Fantasy novels need rules. For fantasy, the big one is “How does magic work?”
That question literally supplied the plot of my first two novels. And the one I’m working on now.
Someone at Gizmodo has assembled a list for us: Rules of Magic.
The Coffee House Writers Group is a writers group in the Los Angeles area designed to support writers through critique groups, presentations, and social events. I go to their Wednesday Meetup in Long Beach, CA.