Alien is the 1979 science fiction film that launched the Alien film franchise. Directed by Ridley Scott, the film revolves around a space transport crew who stumble upon an unknown lifeform that poses a grave threat to their lives. The film launched the movie career of Sigourney Weaver and would spawn three direct sequels: Aliens, Alien³, and Alien: Resurrection as well as the Alien vs. Predator series of films. For the film's twentieth anniversary, a "Director's Cut" of Alien was released with added scenes. Ridley Scott would return to this universe in 2012's Prometheus and 2017's Alien: Covenant.
The following weapons were used in the film Alien:
The main weapon used by the crew of the Nostromo is a flamethrower assembled by Parker (Yaphet Kotto). The customized flamethrower is seen used by Ripley (Sigourney Weaver), Parker (Yaphet Kotto), and Dallas (Tom Skerritt). In a deleted scene reinstated in the 2003 "Director's Cut", Ripley uses the flamethrower to incinerate a nest.
Ripley is seen holding a harpoon gun when confronting the Alien in the escape pod. It is likely based on a Mares Snub Nose.
Before investigating the derelict ship, Dallas (Tom Skerritt) tells the crew to break out the weapons, the larger of which was based on the Swiss Rexim-Favor, the other based on a Webley Junior Mk II Air Pistol. According to the novelization of the film, these are laser pistols. The Rexim-Favor-based weapon features a 4x20 scope and an underbarrel Singlepoint scope (which would make the scope unusable). The Rexim-Favors were used by the actors dressed in full-sized spacesuits, while the Webleys were used by children dressed in scaled down spacesuits, who were used in all wide shots to make the derelict set seem bigger. While not seen being fired, they are seen in holsters on the crew's spacesuits and Kane (John Hurt) is briefly seen holding one in the Director's Cut.