Why do so many casual games tell you to stop playing them? If you’ve ever run out of lives in Candy Crush Saga or played a Zynga game, you’ve encountered an energy mechanic – you run out of a resource, and have to stop playing while it regenerates or pay money to continue. In this short collection of essays, Zoya Street explores energy mechanics. Each essay weaves in a new idea, and then applies those ideas to key examples from social and mobile gaming, bringing together game design theory with queer theory, anthropology and a study of the recent history of social game design.