A laser pistol was used by the crew of the USCSS Nostromo. Derived from the technology used in laser welders, the laser pistol was equipped with a 4x20 scope.
In June 2122, these pistols were used by the crew of the Nostromo while investigating the derelict ship on LV-426. Once Ash studied the Facehugger, he warned the crew that using guns against the alien would not only be useless, but dangerous to the ship's hull due to the powerful acidic blood of the creature. Instead the crew used custom made cattle prods and a flamethrower.
The laser pistol was a miniaturized, weaponized version of the laser welders used by Dennis Parker and Samuel Brett aboard the USCSS Nostromo. The pistols used by the Nostromo crew were equipped a 4x20 scope mounted on top of the weapon and an unknown device (possibly a laser guide) on the bottom. The pistols used by the crew of the Nostromo also had "NOSTROMO" and "LIGHT SYNC. DIAL" on the side in the right font Futura Demibold. Presumably, if the pistol were used on another ship, "NOSTROMO" would be replaced with the ship's name.
Some MK 50 Compression Suits in 2122 featured a holster for the laser pistol on their right leg.
Behind the Scenes
In the scripts, these are referred to as laser pistols, in the final film they are never fired and only referred to as "weapons". In the original ending of Alien, Ripley was to find herself hanging outside of the shuttle Narcissus by a cable, with the Alien clinging to the end. Before climbing back aboard she was to shoot the Alien in the head with one of the laser pistols, only for it to have almost no effect on the creature. Storyboards were created for the sequence, but it was later simplified to the version seen on film.
Full-size props of the pistol were based on the Rexim-Favor submachine gun, with their barrels shortened, stocks and magazines removed, "NOSTROMO" and "LIGHT SYNC. DIAL" in the font Futura Demibold added to the side of the pistol used by Kane, 4x20 scopes added to the top and a Singe Point Scope (which was also used on blaster props in the Star Wars films) attached to the bottom of the magazine wells.
A second, smaller version of the pistol was also custom-made, based on a Webley Junior Mk.II air pistol by Webley & Scott. These props consist of a commercial Webley metal air gun with various production modifications, additional dressing including a metal tube with threaded plug in the gun barrel, an added arm and a sight-scope accessory on top, etc. The miniaturized versions were used by the children who played Dallas, Kane and Lambert in some long shots where the pistols were seen in the holsters on the suits' legs, and was scaled down to match their smaller suits. Three of the Webley props were constructed.
- The first film makes point out of never using firearms against the creature. Whereas the first sequel Aliens is all about soldiers easily shooting many of the creatures with guns. The potency of the acidic blood seems to have been retconned and lessened and perhaps the "structural perfection" of the creature itself.
- These pistols appear in Alien: Isolation but are also never fired, even though a .357 Revolver and shotgun can be used by the player.
- NECA's Nostromo compression suit figures Dallas, Kane and Lambert all come with the pistols.
- Hot Toys' Kane and Dallas in compression suit figures also come with the pistols.
- Kubrick's compression suit Ripley figure comes with a pistol rather than speargun.
- In a 35th anniversary lithograph by Dave Dorman, the art depicts a man in a compression suit firing the pistol at an alien and effectively piercing its frontal dome. It is unclear if it is a projectile weapon or something else.