Ret Canon

If an adaptation of a series is popular, it will leave its stamp on subsequent adaptations. More strangely, a popular adaptation may leave its stamp on the series it was adapted from, if that series is still ongoing.

For the more general application of changes to the work, see Retcon.

The Canon Immigrant is often a walking example of Ret Canon. See also: Adaptation Displacement and Canon Discontinuity.

Anime & Manga

 * Shortly after the Negima alternate universe adaptation introduced Armor Nodoka's ability to split her Diarium Ejus up to read multiple minds, the Nodoka of the manga gained this ability as well (though her version actually shrinks the books based on how many splits she's used).
 * Dragon Ball: Akira Toriyama was so impressed with the TV special featuring Goku's father Bardock that he subsequently incorporated the character into the manga for a two-panel flashback to the ending of the special, earning both him and the special canon status. This makes Bardock the only anime-original character to be featured in the manga.

Comic Books

 * In The DCU:
 * Batman's Battle Butler Alfred was originally drawn as a stout and clean-shaven man, but in 1944 he was dispatched to a health resort from which he would return thin and mustached so that he would resemble William Austin's portrayal in the 1943 serial. So this is Older Than Television.
 * Also, he originally died in the comics but the 60's Adam West series got him revived.
 * It was Marlon Brando's idea to have Jor-El wearing a recognizable 'S' logo in the 1978 Superman film, making it a preexisting Kryptonian emblem rather than merely a personal symbol of Superman. This change filtered into the comics awareness, explicitly finalized in the 2003 title Superman: Birthright.
 * Another DC comic story, "The Sword of Superman" had an ancient, cosmic sword implant the idea into Martha Kent's head to sew the S symbol, the same one depicted on the sword's hilt, onto the Superboy costume.
 * It also inspired Jor-El and Lara to name their son Kal-El (meaning "Star Child" in ancient Kryptonese).
 * The childhood of Clark Kent was changed once in response to the Movie with his powers developing gradually and no career as Superboy, and more recently it has changed again to become closer to the portrayal in Smallville, including restoring Lex Luthor as a Smallville resident and friend of Clark (which, ironically, is what they had changed him from Post-Crisis).
 * His career as Superboy was a retcon in itself. The original telling of Superman's origin in Action Comics #1 had him raised in an orphanage, and his super powers developing slowly during adolescence.
 * Indeed, the whole cold, antiseptic look of the Post-Crisis Krypton was taken from the movie. Ironically, Superman: Birthright undid this change, moving it back toward the Silver Age version.
 * Post-Infinite Crisis, Krypton is even more like the movie version than it was post-Crisis. Superman's fortress is now the same crystalline structure seen in the films (and in Smallville), complete with Jor-El hologram.
 * Also, after the movie, many artists drew Superman resembling Christopher Reeve.
 * With John Byrne being the first, because he couldn't follow the style of Curt Swan.
 * In both the Golden and Silver Age, Wonder Woman had the magic lasso—which could compel total obedience from anyone caught in it. As one might imagine, she had it used on her pretty regularly. As this was regarded as a little squicky for television, the lasso's ability to compel was reduced to being able to force its captive to tell the truth. This is now so canon, The Other Wiki doesn't even mention the original ability.
 * More recently, Wondie has started spinning around to change her clothes, a magical transformation used in the 1970's TV show, but not in the comics until twenty years later, when Promoted Fanboy Phil Jimenez was writing & drawing the book.
 * After 2001's Justice League cartoon featured a Hawkgirl as a member, writer Joe Kelly chose to add the DC Universe's then-current Hawkgirl to the contemporary JLA (even though this was a different character, connected to the Golden Age Hawkgirl rather than the Silver Age version from which the cartoon's heroine was adapted).
 * Justice League also introduced the idea that John Stewart (Green Lantern) was an ex- Marine, an idea that's since filtered into the comics.
 * John Stewart also returned to being an active Green Lantern and joined the League during Kelly's JLA run and started wearing the same costume he wore on Justice League (sans gloves) and the same haircut the animated Stewart had in the first two seasons.
 * While John Stewart has yet to sport the "bald with goatee" look from the Unlimited seasons, Power Ring does sport a similar one, thanks in part to the events of JLA-Avengers destroying and rebuilding the Crime Syndicate's universe, giving him a Race Lift that changed him from a blonde Kyle Rayner counterpart into a counterpart for Stewart. Also after joining the post-Infinite Crisis incarnation of the League, John joked about Black Lightning's current bald look, then said he'd looked look good bald with a goatee.
 * The Teen Titans cartoon debuted in the same month as a relaunch of the Teen Titans comic series. Both took inspiration from the classic 80s Marv Wolfman/George Perez "New Teen Titans" series, but it was also pretty obvious that DC was making their properties look similar across the board.
 * The cartoon team was composed of Robin, Starfire, Cyborg, Raven and Beast Boy. The comics team was composed of former Young Justice members Robin, Superboy, Wonder Girl, and Kid Flash, with the 80s Titans Starfire, Cyborg, Raven and Beast Boy returning. The comics team thus superficially resembled the cartoon team - only with the former Young Justice members, most notably Robin, being Legacy Characters of the 80s Titans. At least some of the older Titans were not even teenagers by this point, having aged into their 20s. Notably, comics Raven, in spirit form before the relaunch, was given a new teenage body just for the series, and Gar Logan's codename, then Changeling, reverted to Beast Boy (despite being more like Beast Man).
 * Many of the characters in the cartoon saw their comic versions' costumes get redone to match (or at least more resemble) their animated counterparts. Even Starfire (whose ultra-Stripperiffic bikini-like "armor" isn't going anywhere anytime soon) has her boots changed to resemble series Star.
 * The romantic subtext between Raven and Beast Boy in the cartoon made it into the comics in a bona fide Squee moment. The author claims he didn't do this because of the show, though.
 * Also, many of the characters in the cartoon saw their comic versions' costumes get redone to match (or at least more resemble) their animated counterparts. Even Starfire (whose ultra-Stripperiffic bikini-like "armor" isn't going anywhere anytime soon) has her boots changed to resemble series Star.
 * Ever since Batman the Animated Series redefined Mr. Freeze as a tragic figure, consumed for the lost love of his stricken wife, the original comic version was changed to resemble that.
 * It is, in fact, difficult to impossible to find a web site that actually describes "Mister Zero's" original backstory—if he had one.
 * Yeah, he didn't. He was just a villain with a gimmicky weapon, a lot closer to the version that appeared in The Batman.
 * Based on the popularity of the animated series version of the Clock King (Temple Fugate), a new Clock King with the same name, dress and Awesomeness By Analysis powers (though with a rather sadistic personality) was introduced to The DCU.
 * The series also went with the "Batgirl" moniker to make Barbara Gordon (currently Oracle in comics) begin using that identity as a student rather than a librarian as it originally was, and given this change in age, she got a flirting relationship with Robin (Dick Grayson, now Nightwing in comics). Now flashbacks tend to show Barbara getting her batgirl identity at her teens, and having an on-off relationship with Nightwing (who, before that, was mostly interested on his Titans teammate Starfire, so Ship-to-Ship Combat abounds).
 * Superman flies because the Fleischer cartoons found it easier to animate flight than jumping.
 * Simultaneously, the radio show started depicting Superman flying so that they could fit plot exposition into scenes while he traveled place to place. However, the radio show avoided calling it flight.
 * Most of his other powers came from the radio or cartoon shows, too. Initially, he was just as the opening sequence described him: faster than a speeding bullet, more powerful than a locomotive, and able to leap tall buildings in a single bound. Heat vision, super breath, and more were largely later additions.
 * Action Comics (DC) itself also gradually drifted toward flight due to artist mistakes. As artists depicted Superman performing more and more impossible maneuvers in midair, AC writers explained it away as his ability to change trajectory in midair. When Fleischer, who had followed the comics and radio show, asked point-blank if Superman could fly, AC gave up and said he could. It didn't become official though until a 1942 Superman novel written by the head writer of the radio show, where it explicitly stated Superman flew across the Atlantic ocean to stop a Nazi rocket missile. By 1943, Superman could fly 8 times the speed of light.
 * Superman's childhood home Smallville was apparently just as vaguely located as Metropolis, until the 1978 movie set it in Kansas.
 * Though General Zod already existed in the comics before and after Superman II, his backstory became such a mess that eventually DC decided to make a "definitive" reboot of the character based on his most iconic version: that of the aforementioned film.
 * Kryptonite was first introduced on the Superman radio show in 1943, before being incorporated into the comic book.
 * Before the radio show, there was a proposed story called "The K-Metal from Krypton". It involves Superman dealing with an element called "K-Metal", a precursor to Kryptonite. But this was scrapped since it would change the Status Quo Is God drastically (which included Lois discovering Clark is Superman).
 * When The Flash got a TV series, a couple of small changes were made in the comic: Wally got a dog and a new costume with a symmetric belt like the one on the show. This was only fair since the TV Flash, while based primarily on Barry Allen, also borrowed elements from Wally (such as his post-Crisis need for huge amounts of food).
 * Despite Superman: The Animated Series's version of Supergirl being Kara In-Ze, a loose adaptation of Kara Zor-El, the then-current Supergirl in the comics, Linda Danvers was given the Supergirl costume used in the series.
 * The New Batman Adventures, the sequel show to Batman the Animated Series featured revamped designs for just about every character, in order to streamline the show's look to make it easier to animate on the smaller budget, as well as to make it more compatible stylistically with Superman: The Animated Series. Most of the new designs were poorly received (especially the Joker's), but one in particular that most people seem to like is Scarecrow's. It didn't look much like an actual Scarecrow (more like a western preacher), but it was pretty creepy (which is good considering fear is the Scarecrow's whole shtick). The staff liked the outcome, particularly since they'd fiddled around with different designs before and found them ineffective. Since TNBA, many versions of Scarecrow incorporate that version's distinctive hanged man's noose.
 * Two more from The New Batman Adventures. Between the end of "No Man's Land" and the end of the events of "The Return of Bruce Wayne", Batman had returned to using the original/"Year One" costume, which was what the costume he wore in TNBA (and Justice League) was based on. Likewise, after the "One Year Later" Time Skip after Infinite Crisis, Tim Drake donned a tweaked version of the costume he wore during TNBA.
 * In the New 52, Amanda Waller is a lot slimmer, ala her appearance in the Green Lantern movie, Commissioner Gordon had reddish-brown hair, ala his appearance in The Dark Knight Saga, Bane has a look reminiscent of the Batman: Arkham series, and Etta Candy got a Race Lift ala her counterpart in the failed Wonder Woman pilot and is now African-American.
 * In the Marvel Universe:
 * Following the success of the X-Men movie in 2000, the characters in the comics switched to dark leather costumes which more closely resembled those of the movie. Toad's markedly different appearance and advanced powers (a mostly regular-looking guy with a prehensile tongue and amazing acrobatic skills as opposed to a deformed hunchback who just jumps around a bit) was also copied in.
 * As a minor example of this, Rogue used to have her white streak reach, skunk-like, across her head from front to back. Ever since the movies, only her front bangs have been white (even in X-Men Forever, where her original hair style, at least at first, should have been retained).
 * Of course, the writers can't even decide whether Rogue's hair is naturally like that, or, as mentioned in an '80s letter column bleached by her for effect...
 * The leather costumes only lasted until 2004, when they returned to more traditional superhero costumes.
 * Rogue also lost her curls in favor of straight long hair similar to Anna Paquin's.
 * Gregg Rucka and other artists showed Wolveirne's claws coming from between his fingers as opposed to the backs of his knuckles. Also, like the Superman example, some artists have drawn Wolverine looking like Hugh Jackman.
 * Circa 2005, Spider-Man gained biological webshooting powers like those portrayed in his eponymous 2002 movie. Continuing the trend, in 2007, the "Back in Black" storyline, wherein Spidey starts wearing the black costume again, echoes Spider-man 3, which is a retelling of the original black costume storyline.
 * Peter David, however, will take any opportunity to point out that he introduced organic webshooters to the Spider-man mythos with Spider-man 2099.
 * Technically, Stan Lee was the first person to do that since he originally wanted to have Spider-Man shoot webs but thought it would seem repulsive to 60's audiences. He ended up turning him into a science whiz instead. Also, Venom's symbiote spun organic webs so the concept has been present in the spider-mythos long before Spidey 2099.
 * The supervillain Bullseye originally wore a costume with a mask that had a bullseye design on it. In the 2003 Daredevil movie, Bullseye dressed like a biker and had a bullseye scar directly on his forehead. Sometime later the comic book version received the scar as well, when an enraged Daredevil carved a bullseye into the forehead of his nemesis.
 * The famous phrase "with great power Comes Great Responsibility" was shortened from a longer form and attributed to Uncle Ben by Retcon. (It was originally spoken by the narrator.)
 * The Negative Zone, a longstanding element of Fantastic Four stories, was brought into the Ultimate universe under a new name: the N-Zone. Since then, characters have occasionally used this term for the Negative Zone in the regular continuity.
 * Captain America (comics)'s sidekick, The Falcon, briefly wore the same armored costume he wore in the short-lived The Avengers: United They Stand animated series. However, when he rejoined the Avengers a few years later, he ditched the threads.
 * Blade's original powers were being immune to vampire bites, aging slowly and nothing else. He later picked up enhanced senses but didn't really become super in any sense of the word until his film came out.
 * From the classic Age of Apocalypse, we've got the classic Sunfire later sporting his AoA counterpart's look, ironically as a horseman of Apocalypse. Earlier than that, Shadowcat briefly employed a claw device similar to the one used by her AoA self.
 * In the original Black Costume saga, the symbiote did not affect Peter's personality, at all. It just made him tired because it would take his body out crime fighting while he slept. The addition of it making him more violent and mean came from the 90's cartoon.
 * Other:
 * In the original Teenage Mutant Ninja Turtles Mirage comics, Casey Jones was introduced as a fairly loopy vigilante whose motivations mainly seemed to be watching way too much TV. However, in the 2003 cartoon he's given a You Killed My Father backstory involving the Purple Dragons gang and their leader Hun; Hun has since been imported into the Mirage comics, and Casey's background is apparently being updated accordingly.
 * Technically, Hun was loosely based on a scrapped character for the original comics named Copperhead.
 * Since the release of the video game adaptation of The Darkness, the comic adapted a couple traits from the game, notably.
 * As the Scott Pilgrim film (Scott Pilgrim vs. the World) had been in development since the release of Volume 1 (of 6), elements from the script (and interactions with screenwriters Edgar Wright and Michael Bacall) were incorporated by creator Bryan Lee O'Malley into subsequent volumes, per his own confessions. Much of Volume 6 was written during and directly after filming of the movie adaptation, meaning Jason Schwartzmann's portrayal of Gideon had been filmed while O'Malley's conception of the character was in flux, thus influencing the character's depiction in the graphic novel. Furthermore, some shots originating in the film's climax (the elevator with a downward arrow indicating its direction; the overhead angle of Scott on the floor) were directly incorporated into Volume 6. O'Malley has also stated that certain gags (such as the lines "It was just a [bisexual] phase," "You had a sexy phase!?") originated in the film's screenplay and were adapted into the graphic novels with permission, and that certain scenes were inspired by trips O'Malley took around Toronto with Wright and Bacall (such as the Honest Ed's sequence from Volume 3, which apparently came from Wright and Bacall's genuine shock and confusion once they entered the store, and horror upon seeing a particularly grotesque wall-mounted deer-head clock).
 * A minor one from Archie Comics. In the early Sabrina comics, Aunt Hilda & Zelda were an old crone & a chubby green-haired woman, respectively. Around the time of the TV show, they were changed into attractive middle-aged women.

Fan Works

 * Peter Jackson's adaptation of The Lord of the Rings has probably settled for all time the fan arguments over the color of Legolas' hair. He's blond.

Film

 * The live-action G.I. Joe film recast Ripcord (formerly a redheaded white guy) as black. Since then, Ripcord has been introduced in two new continuities - the IDW comicbooks and the G.I. Joe: Renegades cartoon - and in both of them he's a young black man.

Literature

 * J. K. Rowling mentioned in an interview that after she saw the first Harry Potter movie, her own mental image of Snape changed to resemble Alan Rickman, which would then affect the way he's described in the later books.
 * Actually, it seems to have mostly affected how Snape's dialogue is written. Read the "Spinner's End" chapter of Half Blood Prince and try not to imagine Alan Rickman doing Snape's lines.
 * Similarly, both Colin Dexter (Inspector Morse) and Ruth Rendell (Inspector Wexford) have said their mental images of their detectives were dramatically affected by the TV adaptations.
 * Notably, reprints of the novels changed Morse's car from a Lancia to the Jaguar he drove in the TV show.
 * Thomas Harris has been quoted as saying this is exactly why he never watched the movie adaptation of his novel The Silence of the Lambs; not because he disapproved of it, but because he didn't want Anthony Hopkins' portrayal of Hannibal Lecter shading the character's portrayal in the sequels.
 * This is also Terry Pratchett's official reason for not reading Discworld Fan Fiction, along with the legal ramifications that can come with an unintentional (or coincidental) Ret Canon.
 * In the same vein, John Le Carré stopped writing the novels built around George Smiley and the Circus in the early 1980s since, after several wildly popular TV adaptations, he kept seeing Alec Guinness when he wrote the character.
 * In the early Sharpe novels, Sharpe is a Londoner. Following the TV series, later books reveal he fled to Yorkshire as a teenager, where he presumably picked up Sean Bean's accent.
 * After Dr. No was released and made ridiculous amounts of money for all involved, Ian Fleming gave James Bond Scottish ancestry (rather ironic, considering he considered Sean Connery a bad choice for the role at first).
 * In Craig Thomas' novel Firefox, the titular fighter craft was originally nothing more than a MiG-25 Foxbat augmented with state of the art technology. After Clint Eastwood's 1982 movie adaptation came out with its iconic superfighter design, subsequent republishing of the novel would use the movie version of the Firefox to depict the craft. In addition, Thomas changed the description of the plane in the sequel novel Firefox Down to match the new appearance.
 * The Firefox (both the plane and movie plot) is actually an Expy of the 'Mi G-242' from an episode of Gerry Anderson's puppet series 'Joe 90'.
 * The original novel of House of Cards (British series) ends with . This was changed in the TV adaptation, enabling sequels. The two sequels to the novel (both adapted for TV later) are based on the TV ending.
 * Arthur C. Clarke's  2001: A Space Odyssey  originally had the mission going to Saturn. It was changed in the films as they couldn't get the rings right, and that change crept into all subsequent adaptations.
 * At the end of the novel Jurassic Park, Ian Malcolm dies. He survives in the movie, and in the sequel to the book he is the protagonist. On the flip side, several characters who survived in the book but were killed in the movie adaptation are mentioned in the Lost World book sequel as having died from assorted natural causes some time after escaping the island. The only major exception to this is Hammond, who stayed dead in the books and alive in the movies.
 * Other than the basic premise of "cartoon characters are real and live side-by-side with humans" and four important characters (Eddie Valiant, Roger and Jessica Rabbit, and Baby Herman), there are almost no similarities between the book Who Censored Roger Rabbit? (Literature)? and the movie Who Framed Roger Rabbit?. However, the author liked the movie much more than he'd liked his own novel, and when he wrote a sequel, Who Plugged Roger Rabbit?, he followed up the movie's continuity, not the book's (which was even handwaved away as being All Just a Dream).
 * Martin Caidin's Marooned featured a Project Mercury mission. Later editions matched up with the movie and featured a Apollo-style spacecraft.
 * The later novels of Inspector Morse see Lewis become more and more like his TV counterpart. Colin Dexter stated that he found this was also happenning inside his head.

Live-Action TV

 * Mighty Morphin Power Rangers originally had Zordon existing in an limbo dimension, with the tube he spoke out of being only his form of communication. Mighty Morphin Power Rangers The Movie had Zordon being physically in the tube in a pocket dimension and capable of being killed by rupturing that tube. In Power Rangers Turbo (about two years after the first movie) Zordon was magically brought to the physical tube in a pocket dimension, allowing him to return to his homeworld and exist in a state similar to the movie, and in fact became a major plot element of Power Rangers in Space where Zordon is captured.
 * Speaking of homeworld, Power Rangers: The Movie had Lord Zedd Acknowledge that Zordon's home planet is Eltar, something that was never mentioned in the show. Since then, Eltar was mentioned in a few post-MMPR seasons.
 * As of Series IV of Red Dwarf, Lister's backstory with Kochanski was retconned to one closer to what appeared in the novel Red Dwarf: Infinity Welcomes Careful Drivers than had been detailed in the first two series. Originally he'd been hopelessly in love with her, but never had the nerve to ask her out ("In your entire life, your conversations with her totalled 123 words. You had a better relationship with your rubber plant"); in the books they dated for a while, then she got back with "Tim, or Tom, or it may have been Tony" from Catering. The breakup first gets mentioned on screen in the Season IV episode "DNA", and Tim is referenced in Season VII's "Ouroboros" and Season VIII's "Krytie TV".
 * One episode of that series was adapted from a section of a novel, rather than the other way around: the episode "White Hole" is based on the "Garbage World" section of the novel "Better Than Life".

Music
"It feels like I've just lost a girlfriend, because that song isn't mine anymore."
 * After UB40 hit the top of the charts with a reworked reggae version of Neil Diamond's "Red Red Wine", Diamond began performing their version of the song in concert.
 * UB 40's version was based on Tony Tribe's 1971 reggae reworking of the song, but evidently that hadn't been popular enough to justify Diamond changing his arrangement.
 * Johnny Cash's version of Nine Inch Nails' Hurt. Trent Reznor himself even said:


 * Bob Dylan in concert tends to perform Jimi Hendrix's cover of his song "All Along the Watchtower".
 * Billy Joel likes Garth Brooks' version of Shameless so much that he lets Garth come out and sing it when he gives a concert.
 * Noel Gallagher of Oasis went through a phase of doing Ryan Adams' cover of "Wonderwall", most notably on his solo and acoustic tours.
 * Suicidal Tendencies brought in significant funk influences from their side project, Infectious Grooves.
 * Robert Smith, singer and guitarist for The Cure, enjoyed Dinosaur Jr.'s cover of "Just Like Heaven" so much that it has drastically influenced the way that The Cure play the song in concerts.

Radio

 * In its original radio series incarnation, The Green Hornet posited no remarkable skills of The Hornet's valet, Kato. In particular, he was not characterized as either a skilled fighter in general or a martial arts master in particular. However, after the producers of the 1966 television adaptation cast Chinese martial arts master Bruce Lee as Kato, they used every chance they could to show off Lee's martial arts mastery in the series. The television characterization of Kato has been so influential that it is now probably mandatory that Kato be a skilled martial artist in any subsequent adaptation of the property. In the 1990s NOW Comics series of Green Hornet comics, all the Katos were skilled in martial arts, and rumors of various movie adaptations since the 1966 series have always mentioned some prominent martial arts star as having the inside track to being cast as Kato.

Tabletop Games

 * Warhammer 40000 didn't even have two-handed Thunder Hammers before Dawn of War gave one to its Force Commander.

Theatre

 * Revivals of a musical with a successful movie version will often try to find places to add songs written for the movie back into the show. E.g. Cabaret, The Sound of Music.
 * Revivals of Anything Goes invariably include "It's De-Lovely," "Friendship" and other Cole Porter songs originally written for other shows.
 * The licensed version of The Wizard of Oz as a stage musical still has those damn ruby slippers, while the originals were silver.

Theme Parks

 * After the Pirates of the Caribbean movies became popular, references to the characters were added to the original Disney World ride, along with several animatronic appearances of Captain Jack Sparrow. The latter are particularly jarring, as all of the original characters are cartoony caricatures of human beings, but Jack is a perfect likeness of Johnny Depp's character (although Depp himself may be sufficiently cartoony to justify this).
 * More jarring is the sound. Jack Sparrow and redone sound clips mentioning him sound very clear, while any audio still from the original version of the attraction is far scratchier.

Video Games

 * Mortal Kombat's Kano was originally American raised in Japan, but after the first (surprisingly good) film, Trevor Goddard's Australian interpretation was sufficiently well received for him to become an Aussie in the games. Just to complete the mess, Goddard was actually a Londoner who spent his entire life acting as an Australian in order to fill a gap in the Hollywood market. Other elements of the movie which made the cut for the games are the importance of winning ten tournaments, Kitana as Liu Kang's Love Interests, and Johnny Cage and Goro's rivalry.
 * As of MK9, the Ship Tease between Johnny and Sonya (assumed to be canon on most fans' part anyway) became canon, albeit in the form of Belligerent Sexual Tension (at first, anyway; Sonya mellows out a bit towards Johnny over time).
 * Also, Raiden in later games seems to be heavily influenced by Christopher Lambert's portrayal in the movies, specifically his long white hair, his dry sense of humor, and the fact that he is forbidden from directly interfering in the tournament.
 * The Kirby platformer Kirby Squeak Squad, redesigned Dedede's palace to resemble the one from the anime adaptation. The room where Kirby fought Dedede even contained the monster summoning device from the series.
 * Similarly, the GBA remake of Kirby's Adventure features the Fountain of Dreams from Super Smash Bros. Melee, complete with its remixed stage music.
 * Before the anime, Plasma Kirby had pink skin. Since the anime depicted him with green skin, subsequent games followed suit.
 * Super Star Ultra and Mass Attack started giving attention to Sword and Blade as Meta Knight's followers, most likely because they were in the anime (where Axe, Mace, Trident, and Javelin were nowhere to be seen).
 * Kirby's Catch Phrase "poyo!" and Dedede's Verbal Tic "zoi" are both originally from the anime, as is Meta Knight's habit of wrapping his cape around himself.
 * Escargo(o)n, Customer Service, and Macho-San/Max Flexer appear in different extra minigames in Kirby Mass Attack.
 * On the subject of Smash Bros., that game influenced how Captain Falcon was portrayed; all of his appearances after the SSB games now have him with all of his Smash Bros. moves intact.
 * To a degree. It overlaps with Ascended Meme as well. In F-Zero GX, the song that played during the credits reel when you completed Story Mode mentioned the Falcon Punch, hinting that it was one of his canon abilities. In Falcon Densetsu/GP Legend, Falcon gets to finally show his moves during the Grand Finale; it was indisputably AWESOME.
 * Pokémon. Red and Blue versions didn't take the TV show into account. Later versions do. It shows.
 * Pokemon Yellow is basically Red and 'Blue altered to match the anime. Pikachu is the starter, Jessie and James appear regularly, the Pokemon designs reflect their TV appearances (rather than the Off-Model, Nightmare Fuel-inducing original sprites,) and the main Team Rocket mons are uncatchable (because Ash would never catch 'em.) Surprisingly, one of the uncatchable mons is Weedle, which Ash attempted to catch in the anime.
 * Brock mentions his wanting to be a breeder in the games as well. The nurse sprite was altered to match Nurse Joy.
 * Misty obtains Togepi in anime. Misty has a Togetic in games. Togepi evolves in anime.
 * Sonic's love of chili dogs featured in DiC's animated adaptations didn't come from any of the games, but it eventually made its way into Sonic Unleashed, which features numerous food items Sonic can obtain, including chili dogs, described as his favorite.
 * And Sonic Chronicles.
 * Made awesome in the intro to Sonic and The Black Knight.
 * Also, Shadow taking off his rings for an energy boost came from Sonic X, but has since appeared in Sonic 2006.
 * In addition to that, Sonic Chronicles features the SWATbots from the old Sonic cartoon as enemies.
 * Dr. Eggman used to only be called Robotnik outside of Japan, and vice versa. Now his full name worldwide is Dr. Ivo "Eggman" Robotnik.
 * In the games, Ivo "Eggman" Robotnik, while having his robotic minions, he didn't have any close sidekicks like in some animated series, in Sonic Colors he have Orbot from Sonic Unleashed (early named SA-55 but since it was never spoken, it was easily changed) and the new character Cubot, who as a duo they fill that role.
 * The idea of pairing Luigi and Daisy might be the only plot element from the Super Mario Bros movie that was actually adapted into the video games (Though "Mario Mario" and "Luigi Mario" has popped up in NoA made media). In her debut in Super Mario Land, Daisy was simply a Peach Expy for that game and it wasn't until the later Mario Party and Sports games that the idea of having her as Luigi's love interest came about.
 * Many elements from the various media adaptations of the Street Fighter franchise ended up being used in the backstories of later games. Most notably, Street Fighter II: The Animated Movie greatly influenced the plot of the Street Fighter Alpha prequel series, from M. Bison's more muscular design to the origin story of Ryu's red bandanna. Masahiko Nakahira's manga adaptation of the first Alpha game featured a storyline involving Ryu being possessed by the Satsui no Hadou, the same power used by Akuma; this concept would be reused for Ryu's storyline in' Alpha 2.
 * The real reason of this may not be Ret Canon (simply convenience for the artists of the scene), but Guile's intro in Street Fighter IV shows him holding Charlie's dog tags, on which the name "Charlie Nash" is written ('Charlie' is his name in western territories, while 'Nash' is his name in Japan). While the true use of this probably is to avert having to redraw the scene for Japanese audiences, the name 'Charlie Nash' is a common Fanon name as well as the name given to Charlie in UDON's comic book series (which is how it fits into this trope).
 * The Worlds of Power series of children's books based on NES games ended up affecting two games' sequels.
 * "Kal Torlin", which was the name of the land where Shadowgate took place, was first used in Before Shadowgate and ended up used in Shadowgate 64.
 * Eve, the young woman Jason falls in love with in the novelization of Blaster Master, ends up being his wife in the sequel Blaster Master: Blasting Again for the PlayStation. The author of the book was surprised to find out that his character had become canon.
 * Square Enix cannot decide as to whether Cloud stabbed Sephiroth and chucked him into a mako reactor in a Heroic BSOD Roaring Rampage of Revenge, or if Sephiroth just jumped in himself to spite Cloud and because he had foreknowledge of the power of The Lifestream. This plot event is slightly different in the three games and one cartoon it's featured in.
 * Updated Release Fire Emblem: New Mystery of the Emblem several details that were simply Word of God, such as Ogma being a former gladiator, and made them part of the characters official backstories through its support conversations. There's also a Downloadable Content map which centers around a dual between Ogma and Nabarl/Navarre similar to the second episode of the short-lived anime.

Western Animation

 * Transformers Animated has a group called the Cybertron Elite Guard serving as the commanding military and security force for the Autobots. Then, the BotCon 2009 theme was about a similar group (with the same winged Autobot insignias) set in G1 continuity called the Cybertronian Elite Guard.
 * In another Transformers example, the Beast Wars toyline originally portrayed the events as taking place on present day Earth and Optimus Primal and Megatron being merely new forms of Optimus Prime and the original Megatron. When the animated series premiered with the events taking place on prehistoric Earth via time travel and Primal and Beast Megatron being made legacy characters, the toyline was changed to match up with the cartoon.
 * Transformers Prime shows heavy influence from the Transformers Film Series including the general appearance of Optimus Prime, Bumblebee and Megatron, as well as Bumblebee's muteness (although he now speaks in generic beeps and tones instead of talking using clips from his radio). Many fans have described the aesthetics of the robots as a mix of Movie-style and Animated-style.
 * The War for Cybertron game was originally loosely set in the same universe as Prime as a prequel, with lots of nods to G1 thrown in as well. However, the sequel is upping the similarities to Prime with Cliffjumper's head design changing from a G1-inspired design to a clearly Prime-inspired on as well as
 * Beast Wars introduced the concept of a robot soul called a Spark, all subsequent material have included this as a major component of the Transformer culture. This was even retroactively applied to all G1 characters, with the original Optimus Prime and Megatron having particularly powerful sparks able to upgrade the forms of Optimus Primal and Beast Wars Megatron.
 * They also introduced Protoforms, though what they are can vary from the equivalent young, infant, or even prenatal Cybertronians, to simply a Cybertronians' basic form. Not every series included them, but a lot did.
 * Generally, when T.V. shows have an episode of Off to See the Wizard, the main female protagonist will have ruby slippers...