The Pentacle is used to summon any and all spirits from The Other Place (though later on experienced magicians are able to re-summon bound demons by using hand signs, words, or other such techniques). The summoner draws two pentacles, usually a large one for the spirit, and a smaller one for the magician to stand in. The pentacle itself acts as a restrictive mechanism against the spirit assaulting or otherwise harming their summoner, and gives the magician power over the spirit. Minor spirits, such as imps, sprites, and moulers, require simplistic pentacles with little to no reinforcing devices (candles, herbs, &e.), where as higher level spirits such as Djinn, Afrits, Marids, and the lofty, mysterious beings above them, require heavily complicated pentacles and incredible numbers of reinforcing devices.
The pentacle, in order to work, must be absolutely, or at least near enough perfect. One or two extremely minor mistakes have been shown to not be fatal, though as the level of spirit summoned increases, so does the risk. The two cases of this are as follows:
- Kitty Jones: When summoning a Succubus, she apparently made a minor error, and the spirit tried its luck. The spirit was destroyed however, the rest of the circle's protection kicking in, and burning the spirit to death.
- Julius Tallow: Tallow, making a minor error thanks to an intentional typo in one of his magical books, attempted to summon a powerful entity, possibly an afrit or a marid. The being, upon appearing, spotted an error in the circle, blasted aside the reinforcing devices, and leaked out of the "hole" and consumed him.
The pentacle is not required to keep the spirit in this realm, however. It is perfectly possible to keep the spirit on Earth without any restrictions or charges, though originally the spirit must be summoned via a pentacle. (The only instance of this occurring however was during Ptolemy's age in Egypt, by Ptolemy).
Aside from summoning the entity, the pentacle is used to bind the spirit to a charge, or to keep it in this world after it's charge is complete, or even to confine it to the world after the death of the magician, which would usually despell the entity.