A sourcebook for playing mercenaries in the Traveller universe. An overview of the nature of war and those who fight wars is provided, with notes on the Imperial laws of war. There is a guide to running mercenary campaigns, with a breakdown of weapons systems by tech-level, from low TL black powder up to high TL battledress and fusion guns. Weapons and vehicles are statted out, and character templates are provided for various military types. Sample missions are provided, and some example units and characters.