The central tradition of mainline economics deals with one way of making a living; producing goods and services. But there is another way of getting ahead through conflict or the ‘dark side’, by appropriating what others have produced. Parallel to military aggression and resistance, the dark side includes non-military activities such as litigation, strikes and lockouts, takeover contests, and bureaucratic back-biting struggles. This volume brings the analysis of conflict into the mainstream of economics. Part I explores the causes, conduct, and consequences of conflict as an economic activity. Part II delves deeply into the evolutionary sources of our capacities, physical and mental, for both conflict and cooperation. The introductory chapter of the volume, which outlines the significance of the dark side, was the author’s 1993 Presidential Address to the Western Economic Association. Other chapters investigate economic models, historical discussions, experimental tests, and applications to topics in political science and law.