The following weapons appear in the video game Alien: Isolation:
The .357 Revolver, manufactured by the fictional Spearhead Armoury, is the only sidearm featured in the game and is frequently used by the many human survivors and security personnel aboard Sevastopol Station, most notably Axel. Right after Amanda Ripley (the player character) enters an office in the Lorenz Systech Spire, she can acquire the .357 Revolver, which can be found on a table in said office. However, while the player cannot pick up any revolvers dropped by dead humans, they can loot the corpses for ammunition (even before the revolver is acquired).
Gameplay-wise, the .357 Revolver is a 6-round, semi-automatic revolver chambered for the fictional .357 LR cartridge and appears to be based on both the Chiappa Rhino 50DS and Mateba Model 6 Unica. Like both revolvers, it fires from the bottom chamber of the cylinder. Depending on the shot placement, the revolver has decent stopping power against human survivors, but may struggle considerably with taking down Seegson "Working Joes" synthetics, especially the heavily armored ones wearing Hazmat suits. As with all weapons in the game, its iron sights cannot be used and the revolver cannot fatally harm the Aliens encountered in the game. Unlike most video game portrayals of revolvers, the player actually uses the ejector rod to push out the bullets rather than simply shaking the revolver's cylinder downward. In addition, the revolver is reloaded one round at the time and the player must press (or hold) the reload button for each round they wish to insert into the cylinder. However, there are several unrealistic aspects of the revolver's reload animation. First of all, the player simply ejects all the rounds from the cylinder (regardless of whether or not all of them were fired) and the unfired rounds somehow magically hop back into the player's ammo pool. Second, the rounds ejected are all spent casings, even if there were unfired rounds still left in the chamber. Finally, the player swings the cylinder shut with the flick of the wrist rather than pushing it closed with the other hand, which can cause the cylinder to be misaligned and/or the revolver to malfunction.
Model 37-12 Shotgun
The Model 37-12 shotgun, manufactured by the fictional Henjin-Garcia, is carried by Marshal Waits' (William Hope) deputy, Ricardo, and several of the human survivors on the Sevastopol Station. The shotgun is first found on the lap of a dead human survivor in an abandoned hallway right after Amanda Ripley escapes from an Alien-infested Gemini Exoplanet Solutions module jettisoned into space. It is a 12 gauge, 4-round pump-action shotgun that can instantly kill a human with one shot (depending on the shot placement), severely damage Working Joes, and briefly stun the Xenomorph long enough for the player to retreat. Like the .357 Revolver, the player has to press (or hold) the reload button for each round they wish to insert in, although the player does not pump the shotgun after reloading from an empty tube. Strangely, while it features dual underbarrel internal tube magazines, Amanda Ripley never preforms an action to switch between them (although it is possible she could be only using one tube). The shotgun is based on the SWATriplex-18, a prototype shotgun designed in the 1970s by John W. Winter that was never mass-produced.
A custom flamethrower like the one from Alien appears in the Crew Expendable and Sole Survivor DLC, which are set on the USCSS Nostromo during the events of Alien. The flamethrower also appears in the main game and possibly due to time limitations and such, the flamethrower and the one in the DLCs share the same animation model. It can be found in the Solomons Habitation Tower after Amanda Ripley speaks with Marlow and Marshal Waits announces his plan to defeat the Alien. Ellen Ripley (voiced by Sigourney Weaver), Captain Dallas (voiced by Tom Skerritt), and Parker (voiced by Yaphet Kotto) all carry the custom flamethrowers in the DLC. Unlike many of the weapons in the game, the flamethrower actually has an effect on the Alien, as a small burst of flames can force it to temporarily retreat into Sevastopol's vents, giving the player enough time to escape and/or move about the area for a limited amount of time without interference from the Alien itself. However, as with all weapons, it cannot fatally harm the Alien. Interestingly, when using the flamethrower on synthetics, they may occasionally say, "Most animals retreat from fire. I am not an animal," referring to a line spoken by Ash in Alien.
Designed by Chief W. Porter, the fictional "Bolt Gun", which appears to be a futuristic and larger version of a captive bolt pistol, can be first found in the Chief Engineer's Office in the Maintenance Deck when Amanda proceeds down to the Central Reactor after talking to APOLLO. The bolt gun appears to be firing anchored bolts (referred to as "Watasumi Expanding Bolts" in-game) and appears to have parts based off the cattle prods used by the Nostromo crew in Alien (especially the barrel and the battery park taped to the front of the weapon). In the game's universe, the bolt gun is likely used by engineers for repair operations and is a single-shot projectile weapon that can instantly kill the Working Joes equipped with Hazmat suits and anything weaker than it. In order to fire the projectile weapon, the player must hold the trigger for a few seconds to charge it and then release the trigger when ready to fire, making the weapon difficult to use in close quarters. In addition, the Bolt Gun is unable to lethally harm the Aliens as with all the weapons in-game and is too slow and cumbersome to use against the small, but nimble Facehuggers. However, the Bolt Gun, similar to the Shotgun, is powerful enough to briefly incapacitate the Alien.
Futuristic Pipe Bomb
In a flashback to the Anesidora crew's journey to LV-426, Marlow (the player character for this section) uses what appears to be a remotely detonated and futuristic pipe bomb to clear a pile of rocks obstructing the path of his crewmates.