Shar, the Mistress of the Night, is the goddess of darkness and caverns of Faerûn, as well as a neutral evil greater deity. Counterpart to her twin Selûne, she presided over caverns, darkness, dungeons, forgetfulness, loss, night, secrets, and the Underdark.

The clergy of Shar were a secretive organization that pursued subversive tactics rather than direct confrontation with its rivals.