It is usually included to reward the audience for having the patience to watch through the credits sequence; it may be a scene written for humor or to set up a sequel.
Post-credits scenes may have their origins in encores, an additional performance added to the end of staged shows in response to audience applause.
[1] Opera encores were common practice in the 19th century, when the story was often interrupted so a singer could repeat an aria, but fell out of favor in the 1920s due to rising emphasis on dramatic storytelling rather than vocal performance.
[3] The scene depicts lead character Matt Helm (played by Dean Martin) lying shirtless on what appears to be a rotating sofa along with 10 scantily-clad women.
Enhanced application continued in 1985 with Young Sherlock Holmes (see below); in Masters of the Universe (1987), Skeletor's head emerges from the water at the bottom of the pit, saying "I'll be back!
The scenes were often used as a form of metafiction, with characters showing an awareness that they were at the end of a film, and sometimes telling the audience directly to leave the theatre.
Post-credits scenes also appeared on the long-running television show Mystery Science Theater 3000, introduced in the 1990 episode Rocket Attack U.S.A., continuing until the end of the series.
Most were short clips that served to tie together loose ends—minor characters whose fates were not elaborated on earlier in the film, or plot lines that were not fully wrapped up.
Even when post-credits scenes started to be used by films with little comedy development, the same format of giving closure to incomplete storylines or inconsequential characters remained in use.
Agent Coulson locating a large hammer at the bottom of a crater in a New Mexico desert, thus teasing the release of Thor the following year.
The post-credits sequence of Captain America: The Winter Soldier introduces the characters of Pietro and Wanda Maximoff, who join the franchise in Avengers: Age of Ultron.