The name comes from the old word Gramarye meaning magic. Therefore the name speaks for itself, a Grimoire is a book of magic.

It contains instructions, invocations, rituals and ceremonies for conjuring or invoking spirits and demons as well as instructions for making powerful, magical amulets. Those outside the arts do not realize the Grimoire is deeply rooted in Christian piety. The arts inside the Grimoire often call upon God for help, protection and direction.

Many famous Grimoires are from the mid-15th centuries to the late 18th centuries seeing a revival of the Grimoire in the last 10 years. The information within Grimoires however is often hundreds and thousands of years older than the Grimoire itself. Information is passed through cultures, family, practitioners and friendships leaving many Grimoires a rich source of powerful material.

The most famous Grimoire of all time is the Key of Solomon, after it was circulated many Grimoires from that point on followed the Key of Solomon as a tried and true guide. It is thought however the detailed and difficulty presented in the Key of Solomon was to keep underprivileged practitioners from being able to complete any of the objections in the Key and rather to encourage an elite few who could actually perform the lengthy and confusing rituals. Since that point smaller versions of the Key have appeared and mostly in part rather than whole. A copy of the original Key in its entirety is extraordinarily rare.

The Key dictates the time, place, weapons, robes, pentacles and circles needed to conjure spirits and force their obedience. It is based on astrological and cabalistic magic. The intrigue of the detail of the Key spawned others to make Keys of their own. The most famous of these being the Lemegeton, the Grand Grimoire. It became nicknamed the Red Dragon because it explains in detail how to make a pact with the Devil. It also provides instruction for intimidating the spirits to make them "tremble". The True Black Magic nicknamed "Secrets of Secrets" is filled with a detailed collection of magic symbols and talismans. The Grimoire of Honorius the Great is a collection of Christian psalms and prayers to conjure the Devil.

Depending on the kind of magic a person practices depends on whether or not they truly have a Grimoire; a Grimoire, for any purpose, is always rooted in Christianity.