I used to play Dungeons and Dragons for about 4 or 5 years. More precisely I used to be the Dungeon Master (I generally sucked as a player). In high school I organized 100-150 for a three round D&D tournament (which was a fund-raiser for my church–they had a liberal pastor there apparently).
Truthfully I haven’t touched the game in 20 years although I recently bought the 3.5 books (DM’s Guides, Monster Manual and Player’s Handbook). I don’t have time to dig up the links, but apparently Gary Gygax had a protracted battle over ownership of the trademark, and independents have spun off with their own own version of Dungeons and Dragons (called d20) that allows modules to be created and published without the need for licensing. A sometimes commenter on my blog Preston Dubose is involved in Midnight Cellar, a Texas-based publisher of game modules and extras for various systems (including D20 D&D).
It’s funny. The game rules are extremely complicated, but the secret to D&D is that the players don’t need to understand the rules that well. They need merely to involve themselves in the story and their character (and contribute ideas to the other people in their party who do know the rules).