Paranoia 2: Savior is the standalone sequel to the Half-Life mod Paranoia, which was ported to the Xash3D engine as Paranoia: The Game. Paranoia 2: Savior takes place shortly after the first game, putting the player back in the shoes of Major Alexander Kalashnikov as he continues his descent into the abandoned KROT-1 laboratory. The deeper Alex descends, the more he learns about the experiments that took place there, discovering that the monsters within must be eradicated at any cost. Like the first game, Paranoia 2 is a horror-oriented linear first-person shooter. The player's arsenal consists solely of realistic military weapons, such as pistols, rifles, and machine guns, which can be refilled with ammo found around the environment or scavenged from enemies. First aid kits and painkillers can be used to restore lost health points, but only painkillers are light enough to be carried and saved for later. The player is also outfitted with a retractable helmet which can be used to reduce incoming damage to the head and a gas mask which is vital for traversing areas contaminated with toxic gas.