Magic circle
A magic circle is circle (or sphere, field) of space marked out by practitioners of many branches of ritual magic, which they generally believe will contain energy and form a sacred space, or will provide them a form of magical protection, or both. It may be marked physically, drawn in salt or chalk, for example, or merely visualised. Its spiritual significance is similar to that of mandala and yantra in some Eastern religions.
Common terms and practices
Traditionally, circles were believed by ritual magicians to form a protective barrier between themselves and what they summoned. In modern times, practitioners generally cast magic circles to contain and concentrate the energy they raise during a ritual.
Creating a magic circle is known as casting a circle, circle casting, and various other names.
Techniques
There are many published techniques for casting a circle, and many groups and individuals have their own unique methods. The common feature of these practices is that a boundary is traced around the working area. Some witchcraft traditions say that one must trace around the circle deosil three times. There is variation over which direction one should start in.