From publisher blurb:
The Mastermind's Manual is the perfect companion to the award-winning Mutants & Masterminds Superhero Roleplaying Game. In its pages you will find endless ways to customize the M&M system to suit your game, along with helpful Gamemaster advice, and insight into how the game is designed and played. The Mastermind's Manual includes a vast array of optional and variant rules, complete guidelines for creating your own feats and super-powers, expanded systems for proficiency, combat, chases, skill use, and nearly every other aspect of the game. With the Mastermind's Manual, you open up infinite possibilities, infinite options, and the power to truly make the world yours. It's your master plan for taking the game to the next level... and what mastermind wouldn't want that?