The Gamemaster's Guide has everything a Mutants & Masterminds GM needs, from guidelines on creating challenges and adventures to advice on designing your own setting and series. It includes guidance on how to set up and run your game and to help your players create the best heroes, archetypes that make building villains easy, world building tips, and options for modifying the game to suit your group's play style. This new Revised Edition of the original book is a handsome hardback that adds two adventures, new villain archetypes and minions, and more.