Unofficial sequel

A sequel is a narrative, documental, or other work of literature, film, theatre, television, music, or video game that continues the story of, or expands upon, some earlier work. In the common context of a narrative work of fiction, a sequel portrays events set in the same fictional universe as an earlier work, usually chronologically following the events of that work.

In many cases, the sequel continues elements of the original story, often with the same characters and settings. A sequel can lead to a series, in which key elements appear repeatedly. Although the difference between more than one sequel and a series is somewhat arbitrary, it is clear that some media franchises have enough sequels to become a series, whether originally planned as such or not.

Sequels are attractive to creators and to publishers because there is less risk involved in returning to a story with known popularity rather than developing new and untested characters and settings. Audiences are sometimes eager for more stories about popular characters or settings, making the production of sequels financially appealing.

In movies, sequels are common. There are many name formats for sequels. Sometimes, they either have unrelated titles or have a letter added on the end. More commonly, they have numbers at the end or have an added word on the end. It is also common for a sequel to have a variation of the original title or have a subtitle. In the 1930s, many musical sequels had the year included in the title. Sometimes sequels are released with different titles in different countries, because of the perceived brand recognition. There are several ways that subsequent works can be related to the chronology of the original. Various neologisms have been coined to describe them.

The most common approach is for the events of the second work to directly follow the events of the first, either picking up dangling plot threads or introducing a new conflict to drive the events of a second story. A sequel to the first sequel might be referred to as a third installment or threequel or second sequel.

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Wikipedia