An essential text that has already become a classic, addressing the issues arising in MMORPGs and MUDs, most of which apply directly to the fundamentals of the more recent 'goal-free' worlds such as Second Life. Castronova writes as a senior economics academic, and deals with all the relevant issues of the synthetic world economy and its relationship to the non-synthetic world. Along the way he successfully establishes and defends a position that asserts the mutual interpenetration of synthetic and non-synthetic worlds, based on the widely-accepted utility (subjective) definition of the value of goods and services offered in a marketplace. Thus, an artefact created within Second Life and sold for the same final bid alongside non-synthetic articles on e-Bay is as real and as valuable as they are: within the economist's definition of value, identical. Text 283pp, Appendix 10pp, Notes 16pp, References 7pp, Index 14pp. It could have been dry but it is emphatically not so; a fascinating account, told with humour and insight.