As the name implies, the alien weapon is a Pfhor rifle which can be picked up from dead Enforcers and is the only Pfhor weapon the player can use. Enforcers that are burned or blown up do not drop their weapons. The alien weapon has no ammunition, and when emptied it is simply discarded. When in use, the player's HUD does not display a graphic of the weapon or ammunition remaining, instead simply showing static and a "system error 0xfded" message:
The alien weapon has had two very different incarnations:In Marathon, the alien weapon was much like the assault rifle: inaccurate, with a high rate of fire (but no grenades). It also had more of a "backpack" style to it, referencing the early-era Enforcer graphics.
In Marathon 2 and Marathon Infinity, it functions more like a long range flamethrower with slower shots, much like the fusion pistol. This version also has three firing modes: the primary trigger fires a stream of shots directly forward, the secondary trigger alternates firing at right and left 45-degree angles, and pressing both triggers does all three directions at once (but using up the weapon much more quickly).