A holy symbol or unholy symbol is both a unique figurative representation of a deity, and a literal symbol of that god that is owned or worn by her followers. The term "holy" is generally applied to the symbols of benign or neutral gods, while "unholy" is used for those of evil powers. Certain devout followers of a god (such as clerics) must use a holy or unholy symbol to channel positive and negative energy. Certain divine spells also require a symbol as a divine focus for casting. A symbol can be made of any number of materials, including wood or silver.