Mercenaries - 4th Generation Warfare is a strategy RPG expansion for the base game 4th Generation Warfare. The DLC adds the Mercenary Group Leader character class and 12 distinct mercenary organizations available for official or clandestine contracts. A reputation system dictates service costs and combat effectiveness, where groups gain power and equipment through successful operations for various nations. These units utilize military cargo planes for rapid global deployment and establish camouflaged camps as temporary bases. Tactical options include reconnaissance to reveal hidden units, demolition strikes, and looting military bases to seize enemy hardware. Mercenary leaders utilize specific equipment including assault rifles and self-guided rocket launchers. While these forces enable deniable military operations, discovery triggers international diplomatic penalties, and rival nations may outbid existing contracts to turn these groups against their employers.