[note]]The website no longer works, but go [[https://issuu.com/thomas.grazia/docs/topolino_1883_-_paperino_in_la_storia_infinita_ here]] if you want to check out the coomic anyway.[[/note]]. The story opens by an emergency meeting of all the heroes in the Disney universe (and we do mean all: not just from the comics, but also from the movies, including the more obscure ones) to try to solve the threat of the Nothing, a [[EldritchAbomination maybe-sentient cosmic force]] that is absorbing the whole universe and replacing it with blank, featureless [[ExactlyWhatItSaysOnTheTin nothingness]]. WesternAnimation/MickeyMouse [[TheChosenOne is chosen]] to look for a solution, and, after getting help from [[WesternAnimation/TheSwordInTheStone Merlin]] and WesternAnimation/{{Dumbo}}, finds out that Donald is the ''real'' [[TheChosenOne Chosen One]]. On the way, they fight various Franchise/DisneyVillains led by Maleficent. However, this story differs from traditional Crisis Crossovers in that the hundreds of summoned crossover heroes do very little, since Mickey, Donald, and ''maybe'' Dumbo are doing most of the adventuring and the others are just hanging around in the Castle the whole time; it was also a self-contained two-part story arc, rather than spanning several titles.
** ''ComicBook/TheLegendOfTheChaosGod'' is a multi-episode crossover between one and every show of ''WesternAnimation/TheDisneyAfternoon'' that was part of the Disney Duck and Mice comic universe. That includes ''WesternAnimation/DuckTales1987'', ''WesternAnimation/DarkwingDuck'', ''WesternAnimation/TaleSpin'', ''WesternAnimation/GoofTroop'' and ''WesternAnimation/ChipNDaleRescueRangers'', who were all battling against the vile sorcerer Solego.
** The New Year celebration of year 2000 was the setting for the ''Millenium Orbs'' saga, featuring a crossover between the [[ComicBook/MickeyMouseComicUniverse Mice]] and [[ComicBook/DisneyDucksComicUniverse Duck comic universes]], all battling against evil wizard Euclidus.[[note]]The story was only printed in English in 2007, so the references to the year 2000 were dropped, with Euclidus's backstory moved from 1000 A.C. to the year 1707. The stories generally suffered from it.[[/note]]
* The ''Zodiac Stone'' series does a similar thing, with Ducks and Mice both travelling the world to look for [[GottaCatchThemAll the pieces of the Zodiac Stone, a mythical artifact that can predict the future]], and stopping the Phantom Blot (assisted by Pete and the Beagle Boys) from getting it first. The scope of the "crisis" is not actually much higher than usual Disney comic adventures, but it was nevertheless advertised as one.
** In 2011, Boom! Comics was losing the license to WesternAnimation/TheDisneyAfternoon comics, so they went out with a bang. As such, ''ComicBook/DarkwingDuck'' and ''ComicBook/DuckTales'' are crossed over for the last arc of the respective series, with various villains led by the Phantom Blot (from the ''Mickey Mouse'' comics, though the mouse himself doesn't appear) who himself [[spoiler: mind-controlled by Magica De Spell]].
* Subversion: New England Comics ran a ''Crisis on Finite [[ComicBook/TheTick Tick]] Crossovers'', which featured all 3 titles in the [[Franchise/TheTick Tickverse]]. The editors explained that having only 3 comics severely limited the number of money-making crossovers they could do.
* Parodied in ''ComicBook/TopTen'', where a character has an Ultra-Mouse infestation in his mother's apartment. So, he hires the EX-VERMINATOR, who releases Atom Cats to deal with them, but with so many super-powered creatures in such a confined space, it turned into a "Whole Secret Crisis-War Crossover Thing" which eventually [[CosmicRetcon rewrote the timeline]] so the Ultra-Mouse infestation never happened, and nobody even remembers it -- except the EX-VERMINATOR, [[ShaggyDogStory who is thus pissed nobody will pay him]].
* Though ''ComicBook/AstroCity'' is the only series in its continuity and thus incapable of crossovers, they still managed to play with this one.
** In "The Nearness of You", a man becomes increasingly obsessed about a woman who keeps appearing in his dreams. It turns out it's because a minor villain caused a TemporalParadox that threatened the universe and required all of the heroes to stop it -- and the woman is his wife who [[RetGone ceased to exist]] in the repaired timestream. Yes, the Crisis Crossover is relegated to a ''background reference.''
** Also appears in the ending of the "Confession" arc, which is basically a Crisis Crossover as seen from the sidelines. The event in question is a worldwide alien invasion with dozens of heroes against an army of shape-shifting extraterrestrials, yet there's only a dozen panels devoted to the actual battles themselves.
* Creator/ValiantComics:
** The "Unity" Crossover early in its history, in which the 41st century heroes and the 20th century heroes had to join come together to face a woman with the power to destroy all history.
** They also did a crossover with Creator/ImageComics called ''ComicBook/{{Deathmate}}''.
* ''When Bongos Collide'' was a crossover of Bongo Comics, which publish comics based on ''ComicBook/TheSimpsons''. It included ''Itchy & Scratchy'' #3, ''The Simpsons'' #5, and ''Bartman'' #3. It can be read in ''Bartman: The Best of the Best'' collection. Also, there were two series of ''Simpsons[=/=]WesternAnimation/{{Futurama}}'' crossover comics -- which reaffirm the MutuallyFictional nature of the two shows in the other's universe (though the crossovers take place in the ''Futurama'' universe, because it'd be easier to use its sci-fi nature to use the TrappedInTVLand and RefugeeFromTVLand plots to allow the meetings).
* In 2008, the Franchise/StarWarsExpandedUniverse got in on the act with ''Vector'', which told a single story starting in ''VideoGame/KnightsOfTheOldRepublic'', then moving in chronological order through Dark Horse's four ''Franchise/StarWars'' titles, before ending in a WhamEpisode in ''ComicBook/{{Legacy}}''. And it was really good, too.
** ''Legacy'' also crossed the prequel era with Tatooine's Sand People and the NJO era.
* The now-defunct EclipseComics got into the act with ''Total Eclipse'', written by Marv Wolfman. The story involved a villain named Zzed[sic], who was born many millenia ago during an event called the Total Eclipse (all the planets and moons of the Solar System aligned with thousands of planets, moons and stars across the galaxy). As a result, he has been [[WhoWantsToLiveForever cursed with immortality]], and seeks only his own death, which he can only achieve by destroying all creation. [[OmnicidalManiac He has no problem with that at first.]] Unique in being the only Crisis Crossover to feature appearances by ComicBook/MiracleMan, ComicBook/{{Airboy}}, ComicBook/MsTree and Beanish of ''ComicBook/TalesOfTheBeanworld''.
* The long awaited ''ComicBook/WarOfTheIndependents'' mini-series brings together creator-own characters as diverse as ''ComicBook/{{Gumby}}'', ''ComicBook/TheTick'', ''ComicBook/ScudTheDisposableAssassin'', ''ComicBook/{{Cerebus}}'', ''ComicBook/{{Shi}}'', ''ComicBook/{{Bone}}'' and ''ComicBook/HackSlash''. Some of the same characters also appeared previously in the ''ComicBook/{{Normalman}}''/''ComicBook/MegatonMan'' special, ''ComicBook/{{Gen 13}}'' ABC, and Shi / {{Cyblade}}: The Battle for Independents.
* ''Image United'', a series which brings together not only Creator/{{Image}}'s iconic characters, but also their creators to personally draw them in each appearance.
* Creator/{{Zenescope|Entertainment}} has ''The [[NamesToRunAwayFromReallyFast Dream Eater]] Saga''. A threat so major that even [[CardCarryingVillain Belinda]] and [[AxCrazy The Queen of Hearts]] are fighting against it.
* ''ComicBook/SonicTheHedgehogMegaManWorldsCollide'', a large 12-part {{crossover}} flowing through Creator/ArchieComics' three video game licenses: ''ComicBook/MegaMan'' #24-27[[note]]Parts 1, 4, 7 and 10[[/note]], ''[[ComicBook/SonicTheHedgehogArchieComics Sonic the Hedgehog]]'' #248-251[[note]]Parts 3, 6, 9 and 12[[/note]], and ''[[ComicBook/SonicTheHedgehogArchieComics Sonic Universe]]'' #51-54[[note]]Parts 2, 5, 8 and 11[[/note]]. The gist is that following the ''Sonic Genesis'' arc in the Archie Sonic comics, a Chaos Emerald has landed in the ''Mega Man'' universe, leading to a chance meeting between Doctor Wily and Doctor Eggman as they team up to cosmically conquer their universes. The ramifications are that Mega Man hits the ResetButton on his universe, pushing the crossover to at least after an hypothetical ''VideoGame/MegaMan10'' adaptation in the ''Mega Man'' universe, whereas Eggman inadvertently causes a {{cosmic retcon}}ning of Mobius on a scale the Archie Sonic comics have never faced before in its 20-year history, primarily designed in real life terms to jettison the aftermath of [[ScrewedByTheLawyers the Ken Penders legal case]] on the Sonic comics' narrative without just unceremoniously killing his characters off-screen or invoking WhatHappenedToTheMouse.
** This was later followed up on with ''ComicBook/SonicTheHedgehogMegaManWorldsUnite'', which followed up on the ramifications of the previous crossover and included ''ComicBook/SonicBoom'' and ''VideoGame/MegaManX'' as well thanks to X's arch-enemy Sigma as the instigator of the events. [[spoiler:By the third act, with Sigma in full AGodAmI mode thanks to being amped up on planetary energy, the combined heroes begin pulling characters from other worlds to help, crossing over with half a dozen franchises from Sega and Capcom each.]] In a reversal of the previous event, ''Sonic'' came out of the story with no consequences while ''Mega Man'' saw [[spoiler:Xander Payne get thrown back in time by Sigma's defeat and take TheSlowPath to become Mr. X in the present]].
* Creator/IDWPublishing had a few.
** ''Infestation'' has IDW's ''ComicBook/ZombiesVsRobots'' [[EverythingsDeaderWithZombies infecting the publisher's licensed universes]] of ''Transformers'', ''ComicBook/GhostbustersIDW'', ''G.I. Joe'' and ''Star Trek''. Its most notable impact is having Kup be PutOnABus on the ''Transformers'' corner, not coming back until ''Dark Cybertron'' below. Its sequel ''Infestation 2'' had [[Franchise/CthulhuMythos the Elder Gods]] crossing out instead, and the addition of ''ComicBook/ThirtyDaysOfNight'' and ''ComicBook/TeenageMutantNinjaTurtlesIDW'' but has no lasting repercussions on even a single series.
** ''Series/TheXFiles: Conspiracy'' had Fox Mulder and Dana Scully aiding the Lone Gunmen in their search to discover the cure for a virus, which lead them to stumble upon ''Transformers'', ''Ghostbusters'', ''ComicBook/TheCrow'' and ''TMNT''.
** ''ComicBook/TheTransformersMoreThanMeetsTheEye'' and ''ComicBook/TheTransformersRobotsInDisguise'' crossed over in ''ComicBook/DarkCybertron'', a multi-part storyline involving Shockwave launching his EvilPlan on Cybertron. The two series are set in the same universe and have intersected and referenced each other multiple times, but this was the first real crossover between the two. The battle against Shockwave notably results in Optimus Prime returning to Autobot leadership after a self-imposed exile that started said two comic series and Megatron becoming an Autobot cast member of ''More than Meets the Eye''. The event also saw the debut of franchise-recurring character Windblade.
** ''ComicBook/{{Revolution|2016}}'' marks the inauguration of the ComicBook/HasbroComicUniverse. The basic gist is that the Transformers, G.I. Joe, ComicBook/{{ROM|IDW}} and the newly-formed M.A.S.K. have a severe case of ConflictBall over mistaken intentions while the ComicBook/{{Micronauts|IDW}} head to Earth in a bid to save Microspace, then they all join forces when they realize that a VillainTeamUp has set them up.
** This was followed up by ''ComicBook/FirstStrike'' in 2017, where a cabal of Earth-based villains launches a genocidal assault on Cybertron, its leader sick and tired of the extraterrestrials conflicts the Transformer race is bringing to Earth. [[spoiler:But one of their numbers has a secret agenda of his own for Cybertron, leading to the IDW debuts of the Visionaries and Unicron.]]
** ComicBook/CartoonNetworkSuperSecretCrisisWar, an up coming 6-part Mini-Series that crosses the main characters and villains of the shows ''Dexter's Laboratory'', ''Samurai Jack'', ''The Powerpuff Girls'', ''Ben 10'', and ''Ed Edd n Eddy''. The story also branchs off into 6 One-shots featuring ''Johnny Bravo'', ''Codename: Kids Next Door'', ''Cow and Chicken'', ''Foster's Home for Imaginary Friends'', and ''The Grim Adventures of Billy and Mandy''.
* Dynamite Entertainment had "Prophecy", starring Vampirella, Red Sonja and, uhh, some additional characters nobody remembers. (Xena wasn't on the payroll. Fans still pout.)
* Dynamite later did the "Swords of Sorrow" crossover event, which was similarly based around all of their {{Stripperiffic}} ActionGirl characters allying and/or fighting due to a multiversal threat.
* Parodied in ''ComicBook/TheBoys'': the appearance of an alien battlestation in Earth orbit prompts every hero and villain to team up to take it down. In fact, the whole thing is a fake: they're all going to a tropical island for a few days of [[VillainWithGoodPublicity entirely undeserved]] booze, sex, drugs, and generalized hedonism, known as Herogasm.
* ''ComicBook/DoctorWhoTitan'' has yearly Crisis Crossover events featuring all the Doctors with regular titles, plus cameos by some others. So far, there have been ''ComicBook/DoctorWhoFourDoctors'', ''ComicBook/DoctorWhoSupremacyOfTheCybermen'', and ''ComicBook/DoctorWhoTheLostDimension''. The first two were published as stand-alone miniseries, but the third was published as a traditional superhero-comic crossover event taking over an issue of each of the regular series. (Possibly because the two miniseries had suffered embarassing ScheduleSlip.)
* The Franchise/{{Transformers}} multiverse has a Crisis of sorts, called the Shroud (or Shrouding). Which results in altering the fabric of reality that strengthened the boundaries between universes from that point on. A major result being the splintering of the multiversal singularities into infinite variations of themselves throughout the multiverse.
* Starting in May 2019, Terry Moore's ''Five Years'' is a crossover set in the [[TheVerse Terryverse]], in which the casts of ''ComicBook/StrangersInParadise'', ''ComicBook/{{Echo}}'', ''ComicBook/RachelRising'' and ''Motor Girl'' deal with the threat of the Phi Bomb, a super-weapon that a group of defense experts are scheduled to complete in [[TitleDrop five years]]. The Phi Bomb is designed to destroy all hydrogen atoms in a target area. Once it's tested, according to information that Katchoo, Tambi and Rachel uncovered, the uncontrolled explosion will spread out to destroy all hydrogen. [[ApocalypseHow Everywhere in the universe.]]

[[folder:Advertising]]
* The combined forces of KFC, Taco Bell, and Pizza Hut join forces to Defeat the Dark Side [[https://www.youtube.com/watch?v=BnbNXlpWdh8 in these commercials]], done to promote ''Film/ThePhantomMenace''.

[[folder:Anime and Manga]]
* The ''Franchise/PrettyCure'' MagicalGirl metaseries have their own Crisis Crossover movie series labeled "Pretty Cure All Stars", featuring heroines from all series released until then.
** However, after quite a few All Star movies and too many heroes to work with, the franchise's Crisis Crossover movie series may be going in a new direction with its upcoming film, "Pretty Cure Dream Stars;" which feature only two Precure teams teaming up and possibly meeting a member of a new team.
** Then a canonical crossover happened in ''Anime/HugttoPrettyCure'' when one of the villains froze time and all the Cures had to stop him.
* The 2nd part of the ''Anime/TimeBokan'' OVA in 1993 involves the Dorombo Gang from ''Anime/{{Yatterman}}'' invading a city populated by other Creator/TatsunokoProduction characters, and who should show to stop them but the Anime/ScienceNinjaTeamGatchaman, Casshern, Hurricane Polymar, and Tekkaman?
* ''Manga/TsubasaReservoirChronicle'' features characters, SpinOffspring, {{Expy}}s, and/or cameos from more or less everything Creator/{{CLAMP}} has ever written.
* The ''Majokko Club Yoningumi A-kūkan kara no Alien X'' OVA is a crossover between Creator/StudioPierrot's most successful MagicalGirl series. [[Anime/MagicalAngelCreamyMami Creamy Mami]], [[Anime/MagicalStarMagicalEmi Magical Emi]], [[Anime/MagicalIdolPastelYumi Pastel Yumi]], and [[Anime/PersiaTheMagicFairy Persia]] all team up to fight alien forces on the moon.
* ''Anime/DigimonXrosWarsTheYoungHuntersWhoLeaptThroughTime'' has one in its final few episodes, which saw the return of all the leaders and various other members of all previous Digimon teams.
* ''Anime/YuGiOhBondsBeyondTime'' is one between the protagonists of the first three series. It's spawned a fair few fanfiction imitations as well.
* Invoked in-universe in ''Anime/ReCreators'', where in order to empower the [[RefugeeFromTVLand Creations]] against [[BigBad Altair]], the government formulates a plan to have their creators make a crossover event film in which the characters join forces to defeat Altair due to the fact that the Creations' power-ups rely on the [[ClapYourHandsIfYouBelieve general public to accept and embrace them]].

[[folder:Fan Works]]
* ''FanFic/CapForce'' is basically a Creator/{{Capcom}} version of Marvel's Infinity War story. A mysterious and powerful entity has caused most of the Capcom multiverse to become dust which nearly caused TheEndOfTheWorldAsWeKnowIt. Heroes from most of Capcom's franchises (Street Fighter, Darkstalkers, Mega Man X, Resident Evil, Devil May Cry, Final Fight, Phoenix Wright: Ace Attorney, Dead Rising, Power Stone, Rival Schools, Captain Commando, Okami, etc.) are brought together to combat this threat and hopefully undo the damage done to the multiverse.
* ''FanFic/Hottie3TheBestFanFicInTheWorld'' and its sequels "Hottie 4: Even Better Sequel" and "Hottie 5: Fifty Shades of Epic".
* ''VideoGame/MushroomKingdomFusion'' takes over a dozen video game mascots and puts them all into a single game.
* ''[[FanFic/SonicGenerationsFriendshipIsTimeless Sonic Generations: Friendship is Timeless]]'': Chapter 1 has the [[EldritchAbomination Time Eater]] attacking both [[VideoGame/SonicGenerations Sonic's world]] and [[WesternAnimation/MyLittlePonyFriendshipIsMagic Equestria]], sending the characters through different moments of Sonic's past. The ponies must now work together with Sonic's friends to save both of their worlds.
* The ''FanFic/PonyPOVSeries'' plays with this -- all four generations of ''MyLittlePony'' existed in the same timeline at different points [[spoiler: (until the Alicorns and Draconequi [[CosmicRetcon erased]] G3 to prevent [[TheEndOfTheWorldAsWeKnowIt universal collapse]])]], but they never actually meet up. [[spoiler: Until the FinalBattle of the [[BadFuture Dark World]] timeline, when Twilight uses her connection with Minty Pie and the {{temporal paradox}}es created by [[GreaterScopeVillain Nightmare Eclipse]]'s GroundhogDayLoop plan to [[GondorCallsForAid summon]] the G1, G2, G3 and G4 (pre-Reign of Chaos) mane casts in order to use multiple sets of the Elements of Harmony to defeat Eclipse and her {{Psycho Ranger|s}} CoDragons.]]
* This ''Series/{{Victorious}}'' fanfic [[https://www.fanfiction.net/s/11623257/1/Victorious-War-of-Two-Realms crossover]] wherein an united alliance, led by Maleficent, resurrects the three Ice Barrier Dragons (Brionac, Gungnir, and Trishula), all from ''TabletopGame/{{YuGiOh}}'', to attack numerous dimensions, and only the Chosen Ones (the actual Victorious gang), can stop them. Characters range from ''Franchise/{{Disney Animated Canon}}'', ''Film/{{Descendants}}'', ''WesternAnimation/WinxClub'', ''WesternAnimation/GravityFalls'', ''WesternAnimation/KungFuPanda'', ''WesternAnimation/PhineasAndFerb'', ''WesternAnimation/AdventureTime'', and ''WesternAnimation/TheFairlyOddparents''.
* In this fanfic [[http://www.fanfiction.net/s/7382184/1/Phineas-and-Ferb-Attack-from-other-Dimensions crossover]] sequel to ''WesternAnimation/PhineasAndFerbTheMovieAcrossThe2ndDimension'' have the characters of Phineas and Ferb teaming up with characters from other franchises. such as ''WesternAnimation/MyLittlePonyFriendshipIsMagic'', ''WesternAnimation/SpongeBobSquarePants'', ''VideoGame/SonicTheHedgehog'', ''Franchise/MarvelUniverse'' and among others. for stop Dr. Heinz Doofenshmirtz, Plankton and villians from other universes from taking over the multiverse
* This [[http://www.fanfiction.net/s/7878969/1/The-Transformers-Marvel-Continuty fanfic]] is a shared universe for the Transformers and Marvel characters. while no official crossover have been written, Crisis Crossover stories are set to be written for conclude the Second and Third Phases of this fanfic.
* ''[[http://www.fimfiction.net/story/165235/multiversal-harmony Multiversal Harmony]]'' is a rather unique example. It's a MassiveMultiplayerCrossover of the universes of six different ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' {{Alternate Universe Fic}}s -- [[Fanfic/RainbowDoubleDashsLunaverse The Lunaverse]], [[Fanfic/RainboomsAndRoyalty The Dashverse]], [[Fanfic/TheElementsOfHarmonyAndTheSaviorOfWorlds The Hasbroverse]], [[Fanfic/LifeInManehattan The Manehattenverse]], Fanfic/TheCadanceverse, and [[Fanfic/BedHeadsFlipverse The Flipverse]] -- in which the different Elements of Harmony from those universes are brought together on an adventure together.
* ''Fanfic/TheEquestrianWindMage'' is a crossover between ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' and ''Franchise/TheLegendOfZelda'' that increases in scope as the villains of Hyrule take notice of Equestria. This culminates in Season 3, when a permanent portal opens between both worlds, and [[GodOfEvil Majora]] launches simultaneous attacks on them.
* ''Fanfic/YuGiOhDissidia'' is a fairly blatant example given that it's ExactlyWhatItSaysOnTheTin, being a crossover between its respective spin-offs. There are actually several fanfics like this, often done in the spirit of the Official crossover (see above).
* ''Fanfic/BeatTheDrumsOfWar'' brings together every ''Fanfic/{{Bait and Switch|STO}}'' OriginalCharacter crew to date for the beginning of all-out war between TheAlliance and the Iconians. The story is mainly told from the perspectives of Kanril Eleya and D'trel, with cameo appearances by Brokosh and Morgan t'Thavrau.
* ''FanFic/BringMeToLife'' features both [[Series/BuffyTheVampireSlayer the Scooby Gang]] and [[Series/{{Angel}} Angel Investigations]] teaming up to fight Jasmine and the [[UltimateEvil First Evil]].
* ''FanFic/ShatteredSkiesTheMorningLights'' brings together the [[MagicalGirl Magical Girls]] of ''Franchise/SailorMoon'', ''Manga/CardcaptorSakura'', ''Franchise/PrettyCure'', ''Franchise/LyricalNanoha'', and ''Franchise/PuellaMagiMadokaMagica'' to save reality.
* ''FanFic/MegaManStarNetwork'' brings together ''VideoGame/MegaManBattleNetwork'' and ''VideoGame/MegaManStarForce''. As Cain and Hyde team up and form an evil time travelling organization. Starting with Cyber City and Wilshire Hills switching places.
* The ''Fanfic/HoursVerse'' brings together ''VideoGame/Persona3'', ''VideoGame/Persona4'' and ''VideoGame/Persona5'', while also occasionally featuring characters from ''VideoGame/{{Persona|1}}'' and ''VideoGame/Persona2''.
* [[https://www.fanfiction.net/s/13031616/1/The-Ultimate-Crossover-Crisis-Brawl The Ultimate Crossover Crisis Brawl]] is a crossover story that features characters from TV shows, video games and webcomics uniting for a stand after their worlds are attacked and wiped out one by one by a BigBad with a personal grudge and an unknown motivation. Together, the [[LoadsAndLoadsOfCharacters big cast]] which contains characters from ''Series/KeepingUpAppearances, ''Series/MyNameIsEarl'', ''WebComic/DeerMe'', ''VideoGame/NightInTheWoods'', ''Series/{{Seinfeld}}'', ''WebComic/{{Digger}}'' and many more planned out for the future fight not just to save and restore one world, but all worlds.
* ''Franchise/PowerRangers'':
** "[[https://www.fanfiction.net/s/2207501/1/Restless-Warriors Restless Warriors]]" initially features Maya, Kelsey, Taylor, Dustin and Kira joining forces to oppose a demon invasion based on visions Maya has received from Trini's spirit and a prophecy in the Ninja Scrolls, but Eric, Tori and Conner soon join the group due to their bonds with Taylor, Dustin and Kira respectively, and the final battle [[spoiler:brings in the other Yellow Rangers, from Aisha to Z]].
** While ''Fanfic/CrimsonRising'' focuses on Hunter Bradley learning his true history, all available Rangers up to ''Series/PowerRangersOperationOverdrive'' join forces to oppose Ivan Ooze's latest invasion and his new villain army, even when some of them are rendered powerless and reduced to a 'support role'.
* Referenced in an omake of the ''Fanfic/PokemonResetBloodlines'' sidestory "Gligarman Interlude". The titular hero is giving a lesson to the Night Watchers (a trio of Bloodliner superheroes), when suddenly, a portal opens up and out comes a being called [[WesternAnimation/ThomasAndFriends Thomas T.H. Humba]] who tells them the universe has entered a period of crisis, and heroes are being recruited to save it, so the four of them immediately accept and go through the portal. The omake ends prompting the readers to check several essential comic book issues, including Blaziken Mask, Gligirl, The Black Arachnid, the Mighty Accelguard, among others.
* ''Fanfic/InfinityCrisis'' is a crossover between the Franchise/MarvelCinematicUniverse and the Series/{{Arrowverse}} where Thanos' use of the Infinity Stones dusts half the population of the entire multiverse, forcing Team Arrow, Team Flash, the Legends of Tomorrow, and Supergirl to team up with the Avengers to figure out a way to restore the balance. The sequels and spinoffs add even more into the fray, including ''Series/TheOrville'', ''Series/Merlin2008'', the Franchise/DCExtendedUniverse, ''Series/DoctorWho'', and the most popular cartoon series of the 1980s.
* In ''Fanfic/AnotherRainbowInAnotherSky'', it's mentioned that there's a civil war between the Dream Valley (G1), Friendship Gardens (G2), and Ponyville (G3) ponies.

[[folder:Film — Live-Action]]
* ''[[Creator/SeltzerAndFriedberg Disaster Movie]]'' can be seen as this, with various movies crossing over as the end of the world occurs.
** Can also be applied to ''Film/ScaryMovie'' and its sequels.
** It seems that mashup parody movies is becoming a genre on itself.
* ''Franchise/MarvelCinematicUniverse:''
** ''Film/TheAvengers2012'' is a crisis crossover for all [[Franchise/MarvelCinematicUniverse Marvel Studios movies]] starting with 2008's ''Film/IronMan1''. However, this was the plan from the very start, as it was first set up in TheStinger of ''Iron Man'' and just building with each new film released in the next three years.
** ''Film/AvengersAgeOfUltron'' reunites the team in reaction to events laid out in the intervening films, as well as being influenced by events in ''Series/AgentsOfSHIELD'' (though the Agents of S.H.I.E.L.D. don't appear).
** ''Film/CaptainAmericaCivilWar'' crosses over the cast of the ''Captain America'' movies with the cast of the ''Avengers'' movies (sans [[ComicBook/TheMightyThor Thor]] and Comicbook/TheIncredibleHulk), as well as unaffiliated heroes Comicbook/BlackPanther, Film/AntMan1, and Franchise/SpiderMan.
** ''Film/AvengersInfinityWar'' once again ties together various sub-franchises from across the MCU, including ones not included in the previous two ''Avengers'' films, in order to both deal with the GreaterScopeVillain of Phases 1-3 (namely ComicBook/{{Thanos}}), and to finally tie off the Infinity Stone MythArc that has been running through TheVerse since mid-Phase 1. It has the largest number of superheroes in any MCU film to date.
** ''Film/AvengersEndgame'' is the direct continuation of the events of ''Infinity War'', climaxing in a BigBadassBattleSequence between the Avengers and their many allies verses Thanos's army.
* ''Franchise/{{Godzilla}}'' has had several:
** ''Film/GhidorahTheThreeHeadedMonster'' is a somewhat smaller-scale version of this. Mothra had already crossed over into the Godzilla universe in ''Film/MothraVsGodzilla'' after having [[Film/{{Mothra}} her own earlier film]], but this one also adds Rodan, who had [[Film/{{Rodan}} his own separate film]], so that all three monsters could team up against King Ghidorah. This also started the tradition of eventually having all of Creator/{{Toho}}'s various {{Kaiju}} [[CanonWelding showing up in this fused universe]].
** ''Film/DestroyAllMonsters'' once again had Godzilla, Mothra and Rodan, but also added other ''Godzilla'' monsters like [[Film/GodzillaRaidsAgain Anguirus]], [[Film/SonOfGodzilla Minilla and Kumonga]], along with other Creator/{{Toho}} monsters like [[Film/KingKongEscapes Gorosaurus]], [[Film/{{Atragon}} Manda]], [[Film/FrankensteinConquersTheWorld Baragon]] and [[Film/VaranTheUnbelievable Varan]], all ultimately fighting King Ghidorah.
** ''Film/GodzillaFinalWars'' features almost every monster introduced in the Showa era facing off against Godzilla.
* ''Film/SpaceJamANewLegacy'' brings together a vast menagerie of Warner Brothers franchises.
* ''Franchise/UltraSeries'' movies tend to do this:
** ''Film/UltramanSaga'' has Franchise/UltramanZero of the M78 universe working together with Series/UltramanDyna and Series/UltramanCosmos, despite the latter two being from completely different dimensions: the reason of their unity is because Dyna summoned them through a dimensional portal. They're working together to defeat Hyper-Zetton, an empowered incarnation of the already powerful monster known as Zetton, after all.
** ''Film/UltramanGingaSTheMovieShowdownThe10UltraBrothers'' features Ultraman Ginga and Victory being trained by the aforementioed Zero, to unleash a more powerful fusion form and release various imprisoned Ultras - ''Series/UltramanTiga'', ''Series/UltramanDyna'', ''Series/UltramanGaia'', ''Series/UltramanMax'', ''Series/UltramanNexus'', ''Series/UltramanMebius'', and his latest addition, ''Series/UltramanCosmos'' - so they may work together and defeat a powerful Space-Time Demon, Etelgar, who intends to enslave Ultras and seeks Ginga, Victory and Zero as latest additions to his collection.
** In ''Film/UltramanXTheMovieHereComesOurUltraman'', Ultraman X ends up working with the original ''Series/{{Ultraman}}'' and ''Series/UltramanTiga'' to defeat Zaigorg, the Ultramen universe equivalent to Satan, who had been unleashed into the world. The ending also features five other Ultras, including Ginga, Victory and Zero, battling Zaigorg's monster army across the globe while X takes on Zaigorg with Ultraman and Tiga assisting him.
** ''Film/UltramanTaigaTheMovieNewGenerationClimax'' takes it UpToEleven, with ''eleven'' Ultra heroes, from Ginga to Taiga, working in tandem in order to destroy the Malicious Demonic Monster Grimdo.

[[folder:Literature]]
* Creator/EugeneSue's 3rd major novel ''Literature/MysteriesOfAPeople'' in its final chapter brings the Hero of [[Literature/MysteriesOfParis his First]] Rodolph into the story as well as the villain of [[Literature/TheWanderingJew his second]] (An Evil Jesuit) to do battle with each other.
* A Creator/JaneAusten version happens in ''Literature/DeathComesToPemberley''. Wickham's situation ends up briefly binding Pride and Prejudice with Persuasion and Emma.
* ''Literature/StarTrekDestiny'': An epic (and we do mean epic) trilogy of novels of the Franchise/StarTrekExpandedUniverse, bringing together characters from ''[[Series/StarTrekTheNextGeneration The Next Generation]]'', ''[[Literature/StarTrekTitan Titan]]'', ''[[Series/StarTrekEnterprise Enterprise]]'', ''[[Series/StarTrekDeepSpaceNine Deep Space Nine]]'' and ''[[Series/StarTrekVoyager Voyager]]'' to tell the story of the apocalyptic final war between the Federation and the Borg.
* The ''Literature/ThursdayNext'' series can be seen as a variant of this in later volumes, with literary characters such as Miss Havisham and the Cheshire Cat playing roles in the salvation of all written literature. It runs closer to a ''Franchise/KingdomHearts''-style crossover than a comic-style crossover, though.
* The first phase of the ''Literature/FamilyChronicles'' have this. ''Literature/HeroesAndVillains'', ''Literature/DeathInTheDEEPS'' and ''Literature/DarknessFalls'' are separate rosters of characters, but the other two books in the phase, ''Literature/BloodAndFire'' and ''Literature/TheBlackestNight'' combine the three separate casts into one fight for the world.
* The GrandFinale of ''Literature/WarriorCats'', ''The Last Hope'' is as close as you can get to a self-contained Crisis Crossover, with loads of screentime for all past and present protagonists, the final battles with all the past villains, and cameos by nearly every [=ThunderClan=] cat from the [[Literature/WarriorCatsTheOriginalSeries first arc]].
* Creator/KimNewman's superhero deconstruction "[[https://johnnyalucard.com/fiction/online-fiction/coastal-city/ Coastal City]]", about what it would actually be ''like'' to live in a typical comicbook universe, mentions that "once a year, there would be a crossover free-for-all, frequently involving something enormously powerful from another galaxy, and all the hypers would destroy the city while saving the universe."
* ''Literature/TheStormlightArchive'' is basically this to the rest of Literature/TheCosmere setting, with planar champions and heroes from previous stories coming together to find Hoid and deal with a threat to the entire Cosmere. Numerous characters and objects from prior books are BackForTheFinale.
* Creator/MichaelMoorcock has the "Agak and Gagak" incident, in which no less than four incarnations of the Eternal Champion (Elric, Erekose, Corum and Hawkmoon) are summoned to fight two {{Eldritch Abomination}}s who threaten the entire Multiverse. It is depicted in two separate novels, from Elric's perspective in ''The Sailor on the Seas of Fate'' and Hawkmoon's in ''The Quest for Tanelorn''.
* ''LightNovel/SDGundamTheLastWorld'' features characters from throughout the ''Franchise/SDGundam'' universe trying to survive an InvoluntaryBattleToTheDeath in the titular "Last World". To wit, alongside [[OriginalGeneration Sen-Pu Ninja Exia and Gundam the Gold]], there's also characters from the ''Knight Gundam'' series, ''Toys/BBSenshiSangokuden'', ''SD Command Chronicles'', ''Anime/SDGundamForce'', ''Gundlander'', and ''SD Gundam Space Time Transfer Gun Voyage'' just to name a few.

[[folder:Live-Action TV]]
!!!'''In General:'''
* ''Series/{{CSI}}'' has been known to cross storylines and characters between its various incarnations, as has the ''Franchise/LawAndOrder'' series. This most commonly takes place during sweeps.
** There was in fact a ''Law & Order'' massive crossover in the works, involving a terrorist plot to attack NYC and several teams of detectives from different squads all working the case together. The idea got shelved after 9/11.
!!!'''By Network:'''
* During the winter of 1999, in line with its plans to air the {{Miniseries}} ''Series/StormOfTheCentury'', Creator/{{ABC}} had a raging winter storm strike all four of its [[SoapOpera soap operas]]. Fitting, as two were set in upstate Pennsylvania, while the other two (one of which was a SpinOff of the other) was set in upstate New York.
!!!'''By Series:'''
* ''Series/AmericanHorrorStoryApocalypse'' is effectively one of these for the ''Series/AmericanHorrorStory'' universe, as it combines several characters and story threads from different seasons (but especially ''[[Series/AmericanHorrorStoryMurderHouse Murder House]]'' and ''[[Series/AmericanHorrorStoryCoven Coven]]'') to reverse its titular apocalypse.
* Creator/TheCW's Series/{{Arrowverse}} has been doing these ever since ''Series/{{The Flash|2014}}'' premiered; it's not uncommon for characters to visit each other, but the ones that air each fall just before the winter break are advertised as big event TV. Originally they were just with the parent show, ''Series/{{Arrow}}'', they've gotten [[SerialEscalation bigger each year]] as more and more shows are added to the franchise. They are in order:
** The 2014 event, ''Series/FlashVsArrow'', where Flash and Arrow face off and visit each other's cities to understand each other better.
** The 2015 event, ''Series/HeroesJoinForces'' was used to promote the third Arrowverse show, ''Series/LegendsOfTomorrow'' by having Teams Arrow and Flash team-up to help Kendra Saunders and [[ComicBook/{{Hawkman}} Carter Hall]] escape the wrath of ComicBook/VandalSavage, the BigBad of ''Legends'' Season 1.
** The 2016 event, ''[[Series/Invasion2016 Invasion!]]'', an adaption of the ''ComicBook/{{Invasion}}'' arc of the 1980's expanded the crossover by having play across all four shows: ''Series/{{Supergirl|2015}}'', ''The Flash'', ''Arrow'', and ''Legends of Tomorrow'' by having Barry Allen unite all the heroes he knows to stop an impending invasion from an alien race called the Dominators.
** The 2017 event, ''Series/CrisisOnEarthX'' is even bigger. Whereas ''Invasion!'' was technically only a three part event (with ''Supergirl'' being just a [[RedSkiesCrossover tie-in]] to the main event), this crossover fully plays out over all four episodes, equally juggling the storylines of each show, as well as serving as a lead-in to ''WesternAnimation/FreedomFightersTheRay''. And it actually has lasting repercussions for the Arrowverse's future, as Barry and Iris get married, as do Oliver and Felicity, while Martin Stein is KilledOffForReal.
** The 2018 event, ''Series/{{Elseworlds|2018}}'', dials things back somewhat, "only" being a crossover between ''The Flash'', ''Arrow'', and ''Supergirl'', though in a surprising twist the [[Series/TheFlash1990 1990 Flash]] ended up making an appearance.[[note]] Legends of Tomorrow was left out for simplicity's sake since ''Crisis on Earth-X'' was a nightmare to coordinate around all four shows' schedule. [[/note]] That said, it is notably a BreatherEpisode compared to the previous year's crossover and is used to promote the then-upcoming''Series/{{Batwoman|2019}}''. Ultimately, it is just [[SequelHook a setup]] for the following year's event.
** The 2019-2020 event is ''Series/{{Crisis on Infinite Earths|2019}}'', having been foreshadowed steadily since ''The Flash'' Season 1 and sporadically throughout the other shows, it featured five episodes that span all recurrent Arrowverse series, including ''Supergirl'', ''Batwoman'', ''The Flash'', ''Arrow'', and ''Legends of Tomorrow'' (the last of these actually began its forthcoming season after the Crisis). This was the last time ''Arrow'' got to participate, as the show ended in 2020 and its final season focuses on {{Tonight|SomeoneDies}} TheHeroDies in the lead-up to and the aftermath of the Crisis. It is an adaptation of the classic [[ComicBook/CrisisOnInfiniteEarths comic of the same name]] AKA the TropeNamer. In addition to the return of 1990 Flash, it also features a cavalcade of guest and cameo appearances from other DC live-action adaptations from outside of the Arrowverse continuity, including Tim Burton's ''[[Film/Batman1989 Batman]]'', ''Series/{{Titans|2018}}'', the 1960s ''[[Film/Batman1966 Batman]]'' series, ''Series/{{Smallville}}'', [[CanonWelding a merger]] of ''Film/SupermanTheMovie'' and ''Film/SupermanReturns''[[note]]The Superman as portrayed by Creator/ChristopherReeve and Creator/BrandonRouth[[/note]], ''Series/{{Birds of Prey|2002}}'', ''Series/{{Lucifer|2016}}'', ''Series/{{Black Lightning|2018}}'', ''Series/{{Swamp Thing|2019}}'', ''Series/{{Doom Patrol|2019}}'' and the Franchise/DCExtendedUniverse. It also marks the debut of the titular character of ''Series/{{Stargirl|2020}}'', [[EarlyBirdCameo ahead of the series' premiere]] on the Creator/DCUniverse streaming service (which includes the aforementioned ''Titans'', ''Doom Patrol'' and ''Swamp Thing'')[[note]]A different version of ComicBook/{{Stargirl|DCComics}} previously appeared in Season 2 of ''Legends of Tomorrow'', played by Creator/SarahGrey[[/note]]. As with the comic book, this crossover has a ''huge'' impact on the franchise, as it ends up merging the ''Black Lightning'' Earth with Earth-38 (the universe where ''Supergirl'' is set) and Earth-1 (where the other four shows are set) into a single new reality.
%%* The 'Proof of Life' crossover between ''Series/TheBill'' and SOKO Leipzig.
* ''Series/TheDefenders2017'' is the self-contained type. It is an eight episode miniseries that sees [[Series/Daredevil2015 Matt Murdock]], Series/{{Jessica Jones|2015}}, Series/{{Luke Cage|2016}}, and [[Series/IronFist2017 Danny Rand]] team up to fight the Hand, a villainous organization built up in ''Daredevil'' season 2 and ''Iron Fist'' season 1. The crossover has lasting repercussions for the next phase of the Netflix shows, as [[spoiler:Matt's "death" in the climax, and subsequent turning up at a convent, sets up the third season of ''Daredevil'' to do a loose adaptation of the renowned ''ComicBook/DaredevilBornAgain'' storyline]].
* ''Series/DoctorWho'':
** Pre-revival, the show would occasionally have multi-Doctor special episodes. They had [[Recap/DoctorWhoS10E1TheThreeDoctors "The Three Doctors"]] (First/Second/Third), [[Recap/DoctorWho20thASTheFiveDoctors "The Five Doctors"]] (First/Second/Third/Fourth/Fifth), and [[Recap/DoctorWhoS22E4TheTwoDoctors "The Two Doctors"]] (Second/Sixth).
** The two-part Series 4 finale, [[Recap/DoctorWhoS30E12TheStolenEarth "The Stolen Earth"]]/[[Recap/DoctorWhoS30E13JourneysEnd "Journey's End"]], crosses over with spinoffs ''Series/{{Torchwood}}'' and ''Series/TheSarahJaneAdventures'', and also brings in almost all of the Doctor's companions to appear in the revived series to date. (Although it should be noted that this did not have any on-screen content or long-term consequences in either of the spin-off shows.)
** [[Recap/DoctorWho50thASTheDayOfTheDoctor "The Day of the Doctor"]] sees the Tenth, Eleventh, and retroactively introduced War Doctors work together to end the Time War. Eventually, [[spoiler:all ''13'' Doctors (including the 12th, yet to debut Doctor) come together to end the Time War and prevent the destruction of the Time Lords.]]
** [[Recap/DoctorWho2017CSTwiceUponATime "Twice Upon a Time"]] has the Twelfth Doctor team up with [[spoiler:his original incarnation, the First Doctor himself]].
* A rather famous "Hurricane Saturday" event that happened on ''Series/TheGoldenGirls'' and its spinoffs ''Series/EmptyNest'' and ''Nurses'' (''Nurses'' was technically a spinoff of ''Series/EmptyNest,'' but go with it.) A hurricane hit during ''The Golden Girls'' and ''Series/EmptyNest'' and the hospital of ''Nurses'' dealt with the aftermath. A similar even happened with a full moon, but that better fit as a CrossThrough.
* Ten years of ''Franchise/KamenRider''[='=]s Heisei era (and much later on, the franchise's 38 years up to that point) were [[MilestoneCelebration celebrated]] in ''Series/KamenRiderDecade'', where Decade (obviously the tenth) must travel across the ''Kamen Rider'' multiverse to save it from total destruction.
** The two-part GrandFinale of ''Series/KamenRiderWizard'' features all fourteen Heisei era Riders up until that point (as well as an EarlyBirdCameo appearance from Series/KamenRiderGaim) teaming up to prevent a new villain from unleashing all of the franchise's past [[MonsterOfTheWeek Monsters of the Week]] upon the Earth.
** The GrandFinale of the Heisei era is ''Series/KamenRiderZiO'', guest starring returning characters from previous series. Zi-O must avoid his fate of becoming an EvilOverlord in the future while preventing the antagonists from successfully grooming a substitute with the [[EvilKnockoff Another Riders]] they create, and the key to both parties' goals lie in the legendary Riders of the past.
* The three crossover episodes that ''Series/NCISNewOrleans'' has shared with its parent show--one of which was its BackDoorPilot--had a case beginning in Washington on ''Series/{{NCIS}}'' before evidence took them to New Orleans.
* ''Franchise/PowerRangers'' has done something like this a few times (not counting traditional two-season teamups), in what was originally meant to be the GrandFinale and as part of [[MilestoneCelebration Milestone Celebrations]].
** The first, ''Countdown to Destruction'' during [[Series/PowerRangersInSpace the sixth season]], featured Dark Specter and the United Alliance of Evil declaring war on the entire universe. While the Space Rangers are the main protagonists, making this a DownplayedTrope, the Aquitar Rangers and Zeo Gold are shown fighting elsewhere.
** Ten Red Rangers would later unite for a special mission in [[Series/PowerRangersWildForce the tenth season,]] to stop the Machine Empire's remaining generals from re-activating Zedd's war Zord Serpentera as part of the 10th anniversary celebration.
** The [[Series/PowerRangersMegaforce twenty-first season]] took the previous ''Rangers'' examples UpToEleven with its GrandFinale ''The Legendary Battle'', where every Ranger team to ever lead a season (including two from other planets, one from the future and one from an AlternateContinuity for some reason) come together to fight an Armada dwarfing the United Alliance of Evil declaring war on Earth. Most of the war is actually off-screen, with the Legendary Rangers fighting and rescuing people elsewhere while the season's own Mega Rangers fight the Emperor and high command; they all come together in time for the final battle against the last remnants of the army. This served as the 20th anniversary celebration, though the post-ChannelHop scheduling of the show delayed it to the 21st year.
* ''Space Squad: Space Sheriff Gavan Vs. Tokusou Sentai Dekaranger'' involves Geki/the new Gavan and the Dekarangers teaming up to fight an alliance between ''Series/MetalHeroes'' villains, with [[Series/KyojuuTokusouJuspion Madgallant]] as the movie's [[BigBad main villain]]. On top of this, the establishment of a space squad was done in response to [[Series/UchuuSentaiKyuranger another universe being dominated by evil]], to prevent such an event from happening again.
* ''Franchise/SuperSentai''. In the seasonal crossovers, the series from ''Series/BakuryuuSentaiAbaranger'' to ''Series/EngineSentaiGoOnger'' are nominally connected by mentions of the Dino House where one character from series A met a character from series B.
** ''Film/KamenRiderXSuperSentaiSuperheroTaisen'' is starting to look like this as well, with ''Decade'''s [[LegionOfDoom Dai-Shocker]] being ressurected, with their opposite number being the similarly-structured Dai-Zangyack Fleet [[spoiler:led by [=GokaiRed=] of the Gokaigers]]. Both the Super Sentai 199 and the All Riders are at the very middle, wondering just what is going on.
** The ''Super Hero Taisen'' series has become an annual tradition, though the focus has been shifting more and more toward the Rider side of things.

[[folder:Magazines]]
* This trope is spoofed in ''Magazine/{{MAD}}''[='=]s article about ''The 8 Greatest Comic Books of All Time'', with one of them being the fake issue ''Multiple Issues: Infinite Identity Countdown to Final Crisis Ad Infinitum: The Introducing''. This issue follows on from ''Exigency Climax: Final Crisis Across Multi-Realities: The Finality'', with every DC Hero from every universe introducing themselves to each other... before the ''next'' crossover event happens.

[[folder:Mythology and Religion]]
* OlderThanFeudalism: The Myth/GreekMythology knows at least two major crossover events: the Argonautica (the story of Jason, the Argonauts, and the Golden Fleece) and the Calydonian Boar Hunt a few years later. Large arc-based events like the Theban Wars and the Trojan War may also count.
* The earliest stratum of Myth/ArthurianLegend drew folk heroes and gods from lots of disparate Celtic myths and legends to form [[BadassArmy King Arthur's court]].
* [[Myth/NorseMythology The [=Æ=]sir-Vanir War]], where the two pantheons of Norse gods the [=Æ=]sir and Vanir ([[MassiveMultiplayerCrossover whom some suggest originated from two different religions that was merged]]) fight and [[CanonWelding ultimately becomes one tribe]], and [[{{Gotterdammerung}} Ragnarök]], where characters from all over Norse mythology meet up to [[KillEmAll kill each-other]].

[[folder:Professional Wrestling]]
* [[Wrestling/TheInVasionAngle The Invasion storyline]] in the Wrestling/{{WWE}} was meant to be this, with top Wrestling/{{WCW}} talent (the then WWF had bought out WCW) "invading" WWF. However contract issues meant that many of the WCW's top stars weren't involved.
* Rather than being involved in every aspect of a single company, The Hostile Youth Project was out to invade every North Carolina promotion in 2002.
[[/folder]]

[[folder:Tabletop Games]]
* ''TabletopGame/TheAbyssalPlague'', a series of ''TabletopGame/DungeonsAndDragons'' {{Tie In Novel}}s which started out in the ''TabletopGame/NentirVale'' setting but grew to involve other ''D&D'' worlds too, including the ''TabletopGame/ForgottenRealms'', ''TabletopGame/{{Eberron}}'' and ''TabletopGame/DarkSun''.
** The D&D settings TabletopGame/{{Planescape}} and TabletopGame/{{Spelljammer}} are made of this trope, explicitly designed to allow travel and storylines across D&D's other universes. While it was implied for years that all D&D games belonged to the same multiverse, these were two official company lines that supported it.
** The book Die, Vecna, Die had the titular lich escape the Mists, leading the party to fight in Greyhawk, across various planes, and culminating in an attack on Sigil. Canonically, this module is the story reason for the changes from 2nd Ed. to 3rd.
* The ''TabletopGame/OldWorldOfDarkness'' had a few thematic ones toward the end of its line, but an official one with the Time of Judgment series of books, officially ending the old settings.
* TabletopGame/{{Rifts}} is this to the Palladium systems of games. The setting is of Earth a couple hundred years in the future, after having been transformed into a multidimensional hub, with beings from all over time and space arriving, either by choice or forcibly.
** More specifically, Palladium ran a series of {{Sourcebook}}s called "Minion Wars," detailing a conflict between two different versions of Hell that spilled out across the [[{{Multiverse}} Megaverse]]. Sourcebooks were written for several Palladium titles, describing how those specific settings were affected by the war.
* [[RealityStorm Reality Storm: When Worlds Collide]], a crossover between TabletopGame/{{Silver Age Sentinels}} and TabletopGame/{{Champions}}.
* In ''TabletopGame/{{Wargames}}'', characters and factions beating the crap of each other is their entire point, but sometimes events in the story get too out of hand and several facions are drawn into the ensuing conflict. These wars are commonly told in special supplements commonly named "Campaign Books". These books usually include the background of the conflict, special rules and scenarios to replicate in the tabletop the battles of the mentioned conflict and the rules of units, soldiers and characters who got involved in said conflict, regardless of faction or allegiance. Sometimes, these camapigns and their resolution gets it's way into the story itself and becomes a part of it, specially in the ficitional wargames.
** Years ago, Creator/GamesWorkshop hosted events called "World Campaigns" which involved every faction of their main games ''TabletopGame/{{Warhammer}}'' or ''TabletopGame/{{Warhammer 40000}}'' and threw them into a war where everyone had someting at stake, with different levels of focus (Usually both Empires being the highest) in the story. These campaigns were to be played by players all around the world and games deciding (usually) the outcome of said wars. Some Campaigns were reinforced by Campagin books like normal campaigns. The most famous are included in their games entries.
*** 40K had campaign suppements way back to [[OlderThanTheyThink 2nd Edition]], like Storm of Vengeance, but other, more recent ones are ''Armageddon'' and ''Eye of Terror'' related to the World campaign of the same name. The most recent ones are ''The Red Waagh'' and ''Shield of Baal'' series of books and boxed sets wich the firt Series pits the Astra Militarum, and Space Wolves aganist the Orks, and the second the Astra Militarum, Sisters of Battle, Blood Angels [[spoiler:and Necrons]] aganist the Tyranids.
*** ''Warhammer'' also had its share of campaigns, usually in the form of "campaign boxes", normally centered in two or three of the factions that included the campaign books and special markers or scenery, all capboard. Some of most famous of these Campaign boxes are ''Idol of Mork'' and ''Tears of Isha''. 6th Edition onwards, the campaign box format was dropped in favor of the traditional book, being the most famous campaigns ''The Shadow over Albion'', ''Storm of Chaos'' and ''The Nemesis Crown'' also World Campaigns (albeit The Nemesis Crown was {{retconned}} the istant the campaign ended and Storm of Chaos suffered the same fate in the beggining of 8th Ed., The Shadow over Albion sticked). The most famous ([[BrokenBase and controversial]]) of the recent campaigns is the ''TabletopGame/WarhammerTheEndTimes'' series of books. The End times tells the story of [[TheEndOfTheWorldAsWeKnowIt the final days of the world]] and the efforts of EVERYONE to stop it or bring it. No one knows for sure if it will stick, but everyone fears that it will. No need to say that [[ApocalypseHow it didn't end well]].
[[/folder]]

[[folder:Video Games]]
* ''VideoGame/TheKingOfFighters'' series of fighting games is a Crisis Crossover for Creator/SNKPlaymore, featuring characters from ''VideoGame/ArtOfFighting'', ''VideoGame/FatalFury'', ''VideoGame/IkariWarriors'' and ''VideoGame/PsychoSoldier'', as well as creating several characters exclusive to the series (Iori Yagami, Kyo Kusanagi, and [[SNKBoss Rugal Bernstein]] being the most notable).
* The Subspace Emissary story mode in ''VideoGame/SuperSmashBrosBrawl''. It involves all of Nintendo's major heroes ([[GuestFighter and a couple of others]]) teaming up to stop the titular Subspace Emissary from destroying the ''Smash Bros.'' universe. However, unlike the typical Crisis Crossover, this explicitly takes place in an AlternateContinuity where the characters are all trophies that come to life and fight.
** ''VideoGame/SuperSmashBrosUltimate'' brings together every single Smash Bros. fighter ever, plus a few new ones, to take down the "ultimate enemy" named Galeem [[spoiler:and his [[EvilVersusEvil just-as-evil counterpart]] Dharkon.]]
* ''VideoGame/DissidiaFinalFantasy'' has the evil god Chaos revive villains from ''VideoGame/FinalFantasyI'' through ''VideoGame/FinalFantasyX'' in an attempt to sieze the Crystals and change history. Chaos' opposite number, the goddess Cosmos, calls on the heroes from the same games to unite and save the universe.
* ''[[VideoGame/GundamVsSeries Gundam Vs. Gundam NEXT]]'' has the [[Anime/MobileFighterGGundam Devil Gundam]] come to life and take over arcade games representing the entire ''Franchise/{{Gundam}}'' franchise from [[Anime/MobileSuitGundam the original series]] through ''[[Anime/MobileSuitGundam00 Gundam 00]]'', forcing the characters to team up to deal with the threat.
* This is arguably how ''VideoGame/SuperRobotWars'' works, except it's ''also'' a Crisis Crossover between entirely separate companies. A more conventional Crisis Crossover would be the case if Anime/GaoGaiGar and Betterman ever were in the same game, since they were in the same Universe to begin with.
* ''[[Franchise/DotHack .hack//Link]]'' is going this way, as characters from both of the "revisions" of The World are in it. (Tokkio's first two party members are Tsukasa from SIGN and Haseo from G.U., for example.)
* The ''VideoGame/NicktoonsUnite'' series serve as this for {{Creator/Nickelodeon}}, with WesternAnimation/SpongebobSquarepants, WesternAnimation/DannyPhantom, [[WesternAnimation/TheAdventuresOfJimmyNeutronBoyGenius Jimmy Neutron]] and one or two other universes deal with a multiuniversal threat, differing each game.
** As for Nick's rival Creator/CartoonNetwork, they have the MMORPG ''VideoGame/FusionFall'', though its art style makes it clear it is an AlternateUniverse.
* Similiary to the ''Kamen Rider Decade'' example above, ASCII Media Works celebrated the 15th anniversary of their Dengeki Bunko imprint of LightNovels with the UsefulNotes/NintendoDS RPG ''Dengeki Gakuen RPG: Cross of Venus'', where an evil organization is attempting to derail the storylines of eight of their series and so your [[HelloInsertNameHere not-so-nameless]] protagonist and [[LightNovel/ShakuganNoShana Shana]] must form a rag-tag group with their worlds' heroines to save their printed existences.
* Inverted in ''VideoGame/PokerNightAtTheInventory'', where Strong Bad, Max, The Heavy, and Tycho (from ''WebAnimation/HomestarRunner'', ''VideoGame/SamAndMaxFreelancePolice'', ''VideoGame/TeamFortress2'', and ''Webcomic/PennyArcade'' respectively) team up to [[ExactlyWhatItSaysOnTheTin play poker]]. The sequel has Brock Samson, [=CL4P-TR4P=], Ash Williams, Sam, and [=GLaDOS=] (from ''WesternAnimation/TheVentureBros'', ''VideoGame/{{Borderlands}}'', ''Franchise/EvilDead,'' ''VideoGame/SamAndMaxFreelancePolice'', and ''VideoGame/{{Portal}}'', respectively.)
* The ''VideoGame/MarvelVsCapcom'' series is this for both Marvel and Capcom.
** The original ''VideoGame/MarvelVsCapcomClashOfTheSuperheroes'' reused the plot of the ''Onslaught'' saga and adding in Capcom characters.
** ''VideoGame/MarvelVsCapcom2'' has a more straightforward plot where Ruby Heart was gathering characters from both companies to deal with [[OmnicidalManiac Abyss]].
** ''VideoGame/MarvelVsCapcom3'' has [[VideoGame/ResidentEvil Wesker]] and Doctor Doom team up, crossing over the Marvel and Capcom universes, and awakening ComicBook/{{Galactus}} in the process.
** ''VideoGame/MarvelVsCapcomInfinite'' has Death and [[VideoGame/{{Darkstalkers}} Jedah Dohma]] intend to fuse the two worlds together, result in a fusion of Ultron and [[VideoGame/MegamanX Sigma]] with 2 of the Infinity Stones seek to dominate all life.
* The ''VideoGame/{{Suikoden}}'' series is headed this direction nowadays, but with original characters in an attempted re-invention. ''VideoGame/SuikodenTierkreis'' introduced the multiverse concept and the next game is said to be focused around this.
* ''VideoGame/ResidentEvil6'' is this for the ''Franchise/ResidentEvil'' franchise. Including Leon Kennedy, Chris Redfield, [[WildCard Ada Wong]], and even [[TheBusCameBack the returned Sherry Birkin]] and a son of Albert Wesker, all face off against a new, global bioterrorism threat, rather than confined to certain locations to chase down a singular threat.
* ''VideoGame/EndWar'' is one of these for the Creator/TomClancy [[TheVerse game verse]], including former members of the [[VideoGame/GhostRecon Ghosts]] and [[VideoGame/RainbowSix Rainbow]], along with the VideoGame/{{HAWX}} squadron and [[VideoGame/SplinterCell Third Echelon]].
* ''VideoGame/MagicalGirlLyricalNanohaAsPortable: The Gears of Destiny'', which featured an unstable HumanoidAbomination whose out of control powers dragged in characters across time and space and produced {{Virtual Ghost}}s of dead people, incidentally allowing characters from the various recent installations of the franchise at the time (''[[Anime/MagicalGIrlLyricalNanoha The Movie First]]'', ''[[Manga/MagicalGirlLyricalNanohaVivid Vivid]]'', and ''[[Manga/MagicalRecordLyricalNanohaForce Force]]'') to join in the fray against the new threat.
* As part of Creator/ArtixEntertainment's 10th anniversary celebration, six of their active online games at the time (''VideoGame/AdventureQuest'', ''VideoGame/DragonFable'', ''VideoGame/MechQuest'', ''VideoGame/AdventureQuestWorlds'', ''VideoGame/EpicDuel'', and ''VideoGame/HeroSmash'') [[KayFabe were attacked by Chairman Platinum and his company, EbilCorp]], sparking a cooperative war in which the playerbases of all six games had to band together as one and eliminate the invading forces in every single game within a week. [[spoiler: The players won.]]
** Prior to this, there was a St. Patrick's Day event [[YouMeanXmas (known in game as the Blarney War or Lucky War in-universe)]] that united the ''[=AdventureQuest=]'', ''[=DragonFable=]'', and ''[=MechQuest=]'' timelines [[DisasterDominoes in a successive war]], and a war against Shearhide that was a crossover between ''[=AdventureQuest=]'' and ''VideoGame/WarpForce''.
* Bringing the tradition into video games, ''VideoGame/MortalKombatVsDCUniverse'' has a plot along these lines with {{ComicBook/Darkseid}} being somehow and involuntarily [[FusionDance merged]] (for the third time), now with Shao Kahn into an HumanoidAbomination who grinds the two universes into destruction just by ''existing''. Midway considers it an {{Elseworld}} for the DC side of the story, though they did write the ''Kombat'' side so as to implicitly fit in between ''VideoGame/MortalKombat3'' and ''VideoGame/MortalKombat4'' (as well as hand it a ContinuityNod in ''VideoGame/MortalKombat9'': the Training Mode description for Shang Tsung's M-rated CaptainErsatz version of ComicBook/TheJoker's gun fatality is "Shang Tsung has picked up a few tricks from previous opponents."). In real life, the crossover had the effect of Creator/WarnerBros, DC's parent company, being allowed to acquire Midway's ''Mortal Kombat'' division (now named Netherrealm Studios) when Midway went bankrupt.
* Though ''VideoGame/JumpSuperStars'' and its sequel have an ExcusePlot, it still does amount to [[spoiler: Dr. Mashirito from ''Manga/DoctorSlump'']] stirring up trouble, while the J-Heroes/Heroines try to stop him.
* What could possibly be powerful enough that all of the numbered ''Franchise/ShinMegamiTensei'' protagonists, each of which powerful enough to fight against [[{{God}} YHVH]] Himself, would have to team up with [[VideoGame/ShinMegamiTenseiIVApocalypse Nanashi]], who actually ''does'' [[KillTheGod kill Him]]? Of course none other than [[spoiler:Stephen, establishing his position as AllPowerfulBystander once and for all with a boss fight that is essentially YHVH [[UpToEleven on steroids]]]].
* The crossover event ''LightNovel/AccelWorld vs LightNovel/SwordArtOnline: Millennium Twilight'', involves the Accel World and Sword Art Online characters being brought together and being forced to team-up against the threat that transcends time, [[BigBad Persona Vabel]].
* ''VideoGame/FateGrandOrder'' features nearly every Servant, and many non-Servant characters (some now summonable as Servants), from ''VisualNovel/FateStayNight'', ''LightNovel/FateZero'', ''VideoGame/FateExtra'', ''LightNovel/FateApocrypha'', and even ''Anime/FatePrototype'' and ''Manga/FateKaleidLinerPrismaIllya'', in a storyline where the Chaldea Security Organization must fix time anomalies that could destroy the world. There are even characters from non-''Fate'' works such as ''LightNovel/TheGardenOfSinners''.
* The ''VideoGame/DetectivesUnited'' series is this for three of the Creator/ElephantGames mystery game series (''Haunted Hotel, Mystery Trackers'', and ''Grim Tales''), with the three player characters coming together to combat supernatural forces that even their individual OccultDetective skills would not be able to overcome.
* ''[[VideoGame/MagiaRecordPuellaMagiMadokaMagicaSideStory Magia Record]]'' brings in all notable magical girls from the entire ''Franchise/PuellaMagiMadokaMagica'' franchise, including ''[[Manga/PuellaMagiKazumiMagica Kazumi Magica]]'', ''[[Manga/PuellaMagiOrikoMagica Oriko Magica]]'', ''[[Manga/PuellaMagiTartMagica Tart Magica]]'', and ''[[Manga/PuellaMagiSuzuneMagica Suzune Magica]]''. In addition to a [[LoadsAndLoadsOfCharacters rather large cast]] of new characters. Most spinoff characters only appear in side-stories (within the game) and are not directly involved in the main storyline, but they all interact with ''Magia Record'''s main cast in some way.
* ''Worlds Align'' is this for [[Creator/ERSGameStudios AMAX Interactive]]. It posits that their games each take place in separate dimensions, which are connected, and the heroes of each series are "Watchers" who protect their worlds. When a great evil threatens the worlds of ''VideoGame/DarkTales, VideoGame/{{Puppetshow}}'', and ''Haunted Halls'', they reach out to another Watcher - the player, who has been appointed to this role for the "real world." You actually play the games ''as yourself'', assisting characters in ending the crisis, with NoFourthWall keeping the characters from acknowledging that you're a real person who knows them from games.
[[/folder]]

[[folder:Webcomics]]
* In late 2008, ''Webcomic/IrregularWebcomic'' had most of its separate "themes" converge when [[TemporalParadox simultaneous paradoxes]] occur and the universe imploded. Eventually the characters managed to restart the universe, but most themes suffered a ContinuityReboot in the process.
** It appears another one is in the works, with several characters being transported to the 1940s, and the recurring {{Arc Word|s}} "Greatness is often linked with insanity."
* ''Webcomic/LeastICouldDo'' parodied this with the storyline "Ultimate Final Civil War Invasion Crisis Thing", where the gaming webcomics (including ''Webcomic/PennyArcade'' and ''Webcomic/CtrlAltDel'') are attempting to take out the "straight comedy" comics and reassert their dominance. Receives several [[LampshadeHanging lampshades]], such as when [[Webcomic/QuestionableContent Faye]] calls the plot weak, and Rayne counters, "So was a cosmic vampire, but that didn't stop [[Creator/DCComics DC]]."
* When Emily and Tesrin of ''Webcomic/AllOverTheHouse'' [[http://www.alloverthehouse.net/2009/12/04/unscheduled-stop/ crash-landed]] in ''Webcomic/TheLifeOfNobTMouse'', it kick-started a crossover that changed both comics permanently.
* Webcomic/TheCrossoverlord is one between several superhero webcomics, including ''{{Webcomic/Lightbringer}}'', ''Webcomic/MechagicalGirlLisaANT'' , ''Webcomic/{{Mindmistress}}'', ''Webcomic/{{Dasien}}'' and Dead Debbie from ''Indefensible Positions''. The sequel, ''Webcomic/{{Crossoverkill}}'', retains {{Webcomic/Mindmistress}} and adds {{Webcomic/Energize}}, Yuuki from ''Sparkling Generation Valkyrie Yuuki'', [[EssayBeeComicsPresentsFusion Fusion]], Captain Perfect from ''Webcomic/BadGuyHigh'', MajesticKnight and ''Webcomic/MagellanHoodoo''.
[[/folder]]

[[folder:Web Original]]
* ''Webcomic/DeviantartSecretWars''
* WebVideo/TGWTGYearOneBrawl, WebVideo/{{Kickassia}}, WebVideo/SuburbanKnights, and WebVideo/ToBoldlyFlee from the people at Website/ThatGuyWithTheGlasses.
* These have become the ''main'' storyline in WebVideo/ImAMarvelAndImADC, as is to be expected in a meta series for both Marvel and DC. Having Deadpool around means that inter-series continuity is now lampshaded.
* Several in ''Roleplay/MarvelsRPG''.
* The blogosphere side of Franchise/TheSlenderManMythos has had a few. Some examples include the Winter Solstice story in ''Blog/ObserveAndTerminate'' and ''Blog/AHintOfSerendipity'', and the Wedding crossover from ''Take The Myth''.
* Franchise/TheFearMythos, a spin-off of Franchise/TheSlenderManMythos, had one early in its existence: The Birth of the Manufactured Newborn. It involved four different blogs intertwining their stories: ''The Hunter'', ''The Devil and God Are'', ''They Sought It With Thimbles'', and ''Blog/HiddenInTheTrees''. The crossover involved a conspiracy by the [[EldritchAbomination Fears]] to birth a new one into their ranks, while the human characters either try to stop them or try to help them.
[[/folder]]

[[folder:Western Animation]]
* ''WesternAnimation/DextersLaboratory'': ''Last But Not Beast'' had the Dexter, Monkey and Justice Friends segments connected via the giant monster destroying Japan. The Monkey segment even skips its usual opening credits to continue the story.
* ''WesternAnimation/TurtlesForever'': It deals with the [[WesternAnimation/TeenageMutantNinjaTurtles2003 2000 Shredder]] returning from his exile, taking over the [[WesternAnimation/TeenageMutantNinjaTurtles1987 1980s Shredder's Technodrome]], and, after learning of the [[TheMultiverse TMNT Multiverse]], he plans to go conquer it, until [[GoMadFromTheRevelation he learns that]] ''there are teams of TMNT in each and every reality''. He goes after the [[ComicBook/TeenageMutantNinjaTurtlesMirage original Mirage Turtles]] in order to destroy all the Turtles, and three seats of Turtle Teams set off to stop him.
* Creator/HannaBarbera did this with the "Council of Doom" storyline in ''WesternAnimation/SpaceGhost'' with Space Ghost eventually meeting ''[[WesternAnimation/MobyDickHannaBarbera Moby Dick]]'', ''WesternAnimation/MightyMightor'', ''WesternAnimation/{{Shazzan}}'', and ''WesternAnimation/TheHerculoids''. Sometimes, the Cartoon Network (and later, Boomerang) would show the whole thing.
** The later ''WesternAnimation/SpaceStars'' series did this at the end of each show with a "Space Stars Finale" which features a team up of characters from two or more of the show's segments (Teen Force, Space Ghost, The Herculoids, and [[WesternAnimation/TheJetsons Astro]] and the Space Mutts).
* Another Creator/HannaBarbera example would be ''WesternAnimation/YogisArkLark'' which by definition featured characters joining together to deal with a crisis. Except the crisis in question wasn't a comic book level event as much as the planet has too much pollution kind.
* The Phoenix Saga of the ''WesternAnimation/XMen'' animated series was a borderline example. Although there were no actual team ups, it used appearances of other Creator/MarvelComics characters to emphasise the seriousness of the whole thing. [[{{Comicbook.Excalibur}} Captain Britain]] and Comicbook/DoctorStrange were seen reacting to the Phoenix and Franchise/SpiderMan (albeit only his silhouette and his hand) and [[ComicBook/IronMan War Machine]] were seen protecting civilians in [[BigApplesauce New York]]. In the sequel, the Dark Phoenix Saga, Doctor Strange briefly appeared again, along with [[ComicBook/TheMightyThor Thor]], a Watcher and Eternity.
* A made-for-TV animated movie called ''WesternAnimation/TheManWhoHatedLaughter'' brought together a big group of ''newspaper'' comic strip characters -- ComicStrip/{{Blondie}}, ComicStrip/{{Popeye}}, ComicStrip/BeetleBailey, ComicStrip/HiAndLois, ComicStrip/SnuffySmith -- who are ultimately saved from a comics-hating villain by the combined forces of a group of newspaper adventure strip heroes (ComicStrip/MandrakeTheMagician, ComicStrip/FlashGordon, ComicStrip/PrinceValiant, ComicStrip/ThePhantom, and ComicStrip/SteveCanyon). All the characters are owned by King Features Syndicate.
* Hurricane Flozell blew her way into all three Creator/SethMacFarlane shows, ''WesternAnimation/TheClevelandShow'', ''WesternAnimation/FamilyGuy'' and ''WesternAnimation/AmericanDad'' culminating in the final scene of the ''American Dad'' episode where Cleveland, Stan, and Peter have a standoff with guns.
* The feature-length special ''WesternAnimation/RudolphAndFrostysChristmasInJuly'' by Creator/{{Rankin Bass|Productions}}, which brought back several characters from all of their holiday specials and many of the voice actors from the previous specials as well. It involves Rudolph, Frosty, and Santa trying to stop an evil wizard named Winterbolt. It also contains a bounty of ContinuityPorn, with callbacks to other previous specials such as ''Santa Claus is Comin' to Town'', ''WesternAnimation/RudolphsShinyNewYear'', and ''Frosty's Winter Wonderland'' (with the notable exception of ''The Year Without a Santa Claus'', leaving the poor Miser Brothers snubbed).
* ''WesternAnimation/SpiderManTheAnimatedSeries'': While the show had many crossovers, the series had two of this nature near the end of it's run. "Secret Wars" which saw Spider-Man drafted to be a leader in a literal battle of good vs evil where he picks the Fantastic Four, Storm, Captain America, Black Cat and Iron Man to help take on the likes of Dr. Doom, Dr. Octopus, The Lizard, Alister Symthe and Red Skull. The final arc of the series, "Spider Wars", saw him teaming with various Spider-Men from different alternate universes (one with eight arms, one with Doc Ock's metal tentacles, one who was a billionaire and built his own tech, one who didn't have any powers, and one who was the Scarlet Spider) to stop Spider-Carnage, a murderous version of Spider-Man who fused with the Carnage symbiote.
* ''WesternAnimation/TeenTitansGoVsTeenTitans'' features the 2013 Teen Titans meeting up with their 2003 counterparts to do battle against both Go!Trigon and a freshly resurrected 2003 Trigon. Multiple incarnations of Teen Titans throughout the multiverse are eventually summoned to do battle with this new threat alongside the two main teams.
[[/folder]]

* ''TabletopGame/TheAbyssalPlague'', a series of ''TabletopGame/DungeonsAndDragons'' {{Tie In Novel}}s which started out in the ''TabletopGame/NentirVale'' setting but grew to involve other ''D&D'' worlds too, including the ''TabletopGame/ForgottenRealms'', ''TabletopGame/Ebberon'' and ''TabletopGame/DarkSun''.

* ''Franchise/UltraSeries'' movies tend to do this:
** ''Film/UltramanSaga'' has Franchise/UltramanZero of the M78 universe working together with Series/UltramanDyna and Series/UltramanCosmos, despite the latter two being from completely different dimensions: the reason of their unity is because Dyna summoned them through a dimensional portal. They're working together to defeat Hyper-Zetton, an empowered incarnation of the already powerful monster known as Zetton, after all.
** ''Film/UltramanGingaSTheMovieShowdownThe10UltraBrothers'' features Ultraman Ginga and Victory being trained by the aforementioed Zero, to unleash a more powerful fusion form and release various imprisoned Ultras - ''Series/UltramanTiga'', ''Series/UltramanDyna'', ''Series/UltramanGaia'', ''Series/UltramanMax'', ''Series/UltramanNexus'', ''Series/UltramanMebius'', and his latest addition, ''Series/UltramanCosmos'' - so they may work together and defeat a powerful Space-Time Demon, Etelgar, who intends to enslave Ultras and seeks Ginga, Victory and Zero as latest additions to his collection.
** In ''Film/UltramanXTheMovieHereComesOurUltraman'', Ultraman X ends up working with the original ''Series/{{Ultraman}}'' and ''Series/UltramanTiga'' to defeat Zaigorg, the Ultramen universe equivalent to Satan, who had been unleashed into the world. The ending also features five other Ultras, including Ginga, Victory and Zero, battling Zaigorg's monster army across the globe while X takes on Zaigorg with Ultraman and Tiga assisting him.
** ''Film/UltramanTaigaTheMovieNewGenerationClimax'' takes it UpToEleven, with ''eleven'' Ultra heroes, from Ginga to Taiga, working in tandem in order to destroy the Malicious Demonic Monster Grimdo.

* ''Film/SpaceJam2ANewLegacy''.

** The actual crossover itself was integrated fully (as in, no denying it anymore) into DC continuity with the release of ''Trinity'' #7, with the Avengers being referred to as the "Others"; you can even see what seems to be a silhouette of ComicBook/CaptainAmerica in one panel (though it's just as believable to think that was Comicbook/TheFlash - it's left rather vague). Krona's fate at the end of the crossover also played a part in a few ''JLA'' stories after.

%%* The Amalgam Universe had its own crisis crossover: ComicBook/SecretWars1984, ComicBook/CrisisOnInfiniteEarths, ComicBook/TheInfinityGauntlet, and ComicBook/ZeroHour.

* ''Anime/DigimonXrosWarsTheYoungHuntersWhoLeaptThroughTime'' has one in its final few episodes, which saw the return of all the leaders and various other members of all previous Digimon-teams.

* ''ComicBook/LegendsDC'' (1987): This series was a crossover in which the evil god ComicBook/{{Darkseid}} tries to turn humanity against all its superheroes; it doesn't take. ''Legends'' was most notable for launching the semi-humorous ''[[ComicBook/JusticeLeagueOfAmerica Justice League International]]'' (the one with Comicbook/BlueBeetle) and the perennially popular supervillains-doing-espionage title ''ComicBook/SuicideSquad'', as well as starting the career of third Comicbook/TheFlash, Wally West. It also marked the post-Crisis debuts of Franchise/WonderWoman (after she was rebooted from scratch by George Perez and Greg Potter) and [[ComicBook/{{Shazam}} Captain Marvel.]]

** In ''Cosmic Odyssey'' (ironically the only one that was self-contained), Darkseid, the ComicBook/NewGods, and a group of super-heroes fight a giant shadow that Metron claims is the Anti-Life Equation's true form. Outside of [[ComicBook/GreenLantern John Stewart]] (no, not ''[[Series/TheDailyShow that]]'' one) acting like a rookie and causing an entire planet to explode due to his hubris, [[CanonDiscontinuity no one likes to talk about this story]] since making the Anti-Life Equation a giant shadow monster was a stupid idea.
** In ''Comicbook/{{Millennium}}'', the robotic Manhunters try to stop the Guardians of the Universe from giving a group of really bad ethnic stereotypes virtual Godhood; it doesn't work out. By contractual obligation, at least one secondary character from most of DC's titles turned out to be [[TheMole the Manhunters' moles]][[note]](In ''{{Superman}}'', basically all of Smallville but the Kents.)[[/note]], which was never mentioned again afterwords.

** ''ComicBook/{{Armageddon 2001}}'': One of DC's top super-heroes will become the uber-villain "Monarch"! Except the ending (it was ComicBook/CaptainAtom) gets leaked, meaning [[ShockingSwerve third-string character Hawk became Monarch instead]]. Monarch promptly disappeared until three years later, when he was retooled as Extant and became a flunky for A-List hero [[ComicBook/GreenLantern Hal Jordan]], who went evil in the wake of ''ComicBook/TheDeathOfSuperman''.

* ''ComicBook/ZeroHour: Crisis in Time'' (1994): For this one, DC ended up pressing the reset button ''again''. WellIntentionedExtremist Parallax (a.k.a. [[ComicBook/GreenLantern Hal Jordan]]) plans to destroy the entire DC Universe and remake it [[SetRightWhatOnceWentWrong in his image]]. Unlike ''ComicBook/CrisisOnInfiniteEarths'', ''Zero Hour'' ended up changing relatively little (aside from completely rebooting [[Comicbook/{{LegionOfSuper-Heroes}} The Legion Of Super-Heroes]] and making ComicBook/{{Hawkman}}'s continuity [[ContinuitySnarl even more confusing]]) and a massive bus being dropped onto the Justice Society of America. And unlike ''ComicBook/CrisisOnInfiniteEarths'', ''Zero Hour'' was met with mixed reviews.
* ''Worlds Collide'' (1994): This was a major DC Comics[=/=]Creator/MilestoneComics crossover, which had to be handled carefully, since the DC characters were comics in the Milestone universe. It was a scintillating series in that the differences between similar characters such as {{Superman}} and ComicBook/{{Icon}} were examined. Perhaps the most entertaining was the relationship between Comicbook/{{Hardware}} and ComicBook/{{Steel}}, who had the same abilities and skills, but were at opposite ends of the SlidingScaleOfIdealismVersusCynicism. Since then, Milestone was folded into the DC universe, which seems even more poignant after the passing of Creator/DwayneMcDuffie.

* 1995's ''ComicBook/UnderworldUnleashed'' saw Mark Waid killing off 90% of Comicbook/TheFlash's rogue's gallery who he felt were too silly even for his [[UsefulNotes/TheSilverAgeOfComicBooks Silver Age]] tastes (though this didn't last long and Waid was proven wrong in a BIG way later on) and introducing Neron, the ''de facto'' Satan of the DC Universe proper. It also saw a ton of DC villains [[DealWithTheDevil selling their souls]] for grim and gritty revamps, of which only a small handful actually stuck.

** ''ComicBook/JokersLastLaugh'', tied very much to the other crossover (almost literally starting after ''Our Worlds At War'' had ended). This story had Joker infect all of the DC Universe's villains with chemicals turning them into Joker-lite mass murderers, after Joker is [[InducedHypochondria falsely told he has terminal cancer]]. Two notable scenes are when Joker {{Lampshade}}s previous crises by desiring red skies for his plan, and Chuck Dixon spending the entire storyline effectively cursing out readers for asking why no one kills the Joker.
* ''ComicBook/IdentityCrisis'' (2004): This was the first book to use "Crisis" in its title since ''Zero Hour''. It was a crossover, but not necessarily a ''crisis'' crossover -- in fact, it was a very low-key murder mystery far more concerned with buried secrets and the personal lives of heroes than with blowing stuff up -- but it did end up changing things, due to the nature of the secrets revealed rather than any cosmic shenanigans. It's also notable as it deretconed back into existence many pre-ComicBook/{{Crisis|on Infinite Earths}} story lines from the Silver and Bronze ages, but at the same time made them DarkerAndEdgier. It turned B-list Comicbook/TeenTitans Villain Dr. Light into a [[MemeticMolester rapist]], [[RetCon revealing]] that his "bumbling" and "pathetic" status was the result of a magically induced lobotomy. The story was eventually revealed to be the first part of a trilogy to "explore the DC heroes" in which they were put up against "a very personal threat". Its repercussions were felt throughout Franchise/TheDCU (leading to mini-Crisis Crossovers such as ''[[ComicBook/SecretSix Villains United]]'' and the ''Day of Judgement'' sequel ''[[ComicBook/{{Shadowpact}} Day of Vengeance]]'') until they coalesced in:

* ''ComicBook/FiftyTwo'' (2006-7): Basically the final act of the storyline of ''ComicBook/IdentityCrisis'' and ''ComicBook/InfiniteCrisis'' (story-wise). Innovative for its use of real time continuity, tossing ComicBookTime out the window in favor of the ''Series/TwentyFour'' approach, published weekly, from May 2006 to May 2007, each issue represents a week of time in-universe, covering the "missing year" of the DCU, as after ''Infinite Crisis'', all books were jumped forward "One year later". Written by a "dream team" of four writers (Creator/GeoffJohns, Creator/GregRucka, Creator/MarkWaid, and Creator/GrantMorrison, each of whom contributed something to every issue.) it also followed the lives of minor characters of the DCU while the "Big Three" Batman, Superman, and Wonder Woman took the year off for various reasons, Widely considered to be one of the greatest story lines of UsefulNotes/{{the Modern Age|OfComicBooks}}. It also introduced the Modern Batwoman, and Renee Montoya as ComicBook/TheQuestion.

* ''ComicBook/BlackestNight'' (2009): Following on from the events of the epic ''ComicBook/SinestroCorpsWar'' storyline that [[EnsembleDarkhorse proved to be infinitely more popular]] than the ''Countdown'' event that was happening at the same time, the culmination of a prophecy first mentioned in an Creator/AlanMoore penned back-up strip in "Tales of the [[ComicBook/GreenLantern Green Lantern Corps]]" back during the 80s. The best way to describe it is as SpaceOpera [[JustForFun/XMeetsY meets]] ZombieApocalypse. As dead super heroes, super villains, and their families and friends are brought back to life by Nekron, the various color corps from Geoff Johns' run on Green Lantern must put aside their differences and fight to protect all life in the universe. While being heavily ComicBook/GreenLantern[=-centric=], it crosses over with the entire DCU. Most books had at least one issue involved with the event.\\

* ''ComicBook/{{Flashpoint}}'' (2011): This is to ComicBook/TheFlash what ''ComicBook/BlackestNight'' was to ComicBook/GreenLantern. Barry Allen has woken up to find reality changed around him; now he needs to find out ''what the heck happened?'' His discovery of the truth behind the altered world quickly leads to [[ComicBook/{{New 52}} a line-wide reboot on a scale]] not seen since the original ''Crisis''.

** ''ComicBook/DarkNightsMetal'' is the culmination of Creator/ScottSnyder's Batman run, in which the Justice League comes face to face with a "Dark Multiverse," with the crossover restoring many [[TheBusCameBack elements and characters]] that have been missing since the New 52 began.

* Zenescope is currently in the middle of its first ever Crisis Crossover, ''The [[NamesToRunAwayFromReallyFast Dream Eater]] Saga''. A threat so major that even [[CardCarryingVillain Belinda]] and [[AxCrazy The Queen of Hearts]] are fighting against it.*

* Creator/TheCW's ''Series/{{Arrowverse}}'' has been doing these ever since ''Series/TheFlash2014'' premiered; it's not uncommon for characters to visit each other, but the ones that air each fall just before the winter break are advertised as big event TV. Originally they were just with the parent show, ''Series/{{Arrow}}'' they've gotten [[SerialEscalation bigger each year]] as more and more shows are added to the franchise. They are in order:

** The 2015 event, ''Series/HeroesJoinForces'' was a BackdoorPilot for the third Arrowverse show, ''Series/LegendsOfTomorrow'' by having Teams Arrow and Flash team-up to help Kendra Saunders and [[ComicBook/{{Hawkman}} Carter Hall]] escape the wrath of ComicBook/VandalSavage.
** The 2016 event, ''Series/Invasion2016'', an adaption of the ''ComicBook/{{Invasion}}'' arc of the 1980's expanded the crossover by having play across all four shows: ''Series/Supergirl2015'', ''The Flash'', ''Arrow'', and ''Legends of Tomorrow'' by having Barry Allen unite all the heroes he knows to stop an impending invasion from an alien race called the Dominators.
** The 2017 event, ''Series/CrisisOnEarthX'' is even bigger. Whereas ''Invasion!'' was technically only a three part event (with ''Supergirl'' being just a [[RedSkiesCrossover tie-in]] to the main event), this crossover fully plays out over all four episodes, equally juggling the storylines of each show, as well as serving as BackdoorPilot for ''WesternAnimation/FreedomFightersTheRay''. And it actually has lasting repercussions for the Arrowverse's future, as Barry and Iris get married, as do Oliver and Felicity, while Martin Stein is KilledOffForReal.
** The 2018 event, ''Series/Elseworlds2018'', dials things back somewhat, "only" being a crossover between ''The Flash'', ''Arrow'', and ''Supergirl'', though in a surprising twist the [[Series/TheFlash1990 1990 Flash]] ended up making an appearance.[[note]] Legends of Tomorrow was left out for simplicity's sake since ''Crisis on Earth-X'' was a nightmare to coordinate around all four shows' schedule. [[/note]] That said, it is notably a BreatherEpisode compared to the previous year's crossover and is used as a PoorlyDisguisedPilot for ''Series/Batwoman2019''. Ultimately, it is just [[SequelHook a setup]] for the following year's event.
** The 2019-2020 event is ''Series/CrisisOnInfiniteEarths2019'', having been foreshadowed steadily since ''The Flash'' Season 1 and sporadically throughout the other shows, it featured five episodes that span all recurrent Arrowverse series, including ''Supergirl'', ''Batwoman'', ''The Flash'', ''Arrow'', and ''Legends of Tomorrow'' (the last of these actually begins its forthcoming season after the Crisis). A culmination, because this is the last time ''Arrow'' gets to participate, as the show is ending in 2020 and its final season focuses on {{Tonight|SomeoneDies}} TheHeroDies in the lead-up to and the aftermath of the Crisis. It is an adaptation of the classic [[ComicBook/CrisisOnInfiniteEarths comic of the same name]] AKA the TropeNamer. In addition to the return of 1990 Flash, it also features a cavalcade of guest and cameo appearances from other DC live-action adaptations from outside of the Arrowverse continuity, including ''Film/Batman1989'', ''Series/Titans2018'', ''Film/Batman1966'', ''Series/{{Smallville}}'', [[CanonWelding a merger]] of ''Film/SupermanTheMovie'' and ''Film/SupermanReturns''[[note]]The Superman as portrayed by Creator/ChristopherReeve and Creator/BrandonRouth[[/note]], ''Series/BirdsOfPrey2002'', ''Series/Lucifer2016'', ''Series/BlackLightning2018'', ''Series/SwampThing2019'', ''Series/DoomPatrol2019'' and the Franchise/DCExtendedUniverse. It also marks the debut of the titular character of ''Series/Stargirl2020'', [[EarlyBirdCameo ahead of the series' premiere]] in the Creator/DCUniverse streaming service (which includes the aforementioned ''Titans'', ''Doom Patrol'' and ''Swamp Thing'')[[note]]A different version of ComicBook/{{Stargirl|DCComics}} previously appeared in Season 2 of ''Legends of Tomorrow'', played by Creator/SarahGrey[[/note]]. As with the comic book, this crossover has a ''huge'' impact on the franchise, as it ends up merging the ''Black Lightning'' Earth with Earth-38 (the universe where ''Supergirl'' is set) and Earth-1 (where the other four shows are set) into a single new reality.

** ''ComicBook/TheLegendOfTheChaosGod'' is a multi-episode crossover between one and every show of the ''Disney Afternoon'' that was part of the Disney Duck and Mice comic universe. That includes ''[=DuckTales=]'', ''Darkwing Duck'', ''[=TaleSpin=]'', ''Good Troop'' and ''Chip'n'Dale Rescue Ranger'', who were all battling against the vile sorcerer Solego.
** The New Year celebration of year 2000 was the setting for the ''Millenium Orbs'' saga, featuring a crossover between the Mice and Duck comic universes, all battling against evil wizard Euclidus.[[note]]The story was only printed in English in 2007, so the references to the year 2000 were dropped, with Euclidus's backstory moved from 1000 A.C. to the year 1707. The stories generally suffered from it.[[/note]]

* ''Anime/DigimonXrosWarsTheYoungHuntersLeapingThroughTime'' has one in its final few episodes, which saw the return of all the leaders and various other members of all previous Digimon-teams.

* ''ComicBook/SonicTheHedgehogMegaManWorldsCollide'', a large 12-part {{crossover}} flowing through Creator/ArchieComics' three video game licenses: ''ComicBook/MegaMan'' #24-27[[note]]Parts 1, 4, 7 and 10[[/note]], ''[[ComicBook/ArchieComicsSonicTheHedgehog Sonic the Hedgehog]]'' #248-251[[note]]Parts 3, 6, 9 and 12[[/note]], and ''[[ComicBook/ArchieComicsSonicTheHedgehog Sonic Universe]]'' #51-54[[note]]Parts 2, 5, 8 and 11[[/note]]. The gist is that following the ''Sonic Genesis'' arc in the Archie Sonic comics, a Chaos Emerald has landed in the ''Mega Man'' universe, leading to a chance meeting between Doctor Wily and Doctor Eggman as they team up to cosmically conquer their universes. The ramifications are that Mega Man hits the ResetButton on his universe, pushing the crossover to at least after an hypothetical ''VideoGame/MegaMan10'' adaptation in the ''Mega Man'' universe, whereas Eggman inadvertently causes a {{cosmic retcon}}ning of Mobius on a scale the Archie Sonic comics have never faced before in its 20-year history, primarily designed in real life terms to jettison the aftermath of [[ScrewedByTheLawyers the Ken Penders legal case]] on the Sonic comics' narrative without just unceremoniously killing his characters off-screen or invoking WhatHappenedToTheMouse.

* ''VideoGame/FateGrandOrder'' features nearly every Servant, and many non-Servant characters (some now summonable as Servants), from ''VisualNovel/FateStayNight'', ''LightNovel/FateZero'', ''VideoGame/FateExtra'', ''LightNovel/FateApocrypha'', and even ''Anime/FatePrototype'' and ''Manga/FateKaleidLinerPrismaIllya'', in a storyline where the Chaldea Security Organization must fix time anomalies that could destroy the world. There are even characters from non-''Fate'' works such as ''LightNovel/KaraNoKyoukai''.

* The long awaited WarOfTheIndependents mini-series brings together creator-own characters as diverse as ''ComicBook/{{Gumby}}'', ''ComicBook/TheTick'', ''ComicBook/ScudTheDisposableAssassin'', ''ComicBook/{{Cerebus}}'', ''ComicBook/{{Shi}}'', ''ComicBook/{{Bone}}'' and ''ComicBook/HackSlash''. Some of the same characters also appeared previously in the ''ComicBook/{{Normalman}}''/''ComicBook/MegatonMan'' special, ''ComicBook/{{Gen 13}}'' ABC, and Shi / {{Cyblade}}: The Battle for Independents.

* The feature-length special ''WesternAnimation/RudolphAndFrostysChristmasInJuly'' by Creator/{{Rankin Bass|Productions}}, which brought back several characters from all of their holiday specials and many of the voice actors from the previous specials as well. It involves Rudolph, Frosty, and Santa trying to stop an evil wizard named Winterbolt. It also contains a bounty of ContinuityPorn, with callbacks to other previous specials such as ''Santa Clause is Comin' to Town'', ''WesternAnimation/RudolphsShinyNewYear'', and ''Frosty's Winter Wonderland'' (sadly, there are no callbacks to ''The Year Without a Santa Claus'', leaving the poor Miser Brothers snubbed).

** The 2019-2020 event is ''Series/CrisisOnInfiniteEarths2019'', having been foreshadowed steadily since ''The Flash'' Season 1 and sporadically throughout the other shows, it featured five episodes that span all recurrent Arrowverse series, including ''Supergirl'', ''Batwoman'', ''The Flash'', ''Arrow'', and ''Legends of Tomorrow'' (the last of these actually begins its forthcoming season after the Crisis). A culmination, because this is the last time ''Arrow'' gets to participate, as the show is ending in 2020 and its final season focuses on {{Tonight|SomeoneDies}} TheHeroDies in the lead-up to and the aftermath of the Crisis. It is an adaptation of the classic [[ComicBook/CrisisOnInfiniteEarths comic of the same name]] AKA the TropeNamer. In addition to the return of 1990 Flash, it also features a cavalcade of guest and cameo appearances from other DC live-action adaptations from outside of the Arrowverse continuity, including ''Film/Batman1989'', ''Series/Titans2018'', ''Film/Batman1966'', ''Series/{{Smallville}}'', [[CanonWelding a merger]] of ''Film/SupermanTheMovie'' and ''Film/SupermanReturns''[[note]]The Superman as portrayed by Creator/ChristopherReeve and Creator/BrandonRouth[[/note]], ''Series/BirdsOfPrey'', ''Series/Lucifer2016'', ''Series/BlackLightning2018'', ''Series/SwampThing2019'', ''Series/DoomPatrol2019'' and the Franchise/DCExtendedUniverse. It also marks the debut of the titular character of ''Series/Stargirl2020'', [[EarlyBirdCameo ahead of the series' premiere]] in the Creator/DCUniverse streaming service (which includes the aforementioned ''Titans'', ''Doom Patrol'' and ''Swamp Thing'')[[note]]A different version of ComicBook/{{Stargirl|DCComics}} previously appeared in Season 2 of ''Legends of Tomorrow'', played by Creator/SarahGrey[[/note]]. As with the comic book, this crossover has a ''huge'' impact on the franchise, as it ends up merging the ''Black Lightning'' Earth with Earth-38 (the universe where ''Supergirl'' is set) and Earth-1 (where the other four shows are set) into a single new reality.