Sometimes when a series is rebooted or adapted to another medium, the different iterations of the franchise will crossover with each other. This is much more likely to happen in series that are fantasy or sci-fi bent or if the successor doesn't have the same cast.
In particular, when a Long Runner does a crossover with itself, there will usually be so many iterations that it has to narrow down which ones to focus on. Sometimes they focus on the original version which started the franchise, sometimes they focus on the most popular. It could also be some sort of education about the more unknown versions for casual viewers, and can be the most recent version since that's what is producing more money now. Regardless of which, such crossovers usually give equal focus to two or more versions if both are loved and well-known.
The explanation for how such crossovers can happen may vary: the most common is that all the different versions of the same characters exist as part of a Multiverse, and once the characters can jump from one universe to another with the required Phlebotinum, they can meet themselves. Another (similar but more rare) explanation is that all these versions exist in the same universe, but are separated by a time period and so once they have Time Travel, the Super Team from the recent cartoon can meet themselves from the original 1960 cartoon. This can get weird when the old characters aren't meeting their descendants or substitutes, the characters are the same — but thanks to a redesign or a Tone Shift, they will look similar but still different enough to stand apart, and you're expected to believe that the character changed his looks and his personality over time, so, usually, the "new one" doesn't remember being the "old one".
Meet Your Early-Installment Weirdness is common when the two iterations have major differences between each other. See also Crisis Crossover, Bat Family Crossover, The 'Verse and The Multiverse. Compare Spinoff Sendoff, where a new iteration of a franchise is launched with a supporting appearance by someone from the immediately previous version. Sister Trope of Alliance of Alternates, where the crossover happens in the same iteration of the franchise (but overlap between the two tropes is not unheard of). Dream Match Game is a very specific variation found in Fighting Games where (nearly) every playable character in the series up to that point will be brought back for a single installment, usually ignoring continuity in the process. Should not be confused with Intercontinuity Crossover, in which two different franchises clash together.
Examples:
- Digimon:
- Three of Digimon V-Tamer 01's bonus chapters involve Taichi and Zero encountering characters from later Digimon works. Namely, Daisuke and V-Mon from Digimon Adventure 02, Ryo Akiyama and Monodramon from the Wonderswan series and Takuya from Digimon Frontier.
- In the last two episodes of Digimon Xros Wars: The Young Hunters Who Leapt Through Time, the protagonists of the prior seasons of Digimon shows (Taichi and Agumon from Digimon Adventure, Daisuke and V-Mon from Digimon Adventure 02, Takato and Guilmon from Digimon Tamers, Takuya from Digimon Frontier, and Masaru and Agumon from Digimon Data Squad/Savers) arrived to help the heroes against Quartzmon. In addition, Mimi, Palmon, Jou, Gomamon (all from Adventure), and Ruki and Renamon (Tamers) also appear in that set of episodes.
- Super Dragon Ball Heroes is this for Dragon Ball to an extent. Specifically, the Prison Planet saga sees Son Goku from Dragon Ball Super meets Son Goku from Dragon Ball GT. Also, some characters from other media like Ozotto and Slug appear as enemies in the series.
- The seven seasons of Jewelpet take place in alternate continuities, with the main settings and human characters changing each season along with the Jewelpets' personalities. In Episode 21b of Jewelpet: Magical Change, Ruby gets a call from her Jewelpet (2009) self and learns about her human partner Rinko and her search for the Jewelsticks, followed by the Rubys from the remaining five seasons giving the Magical Change Ruby a call as well. This culminates in the Magical Change Ruby somehow calling herself on her Jewel Pod, which the Ruby receiving the call doesn't seem to be confused by.
- Lyrical Nanoha:
- A one-shot made to celebrate the release of Magical Girl Lyrical Nanoha: The Movie 2nd A's featured characters from four separate points in the main continuity's timeline talking with each other about the movie, a direct mention of Gears of Destiny, and a joke involving Magical Girl Lyrical Nanoha INNOCENT.
- Due to time-travel shenanigans, Magical Girl Lyrical Nanoha A's Portable: The Gears of Destiny features an encounter between the protagonists of the Portable continuity (an Alternate Timeline where Reinforce Eins survived the Book of Darkness Incident) and several characters only existing in the Primary continuity (where Eins died), effectively creating a crossover between different, mutually exclusive timelines of the series.
- A drama CD for the game has it cross over with the second movie. Note that the movies are propaganda produced by the TSAB and shouldn't even exist as a separate continuity.
- Pretty Cure has Pretty Cure All Stars, a series of crossover movies that teams up all of the Pretty Cure teams. Each film features Cures from all continuities joining forces to combat a new powerful foe, with focus given to the teams from the currently-airing season and the recently-ended one.
- The comic book Battlestar Galactica vs. Battlestar Galactica is a crossover between the two versions of the show.
- The DCU:
- Of all Crisis Crossovers DC Comics has had in its history, among the most fitted to this trope is Final Crisis, especially when Superman goes into the Multiverse in the Superman Beyond tie-in and meets a lot of his Alternate Selves from parallel universes, with a lot of known Supermen like the Red Son, as well as new versions of him, like Overman (an ex-Nazi Superman) and President Calvin Ellis (basically Barack Obama as the Son of Krypton). All of them work together to stop Darkseid and end the Crisis. It has a spiritual sequel in the Superman (Rebirth) storyline "Multiplicity", with Supermen from across the multiverse being kidnapped by a new enemy.
- Another fitting version of this is Convergence, in which versions of DC characters from virtually every Alternate Universe they published up to that point are forced to fight.
- An earlier form of this happened in Crisis on Infinite Earths, where Superman met his Earth-2 and later Earth-Prime counterparts, which became a major part of the plot of its sequel Infinite Crisis.
- And going even further backward, it all started with "Flash of Two Worlds", in which Earth-1 Flash (Barry Allen) first encountered Earth-2 Flash (Jay Garrick) after Barry accidentally crossed the "vibration barrier" between dimensions. This was just the start of the Crisis Crossover events DC would have across all of its history.
- Issue 13 of the DC Super Hero Girls: Spaced Out digital series features Zatanna showing the Super Hero High students a peek into the universe of the television series that premiered in 2019.
- A case is seen in the events surrounding The Final Days of Superman; the pre-New 52 Superman and Lois Lane have ended up in the New 52 timeline, staying off the radar as they raise their son Jonathan. After the N52 Superman falls in battle against a powerful enemy, the pre-N52 Superman decides to take over for him. At least until much later in Superman Reborn, when the two Supermen and Loises merge with each other.
- There's also The Button and Doomsday Clock which featured the ultimate confrontation between idealism and cynicism; Superman vs. Dr. Manhattan.
- Ghostbusters (IDW Comics): After a crossover with the Teenage Mutant Ninja Turtles taught them how to travel the multiverse, the original Ghostbusters from the 1984 movie encountered those from The Real Ghostbusters cartoon. In a sequel, the crossovers expanded to include the 2016 remake, Extreme Ghostbusters, and several video game versions.
- The Judge Dredd story "Trinity" sees Dredd pulled into an alternate universe, where he has to team up with his counterparts from both movies to catch the perp and return home.
- Spider-Man:
- Spider-Verse is a major example based on the Spider-Man character; promising "Every Spider-Man Ever", it's a comic book arc focused around the many different versions of the hero, joining forces in a quest to fight a villain who wants to wipe out all of them. Along with the multiple Spider-Men from comics, ranging from alternate universes, alternate timelines, alternate identities and other superheroes that also have a spider theme, they also mixed in other Spider-Men from animated and live-action series, manga and video games.
- Among the weirder versions of the character featured in that arc, we find Spider-Man from the corny 60s cartoon, Six-Armed Spider-Man, Spider-Ham, the pig from an alternate universe populated by funny animals, and Takuya Yamashiro AKA Japanese Spider-Man, from the 70s live-action series where he has a giant robot (which he brought to the crossover) as well as both Japanese versions from the manga.
- However, thanks to copyright issues, they couldn't include every version of Spider-Man as promised. In particular, the famous versions from live-action movies couldn't be shown on panel, but one Spider-Man mentions that he saw another one that looks like the guy from Seabiscuit, another movie by Tobey Maguire, and another one mentions one that looks the guy from The Social Network, another movie by Andrew Garfield.
- Also, there's the Spider-Men series (2012 and 2017), in which Miles Morales meets Peter Parker from Earth-616 (before the Secret Wars Crisis Crossover) and learns some classes about how to be Spider-Man. This plot and Spider-Verse were combined to make the 2018 CGI movie Spider-Man: Into the Spider-Verse.
- Transformers: The Transformers Universe comic book was about Unicron abducting Autobots, Maximals, Decepticons and Predacons throughout the multiverse. The later collectors' club comics take an approach more akin to a Cross Through, with fixed protagonists traveling through the many Transformers universes.
- All Assorted Animorphs AUs: "What if they were all from different AUs á la Into the Spider-Verse?" has one Animorph from each official alternate universe being transported to the "prime timeline". Cassie is from book canon, Jake is from #11, Marco is from #41, Rachel is from Megamorphs #3, Ax is from Megamorphs #4, and Tobias is from the TV show.
- Arc Royale is a rare example of a fanfic author doing this with their own fics. In it, the Gods are tired of watching the stalemate between Oz and Salem, and decide it would be more interesting to have the matter settled through a combat of champions. In the supposed interest of fairness, the main combatants are all various incarnations of Jaune Arc (the weakest member of the main cast), each hailing from one of Coeur Al'Aran's many RWBY AU fics and bonded to one of the other characters ala the Fate Series.
- Carefree
is a Sonic the Hedgehog crossover oneshot where SegaSonic canon meets Sonic the Comic canon. Fleetway's Sonic gets stranded on SegaSonic's Earth. He's surprised by how different their Sonic is and how more carefree he seems.
- Dark World Role Play (Deltarune, Undertale): Even though the roleplay takes place mainly in Cyber World, Jevil also has found his way into the world. There are also channels for specific AUs, and channels so that those AUs can interact with each other.
- Scooby-Doo and the Cyber Chase has the early-2000s version of Mystery Inc. meet virtual versions of their 1969 incarnations. Fred and Daphne comment on how their costumes have changed; Shaggy and Velma, who have changed less, not so much.
- Spider-Man: Into the Spider-Verse: Just like in Spider-Verse, the movie is about Spider-Men from different universes landing in the home dimension of Miles Morales, fighting together to defeat the Kingpin and struggling to get back to their own dimensions. Its sequels would flip the script and have Miles team-up with other Spiders by traveling to their dimensions.
- Teen Titans Go! vs. Teen Titans is also this due to being a crossover between Teen Titans (2003) and Teen Titans Go! . It also has Titans from various dimensions helping both teams in the climax with the most notable versions being from the DC Animated Movie Universe, the Tiny Titans comics and even The New Teen Titans comics which the 2003 show was based on.
- Turtles Forever is a textbook example, with the Teenage Mutant Ninja Turtles from the 2003 animated series meeting up with the Turtles from the 1987 animated series. The two versions of the Turtles exist in alternate dimensions and meet each other when messing with interdimensional travel. In the end, both versions meet the original Turtles from the 1984 comic books, who are presented as the prime Turtles. Erasing the existence of the 1984 Turtles would do the same to all the other versions. Also, a computer screen shows the Multiverse, which features the many dimensions populated by other versions of the Turtles like the 2007 CGI movie, the live-action movies from the '90s, and even the bizarre two-episode anime. However, missing from the screen are some Old Shames like the live-action TV series and the rock musical.
- Spider-Man: No Way Home: This film ended up being a crossover between every live-action movie iteration of Spider-Man to ever appear, where Peter Parker accidentally causes Doctor Strange to open up The Multiverse, causing villains from the previous Spider-Man films to enter the MCU. These include from Sam Raimi's Spider-Man Trilogy: Green Goblin, Doctor Octopus, and Sandman; and from The Amazing Spider-Man Series: Lizard and Electro. And then the Spider-Men from those movies themselves show up to allow for an Alliance of Alternates! What's more, all of the original actors reprise their roles.
- Tokumei Sentai Gobusters Returns Vs Dobutsu Sentai Gobusters revolves around an alliance between the main universe's Tokumei Sentai Go-Busters and the Denser and Wackier Dobutsu Sentai Go-Busters from an alternate universe to stop a villain, whose victory led to the creation of the second universe.
- The 2019 Arrowverse Crisis Crossover, Crisis on Infinite Earths (2019), features cameos from many different versions of characters from throughout DC media, with some of them being alternate versions of each other. These include the Supergirl Clark Kent meeting the Smallville Clark Kent and later the Clark Kent from Superman Returns. Meanwhile, Barry Allen from Earth-1 (The Flash (2014)) meets his Earth-90 counterpart (The Flash (1990)) along with the version from the DC Extended Universe.
- Doctor Who:
- The Multi-Doctor specials, where different versions of the Doctor will team up to face a common threat. More applicable to specials where the Doctor from the New Series teams up with one from the Classic Series (starting with the special "Time Crash"), such as "The Day of the Doctor" and "Twice Upon a Time".
- There was also the big Torchwood/Sarah Jane crossover for The Stolen Earth/Journey's End two parter on the parent show.
- David Brent, the hopeless boss from the British version of The Office, made a couple of guest appearances on the American version, even meeting his US counterpart Michael Scott.
- Power Rangers:
- Following the example of Super Sentai below, the series has various episodes when Rangers from previous seasons (usually called as "Retro Rangers" and "Legendary Rangers"), made mostly for Anniversary Specials of the series. The yearly tradition similar to Sentai's sadly came to an end during the Disney era, as such episodes were deemed too expensive, especially without toys to promote (the returning team being off the toy shelves by this point.
- The 10th Anniversary Special has the "Forever Red" episode in Power Rangers Wild Force, in which Red Lion Ranger teams up with all the previous Red Rangers from past nine seasons, including Jason David Frank as Zeo Ranger V Red.
- The 15th Anniversary Special has the "Once a Ranger" double episode, in which the Rangers of Power Rangers Operation Overdrive get replaced temporarily by (and teams up with) the team called as the "Retro Rangers
", formed by Black Ranger (Adam Park, The Leader), Blue Wind Ranger, Yellow Dino Ranger, S.P.D. Red Ranger and Green Mystic Ranger.
- The 20th Anniversary Special has "Legendary Battle" as the Season Finale of Power Rangers Super Megaforce in which appear every Ranger incarnation ever made in Power Rangers franchise. Also, there's "The Legendary Battle: Extended Edition"
which apart of this episode, includes the previous one that starts everything ("The Wrath") and also 43% of extra footage, all of this packed as a DVD movie.
- The 25th anniversary gives us "Dimensions in Danger", with a villain trying to invade The Multiverse (since RPM takes place in an alternate Bad Future and Dino Charge alters history pretty drastically in its final arc, alternate universes are the excuse that lets them join in team-up occasions alongside teams in the normal universe). The main returning Rangers are Tommy, Wes, Gemma, and Koda, each representing one of the four past eras of the franchise, with Katherine, TJ, Rocky, Antonio, Gia, and Trent joining in the final battle.
- Super Sentai:
- The series traditionally had a team up with their previous counterparts from the previous seasons. The former does this as a late season team up movie, while the later does this as an episode that adapts footage from the movie. The Super Sentai movies also feature a quick sequence that marks the first debut of the upcoming season.
- Special mention goes to Kaizoku Sentai Gokaiger, which features an appearance by one member of every team from all previous 34 incarnations.
- Recently, the series has begun featuring team ups of teams from various teams with similar themes. Zyuden Sentai Kyoryuger vs. Go-Busters featured team ups with the previous two dinosaur teams (Kyōryū Sentai Zyuranger and Bakuryuu Sentai Abaranger plus the Cameo from Ressha Sentai Toqger). Shuriken Sentai Ninninger featured the return of the respected red rangers from Ninja Sentai Kakuranger and Ninpuu Sentai Hurricaneger and a cameo from the red ranger of Himitsu Sentai Gorenger to commemorate the 40 year-to-the-day anniversary of the first episode of Super Sentai.
- In one strip of the Pleasant Goat and Big Big Wolf manhua, Wolffy in his Mr. Wolffy, Mr. Right! design meets Sparky and Weslie in their designs from the normal show. Wolffy doesn't stick around for very long.
- Warhammer Fantasy and Warhammer 40,000 are no longer the same franchise, but because there are several common elements (chiefly the Chaos gods), some of their units can be used interchangeably between games.
- The Liber Chaotica is an in-universe book written by a (Fantasy) Imperial scholar on Chaos daemons, with one section on 40K daemon engines related faithfully despite his utter lack of comprehension at what's going on.
- Some extremely destructive weapons can occasionally be found in the Chaos Wastes (a Grim Up North place where the Warp intersects with reality) that can be recognized as 40K weapons such as power swords and plasma guns.
- If it's a Bomberman work, chances are Power Bomberman has represented it in some way, mainly through characters. It doesn't just limit itself to the main series of games, either, as it also takes from the spin-offs, cancelled titles, the various manga, the two anime series (Bomberman B-Daman Bakugaiden and Bomberman Jetters), and even promo art.
- Castlevania: Judgment: The character Galamoth plots to send the Time Reaper from 10,000 years in the future into the past to destroy his rival Dracula and change history. A man named Aeon discovers this and pulls together champions from different eras of history into a time rift, in order to find a chosen one capable of destroying Galamoth's servant, the Time Reaper.
- Fate Series:
- Fate/Grand Order pulls from all over the Fate series, including its alternate universes (Prototype and the universe Musashi comes from, for starters), offshoot timelines (Hollow Ataraxia, EXTRA), and even its gag series (Koha-Ace and Learning with Manga!). Unfortunately, not everyone could make it to the game, as most of the cast of strange fake is on embargo until it wraps up.
- Grand Order incorporates the greater Nasuverse even outside the Fate subseries; one of the first "collaboration" events of the game was with The Garden of Sinners.
- For Fire Emblem, there were two attempts to make a crossover from all over the franchise in 2017. One was a Musou-styled game featuring characters from Archanea, Ylisse, Hoshido, and Nohr along with two girls from Valentia and Elibe respectively and a few Original Generation people. The other was a gacha that has a more complex variety of characters, not only adding units from the previously mentioned worlds, but also from other worlds like Jugdral, Magvel, Tellius, Fódlan, Elyos, and even freaking Tokyo. This concept was revisited again in Engage nearly six years later, and this time at least one character from each mainline game released up to this point take the form of spirits known as "Emblems" that inhabit rings or bracelets that fight alongside characters original to the game, while a vast majority appear as bond rings, with the added bonus that the "crossover" bit plays a major role in the game's plot.
- While many Gundam games are adaptations of a single work or serve as What If?/Expanded Universe material, several others are more traditional Crisis Crossovers between the various timelines, often with an Excuse Plot thrown in. Examples include the first Gundam Battle Assaultnote , the Gundam Vs Series starting from Gundam vs Gundam and Dynasty Warriors: Gundam.
- The Legend of Zelda: In Hyrule Warriors, all the playable characters in the base game of the original Wii U version that aren't legacy characters or original come from the Adult Link games: Ocarina of Time (original and popular), Twilight Princess (popular) and Skyward Sword (modern). There's also an entire mode dedicated to the original NES The Legend of Zelda. Eventually, through DLC and updated versions such as Hyrule Warriors Legends on the 3DS, characters from other Zelda games were added to this game, including ones from Majora's Mask, The Wind Waker, Link's Awakening, Phantom Hourglass/Spirit Tracks and A Link Between Worlds.
- Mario & Luigi: Paper Jam is an installment from the Mario & Luigi series where characters from the Super Mario Bros. games meet their paper counterparts.
- This is commonly seen in the Mega Man series:
- In some other media apart of video games, this is commonly seen when Mega Man meets X, like in an episode of the Ruby-Spears American cartoon and in one of the Mega Man (Archie Comics) comics.
- In Mega Man II, there's Quint, a Mega Man from the future who was brought to the present and modified by Dr. Wily to be one of "Mega Man Killers", who also returns in future games of the Classic franchise.
- Also seen in various of Capcom vs. games in which various Mega Man versions (or characters from different game series) can be seen together, like SNK vs. Capcom: Card Fighters Clash series in which you can see Character Cards of all Mega Man games in the same deck. Another good example is Tatsunoko vs. Capcom, in which Rock Volnutt is present alongside Roll (and, in Ultimate All-Stars, Zero) despite the wide gaps in time between their respective series.
- Rockman.EXE Operate Shooting Star is a Japan-only Nintendo DS remake of the first Mega Man Battle Network with an added chapter in which Geo Stelar of Mega Man Star Force travels back in time and teams up with his predecessors.
- A literal example is seen in Super Smash Bros. for Nintendo 3DS and Wii U, in which the original Mega Man is a Guest Fighter, and his Final Smash is a Combination Attack in which various other Blue Bombers (X, Rock Volnutt, MegaMan.EXE and Mega Man/Omega-Xis) appear alongside him to fire a joint Charge Shot together. This was retained for the next game in the series, Super Smash Bros. Ultimate, only with the addition of Proto Man and Bass from the Classic series.
- Commonly seen in M.U.G.E.N, in which you can make the roster as you like, so you can put the same character from different games in the same created fighting game you like. As example, you can put Ryu from Street Fighter II, Street Fighter Alpha, the Marvel vs. Capcom series, the Capcom vs. SNK series, SNK vs. Capcom: SVC Chaos, and even the original Street Fighter in the same roster and make them fight against each other.
- Persona:
- Persona 4: Arena is a Fighting Game sequel to the events of Persona 4 wherein the Investigation Team crosses paths with a few former members of S.E.E.S. (Mitsuru, Akihiko, and Aigis), now calling themselves the Shadow Operatives, as well as Elizabeth, the third game's Velvet Room attendant. Where this trope really kicks in is the sequel, Persona 4: Arena Ultimax, which sees not only the majority of the other Persona 3 party members return to action (though Fuuka remains on the sidelines, unlike fellow Support Party Member Rise), but several NPCs from Persona 4 (Golden) get Promoted to Playable, accounting for most of the still living major players in P3 and P4. And even then, it turns out that Ikutsuki, the Mole in Charge for S.E.E.S., is responsible for one of the main antagonists and gets several fakes in his likeness to cameo throughout Ultimax despite being confirmed dead. Unlike the Persona Q titles below, this duology is canon.
- Persona Q: Shadow of the Labyrinth is a non-canon game featuring the playable characters from Persona 3 and Persona 4. Oddly, despite the original games being only a few years apart in places so close that characters from 4 have visited the setting of 3, this game still had to resort to Timey-Wimey shenanigans due to the protagonist's death at the end of Persona 3. Once the Reality-Breaking Paradox that brought both groups together is dealt with, they return home without any knowledge of what happened, hence why no one recognizes each other during the events of Persona 4: Arena.
- Its sequel, Persona Q2: New Cinema Labyrinth, reunites the P3 and P4 casts on top of bringing in the Phantom Thieves of Hearts and the female protagonist exclusive to Persona 3 Portable (who is implied to be an Alternate Self to her mainline counterpart). While the same Timey-Wimey shenanigans ensue once again to get around the P3 protagonist's canonical death (as well as the fact that P5 is at least a few years farther along in the timeline than P4 was), Joker, the Player Character of 5 and Q2, appears to be the only person outside of the Velvet Room attendants to exhibit Ripple-Effect-Proof Memory after returning to his time, as he recognizes Hikari while attending a high school film festival in the epilogue.
- Pokémon: The "core" games are generally treated as one continuity, the long-running Pokémon anime another, and each "spinoff" game its own separate pocket universe. This doesn't stop the anime from periodically passing through other continuities, though:
- Pokémon Red and Blue: Despite being a canon game, the third of the trio, Special Yellow Pikachu Edition, uses the anime designs instead of the ones from Red and Blue/Green. This includes replacing the generic Team Rocket grunts with Jessie and James (and Meowth). The main character is locked into a Pikachu as a starter instead of being able to choose from Bulbasaur/Charmander/Squirtle (but later can obtain them anyway), like Ash did in the anime, and starting off the rival with Eevee, just like Gary did.
- Pokémon Sun and Moon: Special "Ash's Cap" Pikachus were given out for the 20th anniversary of the franchise, as well as for a tie-in with the I Choose You! movie. Meanwhile, a Greninja with the Ash-Greninja ability from the anime was given out as a thank-you for playing the game's demo. These Pokémon also showed up in Pokémon Shuffle and Tretta.
- Power Rangers: Battle for the Grid features a host of characters from across the franchise (including a villain from the comic book adaptation that had never appeared in the series proper).
- Sonic the Hedgehog:
- Sonic Generations:
- The game features the modern Sonic from the Dreamcast era, who was redesigned with green eyes, longer legs and smaller belly, meeting through time travel the classic Sonic from the Genesis/Mega Drive era, who is pudgy, has black eyes and short legs, and also never talks.
- The gameplay is divided between the two characters, the Classic Sonic levels are played just like the Genesis 2D platformers but with 3D graphics, while the Modern Sonic levels are similar to Sonic Unleashed, having 3D gameplay but some 2D sections, but in those 2D sections, Modern Sonic can use moves that his classic counterpart can't.
- The game features levels based on all main series games, dividing them up into three categories, Classic (Genesis/Mega Drive era), Dreamcast (which includes Sonic Heroes) and Modern (Sonic '06 and onward). Back are iconic level themes like Green Hill Zone and Chemical Plant Zone, and also modern levels like City Escape and Seaside Hill, and all levels are divided in two parts for the two characters, modern levels and their gimmicks are adapted for the pure 2D classic gameplay, and classic levels are adapted with gimmicks from the 3D games for the modern gameplay.
- Each Era has its own boss fights too, there is the final boss of Sonic the Hedgehog 2 fought by Classic Sonic, and Perfect Chaos (Sonic Adventure) and Egg Dragoon (Sonic Unleashed) fought by Modern Sonic, the 3DS version has different bosses, and there's also rival battles, with Metal Sonic being the first and fought by Classic Sonic, Shadow and Silver being the second and third and fought by Modern Sonic.
- The Final Boss is both Classic and Modern Sonic uniting themselves and using the Chaos Emeralds to fight the Time Eater, controlled by Modern Dr. Eggman and Classic Dr. Eggman, the latter of which is called Dr. Robotnik by Classic Tails, prompting him to point out no one calls him that anymore.
- Classic Sonic and Modern Sonic once again team up in the sequel game Sonic Forces, the other part of the 25th anniversary celebration of the franchise, in which the player can choose between three different styles, Classic Sonic style, Modern Sonic style and an Avatar style, a mode in which the player can create their own character. However, Forces retcons Generations by stating that Classic Sonic is not Sonic from the past, and is instead another Sonic from another dimension (presumably because the events of Generations created an Alternate Timeline that branched off from Sonic 3 & Knuckles, leading to Mania for Classic Sonic), something fans weren't pleased to learn.
- Sonic Generations:
- Spider-Man:
- Spider-Man: Shattered Dimensions, a game in which you can manage Spider-Men from different alternate realities, the mainstream one (Peter Parker), Noir one (also Peter Parker), Marvel 2099 one (Miguel O'Hara) and Ultimate one (Peter Parker once again), to find a shattered cosmic MacGuffin and stop their respective villains from using the pieces to become immensely powerful.
- There was a follow-up called Spider-Man: Edge of Time, although this one was only about the mainstream one and the Marvel 2099 one working together to prevent the death of the former from happening, which somehow caused Alchemax from the Marvel 2099 reality to Take Over the World.
- The Super Smash Bros. series is about multiple franchises crossing over, but some examples fit the trope:
- Just like in Hyrule Warriors, the The Legend of Zelda franchise has multiple characters from different eras. In Smash 64 and Melee, Link, Zelda, Sheik, Young Link and Ganondorf are based on their Ocarina of Time designs. Brawl and 3DS/Wii U change them to their Twilight Princess designs, but Young Link is replaced with Toon Link from The Wind Waker. Ultimate embraced the multiple eras, as Link has his Breath of the Wild design (with Sheik having a Breath of the Wild-based design, despite not being in that game), Ganondorf and Young Link use their N64 designs, Zelda has a design based on A Link to the Past and A Link Between Worlds, while Toon Link of course represents The Wind Waker again. The series also has many Assist Trophies, stages and music from different Zelda games that don't have a playable fighter.
- Fire Emblem has multiple playable protagonists from across the series in the roster; for its debut in Melee, Marth from Shadow Dragon and Roy from The Binding Blade were implemented as newcomers. Brawl would drop Roy, but keep Marth and bring in Ike from Path of Radiance and Radiant Dawn. The next instalment, for 3DS/Wii U, would bring back Marth and Ike while adding Robin and Lucina from Awakening, then reintroduce Roy as DLC and also bring in Corrin from Fates as one of the last downloadable fighters. Ultimate would bring all of them back, while also introducing Chrom from Awakening in the base game and Byleth from Three Houses as DLC. Like Zelda above, it also has secondary content from other games without a fighter.
- The only playable character from the Mega Man franchise is Mega Man from the Classic series, but his Final Smash features X from Mega Man X, MegaMan Volnutt from Mega Man Legends, MegaMan.EXE from Mega Man Battle Network, and Star Force Mega Man from Mega Man Star Force. Ultimate added Proto Man and Bass to said Final Smash, and the game also has Zero from Mega Man X as an Assist Trophy.
- For Castlevania, Ultimate introduced both Simon Belmont, from the original game in the series, and Richter Belmont, from Rondo of Blood, as playable fighters, with Alucard also appearing as an Assist Trophy deliberately designed after his Symphony of the Night incarnation. Likewise, there's various music tracks and Spirits of characters from multiple games in the series.
- The Dragon Quest franchise has four different heroes from four different games in one fighter slot: Luminary from Dragon Quest XI, Erdrick from Dragon Quest III, Solo from Dragon Quest IV and Eight from Dragon Quest VIII. Luminary is the main character, and the other three work as alternate costumes.
- Subverted with Xenoblade Chronicles. While the first game and 2 can be enjoyed as standalone adventures and the representatives from each on Smash (Shulk for the first game and Pyra/Mythra for 2) don't meet each other canonically in the series proper (they do get crossover DLC in 2), the big twist of 2 is that their respective worlds were split apart from each other and that their adventures are happening simultaneously. Not only that, but Xenoblade Chronicles 3 drops all pretenses of this being a spoiler of any kind by explicitly being set in the future of both worlds and having characters from both meet each other, albeit not Shulk and Pyra/Mythra.
- The Alvin and the Chipmunks episode spoofing Back to the Future has the 1980s Chipmunks meeting their 1960s counterparts from The Alvin Show.
- The final episode of Ben 10 (2016) was Alien X-Tinction, a one-hour special that had Ben team up with the all the differently-aged versions of himself from the "Classic" continuity, as well as the version of Gwen who got the Transformation Trinket instead.
- An In-Universe example happens in The Fairly OddParents!. In the episode "The Crimson Chin meets Mighty Mom and Dyno Dad", the Crimson Chin meets several wildly different versions of his Era-Specific Personality, from the '30s pulp-fiction Chin, to the "super-edgy" 1985 Chin, who got cancelled for swearing.
- The Justice League episode "Legends" was initially intended to feature the Justice Society of America. The rights weren't cleared (possibly because the superheroes involved were portrayed as somewhat bigoted), so the writers instead used a Captain Ersatz version called "The Justice Guild".
- The Simpsons:
- In one version of the Couch Gag, the Simpsons run in and find the original versions of themselves already sitting there.
- In "The Day the Violence Died", the day is saved by Lester and Eliza, who are basically the Bart and Lisa from The Tracey Ullman Show shorts.
- In the thirteenth Treehouse of Horror episode, Homer makes clones of himself during the segment "Send in the Clones". After the clones cause trouble, Homer attempts to abandon them and the hammock that created them, but the clones just use the hammock to create even more clones; one of the degraded clones looks like Homer from the early Tracey Ullman Show shorts, who says "Let's all go out for some frosty chocolate milkshakes!"
- In a later Treehouse of Horror segment (XXV's "The Others"), the Simpsons are haunted by the ghosts of the Tracey Ullman-era Simpsons. The ending of that segment featured various derivatives of the family wanting to move into the Modern Simpsons' house after they were killed. Most of the alternate Simpsons were created specifically for this scene, but three previous versions do make an appearance here — the "Island of Dr. Hibbert" ("Treehouse of Horror XIII") Simpsons in their animal forms (Panther Marge, Spider Bart, Aardvark Maggie, Owl Lisa, and Walrus Homer), the LEGO Simpsons from "Brick Like Me", and Sylvain Chomet's version of the Simpsons from "Diggs"' Couch Gag.
- Spider-Man:
- Spider-Man: The Animated Series has the "Spider Wars", which (along with the later Spider-Man: Shattered Dimensions, mentioned in the Video Games section) actually inspired the Spider-Verse comic book storyline. Here, Madame Web (and later the Beyonder) first recruited Spider-Man from the main universe of the series and later recruited various alternate versions of him, including Armored Spider-Man
(a kind of "Tony Stark" version of Peter Parker), Six-Armed Spider-Man (a mutated version of him that permanently has six arms, seen in comics and the same series but Gone Horribly Wrong), Spider-Man with Doctor Octopus' arms (predating Superior Spider-Man by decades), Spider-Man as an actor, and even the Scarlet Spider (Ben Reilly as in The Clone Saga). This group is simply named the Spider-Men
.
- Ultimate Spider-Man (2012) did its third season serve as this, having Peter interact with Noir, Spider-Ham, 2099, Spyder-Knight, Spider-Girl (in this case, a Gender Flip version of him named Petra Parker), and Miles Morales (who made his animated debut with this show). It even got a sequel in which the obscure Blood-Spider and Spider-Gwen (likewise making her animated debut here) got to join the fun.
- Spider-Man: The Animated Series has the "Spider Wars", which (along with the later Spider-Man: Shattered Dimensions, mentioned in the Video Games section) actually inspired the Spider-Verse comic book storyline. Here, Madame Web (and later the Beyonder) first recruited Spider-Man from the main universe of the series and later recruited various alternate versions of him, including Armored Spider-Man
- Teenage Mutant Ninja Turtles (2012) did something similar to Turtles Forever, with an episode crossing over with the 1987 cartoon with a plot similar to Turtles Forever. Since the 1987 cartoon was hand-drawn but the 2012 cartoon was CGI, the episode uses Art Shift, alternating between hand-drawn animation and CGI depending on which universe the scene takes place, and converting the look of the Turtles in the process. For some reason, 1987 and 2012 Donatello stay in their original 2D and 3D forms when they enter the 1984 comic universe, even having colors when the whole comic book world is black and white.