The Shotgun is a weapon that can be found after Mission 10 in the Alien: Isolation video game.
It can be found lying on a body shortly after Amanda Ripley arrives onboard Sevastopol Station, but there is no solid answer for where it came from or how it got there. The shotgun has a capacity of four rounds and is a very effective close quarters weapon. One blast is enough to kill any human, even armored members of Seegson Security, and though body shots may not be as effective, a shot to the head can kill any Working Joe instantly. Unfortunately, ammunition is scarce and the shotgun requires ample time to reload, meaning players must be cautious of their surroundings and manage their reserves wisely.
DesignThe design of the Model 37-12 Gauge Pump Action is primarily based on the SWATriplex-18, an obscure prototype 12 gauge semi-automatic combat shotgun that was designed in the late 1970s by John W. Winter. The shotgun was never mass-produced because Consortium W, the company which was supposed to manufacture the weapon, pulled out after only a few prototypes were built and Winter was never able to attract anyone else to manufacture his shotgun.
While the 37-12 in Alien: Isolation is mainly based on designs in Alien, many small details take inspiration from Aliens. The "vents" on the front of the barrel are clearly inspired by the M41A Pulse Rifle's barrel vents and the section of the 37-12 with the pump handle is inspired by the Pulse Rifle's grenade launcher attachment, which used the handguard and slide action sleeve of a Franchi SPAS-12 in its construction (for the film props).
Additionally, like the flamethrower in the game, the pistol grip of the 37-12 appears to have been slightly based on the grip of the Rexim-Favor-based laser pistol seen briefly in Alien. In fact, the laser pistol was apparently originally going to be usable in the game, being featured in numerous pieces of concept art, but it only appears in a drawing of Marshal Waits in the final version.
The low 4-round capacity of the 37-12 seems strange, especially considering that it features dual underbarrel tube magazines. However, Ripley is never seen performing an action to switch between the tubes during reload animations, so it is possible she only ever loads one of them.