Wiktionary
magic circles
n. (magic circle English)
Usage examples of "magic circles".
But with that kind of energy to draw upon, once the balance is established between the magic circles and the electronics of the stabilization field, I'd rather not give that kind of a double-feedback loop too long to build up.
Taking a stump of chalk from his pocket, he drew on the red-tiled floor around the bed one of the Magic Circles, a precautionary measure against evils that Yirth, when she had taught him this one, had been unable to define clearly.
As he gave his testimony, he peered nervously at the two women held inside the magic circles.