Life is often a matter of gambles, pay-offs and trade-offs, just like a game. This book takes the reader on a tour through the games and computer simulations that are helping science to understand the ecology, evolution and behaviour of real life - from cat and mouse to cellular automata, from the battle of the sexes to artificial life, from poker to the prisoner's dilemma. It explains why scientific observations and insights can be structured as the rules of a survival game, and what happens when they are assembled on a computer or in the mind and allowed to run. The book looks at genetics, population ecology, evolution and animal behaviour.