The other part of magic you need to know is magic-circle theory. Most magic involves a circle of one kind or another. Drawing a circle sets a local limit on what a wizard is trying to do. It helps him refine his magic, focus and direct it more clearly. It does this by creating a sort of screen, defined by the perimeter of the circle, that keeps random magical energy from going past it, containing it within the circle so that it can be used.
