My advice would be to read Richard Bartles book, Designing Virtual Worlds at least twice before attempting to design an MMORPG. He covers all of the common recurring discussions and then some.  Besides, its an interesting and fun book to read, even if you're not designing an MMORPG or MUD.<p>I'd also suggest checking this out: <a href="http://mu.ranter.net/design-theory" rel="nofollow">http://mu.ranter.net/design-theory</a>