This book confronts a major institution of recent decades, neo-liberalism and its exaggerated pro-market views. It examines two of its Game Theory models: "The Prisoner's Dilemma" and "The Tragedy of the Commons". Both are shown to be basically unstable; they may change into several quite distinct games at any phase. Two examples of commons are examined in historical detail, the city commons of 17 c. Oslo and Trondheim. Numerous local cases are surveyed more summarily, as well as European similar cases. Finally, a brief mention of commons of the sea, air, subsoil, and of the Net. With author index and bibliography.