Anathema cut a mortal away from all favor from the caster's and target's shared patron deity, no matter the distance between the two, and the target was forever affected. The target could not benefit from the patron deity in any way. For example, if the target was a divine caster, they lost all supernatural benefit associated with the deity, like spellcasting or the ability to channel energy in the form of turning or rebuking undead. While the target was alive, he or she was not allowed to access any services like weddings or funerals of the patron deity's faith and fellow worshipers were not allowed to acknowledge the existence of the target. Clerics, druids, paladins, and rangers of the faith of the target could supernaturally distinguish a person under an anathema effect by sight, while lay-members needed to be informed by people who could distinguish the pariah. When the target died, he or she was considered Faithless and was part of the Wall of the Faithless.
Only the caster or a divine spellcaster who was stronger than the caster could dissolve an anathema and rehabilitate the target. An atonement was necessary if the latter method was chosen. A third method to get rid of an anathema was to switch deities.
To cast anathema, somatic and verbal components were needed. Additionally, a divine focus and another focus in the form of a book or scroll was needed, which remained in existence on casting. The focus needed to be specifically sanctified for the casting of an anathema spell. The content of the book or scroll were two things: the name of the target and the crimes of the target that made the target eligible for an anathema. Said crimes could be made-up ones.
Anathema was considered the most fearsome of divine curses by the 14th century DR. A few deities put some strictures on its use. For example, some deities did not want innocents to be the target of this spell, others forbade their priests from targeting their chosens, while others had a very liberal policy regarding the use of this spell.