Everybody's heard of tabletop role-playing games (RPGs), but unless you've actually played one you probably don't know how they work. You know RPGs have something to do with nerds sitting around a table pretending to be elves and rolling funny dice, but the details are a little fuzzy. Even if you're an experienced RPG player, most game manuals spend more time explaining rules and genre trappings than offering practical advice for first-time Game Masters. Whether you're a wannabe gamer who's never rolled a twenty-sided die or a long-time player who's decided to take the plunge and run your own...