Retcon

Retroactive continuity, or retcon for short, is a literary device in which new information is added to already established facts in the continuity of a fictional work.

There are various motivations for applying retroactive continuity. The changes may occur to accommodate sequels or derivative works, allowing newer authors or creators to revise the diegetic (in-story) history to include a course of events that would not have been possible in the story's original continuity. Retcons allow for authors to reintroduce popular characters and resolve errors in chronology. Another form of retroactive continuity involves placing well-known characters in a parallel universe. This approach can be used to allow familiar elements of a story to be explored in an entirely new context, without affecting external elements. This approach can also be used to retcon former events in a franchise timeline.

Retcons are common in pulp fiction, and especially in comic books published by long-established publishers such as DC and Marvel. The long history of popular titles and the number of writers who contribute stories can often create situations that demand clarification or revision. Retcons also often appear in manga, soap operas, serial dramas, movie sequels, cartoons, professional wrestling angles, video games, radio series, and other forms of serial fiction.

Science fiction writers are occasionally confronted with new scientific developments that disprove assumptions made in a previous story or book.

The first published use of the phrase "retroactive continuity" is found in theologian E. Frank Tupper's 1973 book The Theology of Wolfhart Pannenberg: "Pannenberg's conception of retroactive continuity ultimately means that history flows fundamentally from the future into the past, that the future is not basically a product of the past."

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