Witchcraft is the art of invoking magical forces in order to manipulate worldly events. Commonly, a practitioner of witchcraft is called a witch. A witch can either be born as such (having inherited their powers from one or both parents), or they may acquire magical powers through practice. A witch who received their power from an ancestor is known as a natural witch. As Lirio explains it, a natural witch's power comes "from within".
Some witches abide by a code of ethics which forbids using magic for personal gain. Consequently, if a witch is to use magic selfishly or to harm others, she automatically invokes the Rule of Three, which indicates that whatever she sends out, she get back times three. Lirio explained that magic is neither black nor white: "It is both because nature is both. Loving and cruel, all at the same time. The only good or bad is in the heart of the witch." If a witch uses their power irresponsibly, they will lose their powers.
As a means of utilizing magical faculties, a witch may call upon a deity to perform their will. Sarah, Nancy, Bonnie and Rochelle often called upon Manon, who's mythology was never explained, but through context, he is suggested to be a powerful and wrathful sea god.
A witch may practice her craft solitarily, or with the aid of a coven. A complete coven is composed of four witches, each to represent the four elements: water, fire, earth and air, as well as their corresponding directions: north, south, east and west. When a coven is complete, members may invoke a rite known as Invoking the Spirit, which allows them to call upon a deity and invoke their energy. If a witch abuses the deity's power, she will grow more and more mentally unstable until reaching a state of complete delusion, as Nancy did.