The mainstay of Pfhor Enforcers aboard the Sfiera, the Alien Weapon is the last one obtained by the Security Officer in the first Marathon game. Exotic to aliens and humans alike, this weapon is a dangerous enigma.
The Alien Weapon cannot properly interface with the Security Officer's armor, and registers as an error. However, it is a fully automatic weapon that fires explosive rounds. It is unknown how it fires, or how it can be reloaded.
This weapon does not return in Marathon 2: Durandal, instead replaced by the Enforcer Rifle.
The weapon can only be picked up after killing Pfhor Enforcers, and cannot be reloaded. When empty, the weapon will drop from the player's inventory and a new one will need to be found. The weapon is also much more accurate than the M75 Assault Rifle, as it only has spread along the horizontal axis.
It is capable of gunning down hordes of Pfhor in CQC or picking away at them at range, the hitscan nature of the weapon makes it a mainstay of Marathon's late game.
- When in the player's hand, the weapon screen reads: "UNKNOWN WEAPON CLASS" with "system error 0xfded"
- This is the only alien weapon that the player can use in the first Marathon game.
- If an enforcer is burned to death with the Flamethrower, then they will not drop this weapon.
- There is no reference to this weapon in the game's manual.
- During development, Bungie intended for this weapon to serve as the player's shotgun.