The Sawed-Off Shotgun is a weapon introduced in Eternal Damnation. It was ported into A Week in Paradise, and is one of the most powerful guns in the game. Before the latest patch of the original AWP (1.3), this weapon would not get confiscated from your player when something would cause you to lose all your weapons. It also shoots a lot of bullets all at once doing massive damage to its target, able to kill strong enemies. A single round for it is actually both shells fired at once very quickly and the dude has to do a reloading animation.
The gun makes a comeback in Postal 2 Complete and returns with its original settings, directly from Eternal Damnation, and with slicing and door-destructive power. The shooting speed is also a bit slower, so that the player can shoot 2 separate shots before reloading, rather than 1 shot and reload. It also now shares its pool of ammo with the Shotgun, the Shotgun...? and the Lever-Action Shotgun.