It is argued in this paper that the closed world of computer simulations and nuclear games which Edwards describes is an imaginary place. Indeed, Edwards’ closed world is a caricature of the real world of Cold War and American nuclear strategy. His account of the imaginary world and its development draws on and perpetuates the folklore of Cold War and American nuclear strategy. The folklore, which fails to acknowledge the frightening realities of the strategy of nuclear deterrence, has achieved a high level of academic respectability in the United States and elsewhere. Even though Edwards does not simply accept the folklore chapter and verse, enough of it survives intact in his book to leave his history of computers in the Cold War wanting at key stages and in important respects. Because he likens nuclear war to a computer game, he seriously underestimates the grave risks and dangers that accompanied American preparations and planning for nuclear war with the Soviet Union. In the end, Edwards trivialises the deadly serious business of nuclear war planning and preparation.