In the sprawling universe of tabletop roleplaying games, Mutants & Masterminds (M&M) stands as a titan of the superhero genre. Unlike level-based behemoths like Dungeons & Dragons , M&M (specifically the current Third Edition) is a system. This means you don’t pick a spell from a list or a class feature from a tree. Instead, you define what you want your power to do , and then you build it using mechanical building blocks called Power Effects .