Here are the official rules, please try to read everything.
To register, post a link to your homepage and your "comfort zone" in the themes category. Make sure the link works. Everyone (who registered) will be divided into four "free-for-all" groups, and the top two winners of those groups will face off with each other. The winner of that is the overall winner. You have to build one of the categories in themes, which will be randomly assigned to you. You will not have the same theme as your group members. You will be judged on how well you demonstrate your assigned theme. Brickarms, Brickforge, and rubber bands are allowed, but wood, paper, clone brands, glue, and cutting lego are not. LDD is not allowed either.
You may be disqualified if:
You break a rule.
You lie about your "comfort zone"
You post something unrelated.
You are a bad sport.
You lie about what you built (saying space fits under castle).