Retroactive continuity – commonly contracted to the portmanteau word retcon – refers to adding new information to "historical" material, or deliberately changing previously established facts in a work of serial fiction. The change itself is referred to as a retcon, and the act of writing and publishing a retcon is called "retconning".
Retcons are common in comic books, especially those of large publishing houses such as Marvel Comics and DC Comics, due to the lengthy history of many series and the number of independent authors contributing to their development. Retconning also occurs in TV shows, movies sequels, video games, radio series, series of novels, and can be done in any other type of episodic fiction. It is also used in roleplaying, when the game master feels it is needed to maintain consistency in the story or to fix significant mistakes that were missed during play.
The term "retroactive continuity" was popularized by comic book writer Roy Thomas in his 1980s series All-Star Squadron, which featured the DC Comics superheroes of the 1940s. The earliest known use of the term is from Thomas's letter column in All-Star Squadron #20 (April 1983), where Thomas wrote that he heard it at a convention. The term was shortened to "retcon" by Damian Cugley in 1988 on USENET to describe a development in the comic book Swamp Thing, in which Alan Moore reinterpreted the events of the title character's origin. (See "Examples", below.)
Although there is considerable ambiguity and overlap between different kinds of retcons, there are some distinctions that can be made between them, depending on whether they add to, alter, or remove material from past continuity.
Some retcons do not directly contradict previously established facts, but "fill in" missing background details necessary for current plot points. This was the sense in which Thomas used "retroactive continuity", as a purely additive process that did not "undo" any previous work. Kurt Busiek took a similar approach with Untold Tales of Spider-Man, a series which told stories that fit between issues of the original Amazing Spider-Man series – sometimes explaining discontinuities between those earlier stories.
Related to this is the concept of shadow history or secret history, in which the events of a story occur within the bounds of already-established (especially real-world historical) events, but have been hitherto unrevealed.
Alan Moore's additional information about the Swamp Thing's origins didn't contradict or change any of the events depicted in the character's previous appearances, but changed the underlying interpretation of them. This verges on making alterations to past continuity.
Retcons often add information that effectively states "what you saw isn't what really happened" and then introduces a different version. This is usually interpreted by the audience as an overt change rather than a mere addition. The most common form this takes is when a character shown to have died (sometimes explicitly) is later revealed to have survived somehow. This is well known in horror films, which may end with the death of the monster, but when the film becomes successful, the studio plans a sequel, revealing that the monster survived after all. This has been done many times in superhero comics, so frequently that the term comic book death has been coined for it. The first famous example in popular culture is the return of Sherlock Holmes.
Sometimes retcons are used to keep characters from aging or to keep them contemporary to the audience. A character who served in the army during World War 2 might have his service record retconned to place him in the Korean War, the Vietnam War, the Gulf War, etc. This is similar to a problem faced by many works of future history: the events they describe happening in years after the initial publication do not conform to history as it actually happens. To accommodate such discrepancies, retcons may be used in later stories that alter dates or other details. (See Star Trek examples, below.)
While retconning is usually done without comment by the creators, DC Comics has on rare occasions promoted special events dedicated to revising the history of the DC Comics universe. The most important and well known such event was the mini-series Crisis on Infinite Earths; this allowed for wholesale revisions of their entire multiverse of characters. It has been argued that these were not true retcons, however, because the cause of the changes to their universe actually appeared within the story, similar to stories in which a time-traveler to the past changes history from how he remembered it.
Sometimes retconned alterations are so drastic as to render prior stories untenable. Many of the retcons introduced in Crisis on Infinite Earths and DC's later Zero Hour were specifically intended to wipe the slate clean, and permit an entirely new history to be written for the characters. This is commonly referred to as a reboot.
Unpopular stories are sometimes later ignored by publishers, never referred to again, and effectively erased from a series' continuity. They may publish stories that contradict or explicitly establish that the previous story "never happened". An unpopular retcon may even be re-retconned away. Whether the publisher supports it or not, fans may use Krypto-revisionism to ignore a particular retcon, itself a form of meta-retcon stating that "it was never published". Similarly, fans may invent unofficial explanations for inconsistencies, the challenge itself becoming a source of entertainment. (See Fanon (fiction), Soap Opera Rapid Aging Syndrome.)
An example of subtraction can be found in Ian Fleming's series of James Bond novels. Fleming was unhappy with his novel The Spy Who Loved Me, and subsequent stories ignored and even directly contradicted the events of the book.
Retroactive continuity is similar to, but not exactly the same as, plot inconsistencies introduced accidentally or through lack of concern for continuity; retconning is usually done deliberately. However, retcons are sometimes created after the fact to explain such mistakes. It is also generally distinct from replacing the actor who plays a part in an ongoing series, which is more properly an example of weak or loose continuity (i.e. the different appearance of the character is ignored), rather than retroactively changing past continuity.
Retconning is also distinct from direct revision; when George Lucas re-edited the original Star Wars trilogy, he made changes directly to the source material, rather than introduce new source material that contradicted the contents of previous material. However, the later series of Star Wars prequels did qualify as "new source material", and many fans have pointed out instances that apparently retcon elements of the original trilogy. (See below.)
The "clean slate" reinterpretation of characters - as in movie and television adaptations, or the reintroduction of many superheroes in the Silver Age of Comics - is similar to a reboot retcon, except that the previous versions are not explicitly or implicitly eliminated in the process. They are merely alternate or parallel reinterpretations.
The following examples are not comprehensive. For the sake of brevity, neutrality, and factuality, they don't attempt to explain or justify alteration-type retcons in the context of their respective continuities (a popular activity among some fans), nor do they address the real-world reasons for them.
- When Alan Moore took over writing Swamp Thing, he wrote a story revealing that the title character was not Alec Holland transformed into a monster, but - to the surprise of both the readers and the character - was instead a monster that had grown from plant material infected with the memories and personality of the deceased Alec Holland.
- The deceased Phoenix was revealed to be not Jean Grey but an alien force masquerading as her, thus allowing other superheroes to discover Grey's body and resuscitate her. Other popular comic book characters whose deaths were retconned away include Green Goblin, Nick Fury, The Punisher, Green Arrow, Colossus and Spider-Man's Aunt May.
- Prior to Crisis on Infinite Earths, DC Comics featured characters who lived on a variety of alternate versions of Earth; afterward, these characters were said to have always lived together on the same Earth. Many characters' origins or back-stories were altered, and Superman, Wonder Woman, Hawkman, and other characters were fully rebooted. A second major set of retcons in DC Comics was in a similar event called Zero Hour, which rebooted the Legion of Super-Heroes.
- Before the 1980s, Spider-Man writers stated that Peter Parker's love interest Mary Jane Watson did not know he was Spider-Man. It was later retconned that she had known of Peter's dual life since it began.
- J. Michael Straczynski's run on Amazing Spider-Man has included several retcons, ranging from the mild (raising the possibility of a mystical/totemic origin for Spider-Man's powers) to the drastic (revealing that Gwen Stacy had given birth to Norman Osborn's children).
- The symbiote Venom was originally said to have merged with Eddie Brock because he was suicidally despondent and resentful of Spider-Man. However, it was later presented that Eddie had been diagnosed with terminal cancer, and the symbiote had chosen him as a host because the cancer caused him to produce more of the adrenaline that it "feeds" on.
- The Batman origin story Batman: Year One stated that Police Commissioner James Gordon was childless, contradicting stories set in the present involving his daughter Barbara (Batgirl). It was then retconned that Gordon was the uncle and adoptive father of Barbara.
- In the Yu-Gi-Oh! manga, it is explained by Sugoroku Mutou (a.k.a. Solomon Moto or "Grandpa") in the first chapter that a team of British archaeologists took the Millennium Puzzle out of a pharaoh's crypt in the Valley of the Kings, and that they all died afterwards. In a later chapter, it is revealed that Sugoroku Mutou discovered the puzzle in 1960 in a tomb that had not been successfully breached by anyone else, including a team of British archaeologists.
- The 2004 series Identity Crisis included a retcon involving the rape of Sue Dibny (wife of the Elongated Man) and the brainwashing of several other characters, notably Batman.
- In the final issue of XO Manowar, it was revealed that the entire series up to that point (and perhaps the entire Valiant Universe as a whole) was a dream — or, more precisely, a prophetic vision of a possible future. The final panel of XO Manowar #68 features a slightly modified version of the first panel of XO Manowar #1.
- The 88MPH Studios series Ghostbusters takes place in the same continuity as the first film, but retconned out the sequel, Ghostbusters II. Rather than facing massive debt and going out of business like in the second movie, the Ghostbusters became a global organization.
- The first issue of Marvel's original Transformers comic begins by explaining the history of sentient mechanical life on Cybertron as a natural evolution process. This was later retconned in issues #60-#61 with the introduction of Primus, a god-like being dating back to the creation of the universe itself, who created the Transformers as a "last line of defense" against Unicron.
- In the 1940s radio serial The Green Hornet, the crime-fighting hero's faithful manservant Kato was originally described as Japanese. In 1941, in anticipation of hostilities between the United States and Japan, his ethnicity was changed to Filipino.
- In the sitcom Cheers, Frasier Crane said that his father was a deceased research scientist. However, the spin-off Frasier featured Frasier's father Martin as an ex-cop living in Seattle. Frasier later explained that he had lied to his friends in Boston after having a bitter argument with his father. The existence of his brother Niles was never referred to in Cheers, but was added for the spin-off.
- An entire season of the soap opera Dallas was later dismissed as Pam Ewing's dream, including the death of her ex-husband Bobby, who famously emerges from a shower as if it nothing had happened. The spin-off series, Knots Landing continued as though the events of this season had occurred, and the two series never crossed paths again (this is parodied in the animated series Family Guy).
- The final episode of Newhart revealed that the entire series had been a dream of Bob Newhart's character from the earlier series The Bob Newhart Show, by showing him wake up in bed with his former co-star Suzanne Pleshette, briefly reprising her role as his fictional wife Emily. Unlike most other examples, this was done for comedic effect.
- A similar plot device was used in the final season of Roseanne, stating that Roseanne's husband had died of a heart attack at the end of the previous season, and the final season was all her self-delusion.
- In the popular children's TV show Captain Planet and the Planeteers, the character Linka was originally referred to being "from the Soviet Union" in the opening credits. When the Soviet Union collapsed on December 25, 1991 she became "from Eastern Europe" instead.
- The introduction of other Gundam model mobile suits between Mobile Suit Gundam and Zeta Gundam in the Universal Century Gundam, particularly those models that are more technically advanced than the Gundam MK2 prototype from Zeta, as well as stylistic changes to other mobile suits in Gundam 0080, Gundam 0083 and Gundam - The 08th MS Team. Similarly, the movie Gundam Wing: Endless Waltz replaces the heroes' final Gundams from the television series with much more elaborate redesigns courtesy of Hajime Katoki.
- In the sci-fi series Lexx, the key to the Lexx spacecraft is stored in the hand of the captain (episode 1.02, "Supernova") and is released as the captain dies (episode 1.01, "I Worship His Shadow"). In later seasons, the key is stored in the captain's brain (episode 3.08, "The Key") and can be released even when the captain's life is merely threatened (episode 4.01, "Little Blue Planet").
- In the 1970s TV series Wonder Woman, the character's backstory was altered during the second season. During the first year, it was established that Wonder Woman had never left Paradise Island nor encountered men prior to travelling to the US to help fight World War II. In the second season, the character dropped numerous hints that not only did she encounter various men previously (e.g. a Chinese acupressure specialist she had met "centuries ago", and references to historical figures she had met) but that she may have been active as either Wonder Woman or in some other crime-fighting guise as early as the 19th century.
- In the soap opera One Life to Live, Dorian Lord originally tried to pass off her adopted grandson's girlfriend Adriana as her long-lost daughter. Later it was stated that Adriana is in fact her daughter.
- In the soap opera Passions, Sheridan Crane originally believed she had killed her lover Luis' father Martin when she was a child. In 2004, it was revealed that Martin (and Sheridan's supposedly dead mother) were alive. Then it was revealed that Sheridan had stabbed Martin in the back. In 2005, the story was changed to say that Sheridan killed her aunt Rachel.
- In the TV series Buffy the Vampire Slayer the character of Angel was not originally penned as a vampire with a soul, though this retconning later in the series did not actively contradict previous episodes.
- In the sitcom Full House, Uncle Jesse goes back to high school to get his degree after admitting to dropping out. This contradicts an earlier episode where he attends his five-year high school reunion. In that episode, he remarks as he rides his motorcycle into the gym in a flashback sequence, "I'm graduating tomorrow, what are they gonna do, expel me?"
- Retcons abound in the British TV series Red Dwarf - such matters as what century the characters originated from, how many people were on the ship and many others have been changed. Series co-creator Doug Naylor has gone on record saying that they have always had a very relaxed attitude to continuity, and if something could be changed for the better then they would change it.
- The Odd Couple had three episodes presenting different versions of how Oscar Madison and Felix Unger first met: in the Army, on jury duty, or as children.
- Near the end of the Frieza Saga in Dragon Ball Z, it is revealed that Goku is the Super Saiyan, fulfulling a legend that there would be one born every thousand years. However, as the story continues, every other Saiyan character in the story eventually attains the state of Super Saiyan.
- In South Park, Kenny dies in every episode, yet is always alive to die in the next, as a running gag.
- The Simpsons is known for having very casual continuity, with events in any given episode routinely ignored or blatantly contradicted in later episodes.
- Notable examples of movies in which the monster or villain is revived in sequels include James Whale's Frankenstein, the original 1954 Godzilla movie, the Friday the 13th series, and the revival of the seemingly-vaporized Chief Inspector Dreyfus in Revenge of the Pink Panther.
- Although there is evidence that George Lucas planned them all along, some consider the revelations in The Empire Strikes Back about the fate of Luke Skywalker's father, and in Return of the Jedi about his relationship to Princess Leia, to be retcons. In the first case it contradicted Obi Wan Kenobi's statement in A New Hope that Darth Vader betrayed and killed his father, and in the second case it altered the previous character dynamics between Luke and Leia, particularly some romantic implications.
- By their very nature, the Star Wars prequels are loaded with retcons in the broader sense of the term, such as a previously unmentioned relationship between Yoda and Chewbacca introduced in Revenge of the Sith. The prequels also contain some overt revisions of history, such as The Phantom Menace revealing that C-3PO and R2-D2 knew the Skywalkers, despite their apparent unfamiliarity with Luke's family and Tatooine itself at the beginning of A New Hope (partially explained by C-3PO's memory wipe at the end of Revenge of the Sith, coupled with the ambiguity of R2-D2's unintelligible dialogue, though this does not explain why the Skywalkers do not recognize their former droid).
- In the second Highlander film it is revealed that the Immortals are aliens from the Planet Zeist, although no mention of this is made in the first film, and exposition as to the nature of "The Game" is inconsistent with the implications of the first film. These developments are largely ignored in the subsequent films, as well as the television series, which also retcon Connor's triumph in the original Highlander as merely a major victory, rather than the final battle of "The Game."
- The film Superman Returns is a direct sequel to Superman: The Movie and Superman II. It disregards the events of Superman III and Superman IV: The Quest For Peace.
- The film Halloween H20: 20 Years Later is a direct sequel to Halloween and Halloween II, dismissing the events that take place in the sequels Halloween 4, Halloween 5, and Halloween: The Curse of Michael Myers. (Halloween III was an unrelated story unaffected by the retcon.) The subsequent film Halloween: Resurrection follows the new continuity of Halloween H20.
- In the film Terminator 3: Rise of the Machines, the fact that history had been changed in favor of humanity was completely negated and the eventual nuclear holocaust that would begin the war between Skynet and humanity happened anyway (but was only slightly delayed).
- The film Clue was originally shown in theatres with one randomly chosen ending from a pool of three; the VHS release and subsequent television airings included all three endings. Each ending had at least one discontinuity that was retconned within the context of the film's story itself.
- In art based on mythology, the opening of a poem or play is often based on an assumption which explicitly changes the source material. A famous example from Greek drama is the premise of Euripides play Helen, which explains its premise early in the work. The play recounts that Helen of Troy did not run off with Paris (thereby inciting the Trojan War), but was whisked away to Egypt by Hera.
- Sherlock Holmes reappears in The Adventure of the Empty House following Watson's report of his death in Arthur Conan Doyle's "last" Holmes story The Adventure of the Final Problem.
- J.R.R. Tolkien rewrote the way Bilbo Baggins acquired his Ring in The Hobbit, to better suit the story he wanted to tell in The Lord of the Rings. Narratively this was explained by depicting the original version as a misrepresentation perpetuated by Bilbo – already under the Ring's influence – and only later corrected.
- In the television series M*A*S*H Colonel Henry Blake was killed immediately following his service in the Korean War. In Richard Hooker's sequels to the novel the series was based on, he retconned this, establishing that Blake had survived the war.
- In his sequels to the novel version of 2001: A Space Odyssey, Arthur C. Clarke made slight alterations to background history in order to keep each novel consistent with progressing developments in the real world. He also changed the location of the third monolith from Iapetus to the Jupiter system, to conform with the movie version of 2001 by Stanley Kubrick. Clarke has stated that each sequel to 2001 exists in its own continuity and follows the film rather than the book.
- In the book Jurassic Park, Ian Malcolm is said to have died at the end. However, in its sequel, The Lost World, Ian Malcolm's death turns out to be a misreporting of the incident, bringing the books into line with the movies, in which he did not die. Additionally, characters who survived in the book but were killed in the film (such as the lawyer Gennaro and the gamekeeper Muldoon), are mentioned in The Lost World novel as having died shortly after the park incident (e.g. from illness or a plane crash).
- So Long and Thanks for All the Fish from the Hitchhiker's Guide to the Galaxy series is set in a parallel universe where the destruction of planet earth never took place, and Arthur Dent returns home, telling his friends he had "a marvellous time in California" and has had a "face-drop" to look substantially older than he should be.
Star Trek in various media
- The Star Trek: The Original Series episode, "Space Seed" referred to the Eugenics Wars as a conflict taking place in the 1990s. Greg Cox's series of Star Trek novels, written after the 1990s, attempted to retcon the wars into shadow affairs hidden by real-life major conflicts, but the producers of the TV series don't consider the novels to be canon. A 1996 episode of Star Trek: Voyager ("Future's End") was set in a year when the wars should have been a current or recent event, yet no mention of them was made. A 1998 episode of Star Trek: Deep Space Nine ("Dr. Bashir I Presume?") contained a statement in the script that suggested the wars took place in the 22nd Century (although this has been acknowledged as an error). A 2004 episode of Star Trek: Enterprise stated that the Eugenics Wars were a wide conflict in which 30 million people died, but without identifying the timeframe; the producer of the series, however, stated that the Eugenics Wars as referenced in the episode still occurred in the 1990s.
- When Star Trek: The Motion Picture was released in 1979, Gene Roddenberry claimed that the radically different appearance of the Klingons in the film was how they were always supposed to have looked, but they didn't have the budget for it in the 1960s. In the 1990s, an episode of Star Trek: Deep Space Nine featured three Klingon characters from the original series, made up to fit the new look. However, the later episode "Trials and Tribble-ations", used footage from the original series with old-look Klingons; Commander Worf acknowledged their different appearance, adding that it was "a long story" that Klingons "do not discuss with outsiders." A two episode arc of Star Trek: Enterprise ("Affliction"/"Divergence") in 2005 indicated that Klingons resembling the 1960s portrayal were the product of genetic engineering using augmented human genes, essentially retconning the retcon.
- The character of Zefram Cochrane was presented in the original Star Trek episode "Metamorphosis" as a dignified scientist from Alpha Centauri who had apparently invented warp drive as part of a mainstream research project. When he appeared in Star Trek: First Contact, the character's place of origin had been retconned to Montana, he was an eccentric alcoholic, and he invented warp drive working alone with equipment salvaged from an abandoned missile launching facility.
- A sequel to Metal Gear titled Snake's Revenge was produced for the North American and European markets without the involvement of Hideo Kojima or any of the original game's development team. When Kojima later designed Metal Gear 2: Solid Snake, the events of Snake's Revenge were disregarded and the game has been removed from the series' canon.
- In Metal Gear 2: Solid Snake it was revealed that Big Boss was Solid Snake's father, but in the sequel, Metal Gear Solid, Snake is actually a clone of Big Boss. Snake also killed Gray Fox in Metal Gear 2, but in Metal Gear Solid, Gray Fox is revealed to have survived, but barely alive after the battle with Snake, and been turned into a cyborg ninja.
- Metal Gear Solid 3: Snake Eater, which took place in 1964, as opposed to the previous games, which took place from 1995 to 2009, follow the exploits of Big Boss and Ocelot, adding many details about their past and motivations, and details about the story in general. A few minor details from the previous games were retconned, such as the loss of Big Boss' right eye (originally established to have been lost during the 1980s) and Ocelot's age during the events of Metal Gear Solid (originally established to be in his fifties).
- The Mortal Kombat character Kano was originally an American born in Japan. Following Trevor Goddard's portrayal of Kano as an Australian in the film adaptation, the character was rectonned to be Australian in Mortal Kombat: Deadly Alliance.
- In Super Metroid, the player explores an area called the Wrecked Ship. The game's manual explains it as belonging to "astronauts from an ancient civilization" who allegedly crash-landed on Zebes. However, in Metroid: Zero Mission, a ship belonging to Space Pirates is located in approximately the same place.
- In the first scene of Grand Theft Auto III, 8-Ball has bandaged hands; the newspaper that tied in with the game stated that the police had accidentally spilled hot grease on his hands when they took him into custody. However in the prequel Grand Theft Auto Advance 8-Ball was badly burned by a flamethrower before he was arrested.
- In Myst, the brothers Sirrus and Achenar were trapped in Trap Books, in the void between the Ages. If the player frees them, he is trapped himself. Originally, Atrus presumably burned the books, thus trapping or killing his sons forever. This was revised to say that the brothers were not trapped in the void, but in desolate Ages.
- After developing Twisted Metal and Twisted Metal 2, SingleTrac left Sony. Twisted Metal 3 and Twisted Metal 4 were developed by Sony's 989 Studios. The original developer later returned and created Twisted Metal: Head-On, a direct sequel to Twisted Metal 2 which disgarded the events of Twisted Metal 3 and Twisted Metal 4.
- Similar to Star Trek: The Motion Picture, the Kilrathi of the Wing Commander movie were different in appearance to those in the Wing Commander games. Chris Roberts claimed that this was how they were always supposed to have looked, but they didn't come up with their definite appearance while making the games.
- In Street Fighter II, Guile seeks revenge against M. Bison for killing his best friend, Charlie in the Vietnam War, over 20 years before. However, this is revised in each game that Charlie has appeared in. The final canon version, as depicted in Guile's ending in Street Fighter Alpha 3, has Charlie dying while working with Guile and Chun-Li to destroy Bison's Psycho Drive.
- The ending of Monkey Island II: LeChuck's Revenge showed Guybrush traveling through a portal and leaving the game's universe and entering into "our" world as a small child. The next part of the saga, The Curse of Monkey Island, opens with an adult Guybrush, back in the game's world, who explains he had been enprisoned by LeChuck in a magical amusement park.
- The villian Evil Mistake in the webcomic Dandy and Company attempts to makes use of a "retcon cannon" to rewrite the universe to his liking.