Aliens is a 1986 science fiction action film written and directed by James Cameron. It is the sequel to the 1979 science fiction horror film Alien, and the second film in the Alien franchise. Set in the far future, it stars Sigourney Weaver as Ellen Ripley, the sole survivor of an alien attack on her ship. When communications are lost with a human colony on the moon where her crew first saw the alien creatures, Ripley agrees to return to the site with a unit of Colonial Marines to investigate. Michael Biehn, Paul Reiser, Lance Henriksen, and Carrie Henn are featured in supporting roles.

The action film is a film genre that predominantly features chase sequences, fights, shootouts, explosions, and stunt work. The specifics of what constitutes an action film has been in scholarly debate since the 1980s. While some scholars such as David Bordwell suggested they were films that favor spectacle to storytelling, others such as Goeff King stated they allow the scenes of spectacle to be attuned to story telling. Action films are often hybrid with other genres, mixing into various forms ranging to comedies, science fiction films, and horror films.