Games are a unique art form. Game designers don't just create a world; they create who you will be in that world. They tell you what abilities to use and what goals to take on. In other words, games work in the medium of agency. This book explores what games have to teach us about our own rationality and agency. We have the capacity for a peculiar sort of motivational inversion. For some of us, winning is not the point. We take on an interest in winning temporarily, so that we can play the game. Thus, we are capable of taking on temporary and disposable ends. At the center of this book is a view about games as communicative artifacts. Games are a way of recording forms of agency; they are a library of agencies. And exploring that library can help us develop our own agency and autonomy.