This is an expansion for the base game 5150. From the publisher's website: Infestation introduces the “tactical role-playing game” side of 5150. Players can use Infestation to “flesh out” their characters, giving them an almost life-like feel. Infestation blends the traditional RPG with fast and easy to follow combat on a personal level. Combining these two aspects allows players to enjoy the cinematic aspect of role-playing while keeping the excitement of a miniatures wargame. Infestation covers... Fast movement Firing while fast moving The H'DAN CORPORATION flash-bang grenade New grenade throwing procedures Explosions in confined spaces Delayed explosions New ranged combat chart Specific hit locations and damage Cover handled in a different way Variable damage to figures New melee system Man Down check Computers and hacking New equipment Encumbrance Psionics with new QRS "Half Deads" Complete scenario that introduces new movement system New "in encounter" encounter system New variable time clock for encounters Covert Operations Group with new QRS Covert operations Security robot - with new QRS HAFER-2 Security Bot Xeogs are refreshed to use in the scenario if needed - with QRS New way to play solitaire or same side two new aliens with QRS