The Book of Shadows is a collection of magical and religious texts of Wicca and other Neopagan witchcraft traditions, containing the core rituals, magical practices, ethics and philosophy of a Wiccan or other tradition. In the coven based British Traditional Wicca, it is traditionally copied by hand from the book of one's initiating High Priestess or Priest, who copied theirs from their initiator. In modern Eclectic Wiccan terminology, however, a Book of Shadows is a personal magical journal rather than a traditional text.
Within traditional lineaged forms of Wicca there are a number of versions of the Book of Shadows, their contents varying to a greater or lesser degree from the early versions belonging to Gerald Gardner, who first popularised Wicca. While Gardner seems to have originally treated the book as a personal journal, it has come to be considered a religious text in most traditions.
Gardner told his early students in the Bricket Wood coven that the Book of Shadows was a personal cookbook of spells that have worked for the owner; they could copy from his own book and add or remove material as they saw fit. Although his own book had been put together with the help of Doreen Valiente and included material from a variety of modern sources, (notably from Aradia, or the Gospel of the Witches and the writings of Aleister Crowley) it also included sections written in an antique (or mock-antique) style, including advice for witches brought to trial and tortured. Gardner claimed that these sections were genuinly historical in origin, and that witches had not been allowed to write anything down until recently, to avoid incrimination; when at last Books of Shadows were allowed, the rituals and spells had to be written in a jumbled manner to prevent any non-initiate from using them. More recent scholars however have doubted their authenticity.
It seems likely that Gardner told his three subsequent initiatory lines that the book should be copied word for word, and Wiccans descended from Eleanor Bone, Patricia Crowther and Monique Wilson have widely believed that the book was of ancient provenance. North American Gardnerians of the Long Island line allow covens to add rituals and teachings to the book, but nothing may be removed.
Some Traditional Wiccans keep two Books of Shadows: one book of core rituals which does not change, and from which new initiates copy; and another coven book for ritual use, which is different from group to group and may contain much added material. Such material is often traded between covens.
Some Wiccans keep a personal Book of Shadows in addition to that of their tradition. This is typically for individual use and is not passed on to one's initiates.
The term Book of Shadows is believed to originate with Gardner, who is said to have taken it from the name of a Sanskrit manual of divination through the length of one's shadow.
The 2000 sequel to The Blair Witch Project was titled Book of Shadows: Blair Witch 2, despite there being no mention of a Book of Shadows during the film, the title was seen as an attempt to capitalise on the Charmed series' established market.