Malice: 23rd Century Ultraconversion for Quake is a commercial mod of Quake. While requiring a full, registered version of Quake, it acts like a stand-alone game, employing its own characters, weapons, environments, rules, etc. The player assumes the role of a mercenary named Damage, who works for the boss of an underground crime syndicate, Colonel Bossman. Damage's main mission is to assassinate the head of Takahiro Industries, Bossman's main rival. To do that, he has to venture into his heavily protected headquarters, dealing with security guards and robots on his way.