More than 174 million Americans are gamers, and the average young person in the United States will spend ten thousand hours gaming by the age of twenty-one. According to world-renowned game designer Jane McGonigal, the reason for this mass exodus to virtual worlds is that video games are increasingly fulfilling genuine human needs. In this groundbreaking exploration of the power and future of gaming, McGonigal reveals how we can use the lessons of game design to fix what is wrong with the real world.