If you're interested in in-game economics, another very interesting read is Lessons From Habitathttp://www.fudco.com/chip/lessons.html, a game created in the early 80's by Chip Morningstar and F. Randall Farmer that ran on Commodore 64.
Despite being written more than two decades ago, most of the conclusions from Lessons.. are still fresh and applicable to game mechanics today.
Randall (@frandallfarmer) is also the author of Building Web Reputation Systems, published by O'Reilly - http://www.oreillynet.com/pub/au/3900. Another nice reading, if you're interested in the subject.
Despite being written more than two decades ago, most of the conclusions from Lessons.. are still fresh and applicable to game mechanics today.
Randall (@frandallfarmer) is also the author of Building Web Reputation Systems, published by O'Reilly - http://www.oreillynet.com/pub/au/3900. Another nice reading, if you're interested in the subject.