Computer gaming is a global phenomenon and there has been rapid growth in "serious" games for learning. An emergent body of evidence demonstrates how serious games can be used in primary and secondary school classrooms. Despite the popularity of serious games and their pedagogical potential, there are few specialised frameworks to guide K-12 teachers in choosing and using serious games. The purpose of this paper is twofold. Firstly, we draw on recent research to provide an overview of the nature and uses of serious games, current knowledge about their learning efficacy, and the features that teachers should consider when choosing a game. Secondly, we provide a new, practical and comprehensive framework especially designed to guide teachers in making evidence-informed decisions about choosing and using serious games in their classrooms. This framework is organised according to the domains of learning, pedagogy, curriculum, assessment, and technical context.