This thesis explores economic aspects of virtual worlds by focusing on a specific massively multiplayer online role-playing game, RuneScape. In particular, it examines the similarities and differences between the virtual economics and real world economics, the economic understanding of RuneScape players and the possibility of using virtual worlds as a laboratory for testing economic behavior and theory. This thesis uses a versatile methodology that includes texts, direct observation, self-reports, and other reports to investigate the research questions. Virtual economics in general and RuneScape in specific are understudied so far and this study fills a gap in the literature. The unique contributions of this thesis are: a comprehensive survey that reveals player perceptions of economics, a new equation useful for modeling money supply, and a new use of faucet-drain economy in massively multiplayer online games. The results indicate that virtual economics of RuneScape partially reflects real world economics, player perceptions of virtual and real world economy are surprisingly complex, and virtual worlds can be used to study real world economics. Game developers, players, economists, educators, researchers, and individuals who are interested in massively multiplayer online games and economy in general can benefit from this study.