Most of us have some idea about game theory. Concepts like zero-sum games and the prisoner's dilemma crop up in films, novels and casual conversation, often as shorthand for cut-throat competition or inevitable betrayal. But game theory, the science behind these ideas, is widely misunderstood. All too often it's seen solely as the science of conflict and greed. In fact, this field has a lot to teach us about how to make a better world. It shows us just what it takes to enable cooperation and mutual benefit.This essential primer presents twenty one 'life lessons from game theory', which illustrate the key ideas in the field, and which are packed with real world examples: from overfishing in the Atlantic; to the Cuban Missile Crisis; to security measures at international airports; to advertising wars between major brands. This is a hopeful and practical book that highlights the value of game theory and provides a course correction for its integration into the real world.