Basic Set: Campaigns combines information from Basic Set, Third Edition and Compendium II - plus our new core setting, with infinite possibilities for timeline-hopping adventure! This book and Basic Set: Characters together replace Basic Set, Compendium I, and Compendium II, plus add new rules. This book is intended for Game Masters and advanced players. It covers physical feats, combat, vehicles and technology, animals and monsters, world design, and Game Mastering. "Tool kit" chapters let you create new creatures (and even PC races), artifacts, character abilities, and entire game worlds. It also features a cross-world setting, Infinite Worlds, which you can use to create cross-genre campaigns . . . develop alternate histories . . . play modern characters in a fantasy world . . . whatever you like! (You don't have to play in the core setting - there isn't some game-altering metaplot - but it's there if you want it.) This is Book 2 of the two-volume Basic Set, and contains everything a GM needs to create and run a GURPS Fourth Edition campaign. Only Book 1 is necessary to play. Book 2 is required for the Game Master, and players wanting more detail will find it valuable.