Whats this I hear about the d20 System? Is it the same thing as 3rd Edition Dungeons and Dragons?
Not exactly. 3rd Edition Dungeons and Dragons is a specific example of a game which uses the d20 System rules, but it’s not the only one. The d20 System rules are intended to be a system which can be used with any genre (Wizards of the Coast have already released their Star Wars game using the d20 Rules). Just because a sourcebook uses the d20 System rules, you should not assume that the contents will be entirely compatible with a Dungeons and Dragons game.