A devil's trap is a symbol used in mysticism to contain and control demons. Once a demon enters a devil's trap, it is unable to exit.
A devil's trap is drawn as a star enclosed in a circle. It can take the form of a pentagram, a five-pointed star, or a heptagram, a seven-pointed star. A devil's trap is considered stronger and more lasting than another form of demon trap, the salt circle. A devil's trap loses its power if its lines are erased or partially erased. The circle must remain intact in order to keep the demon trapped inside.
Devil's traps are described in the 17th-century text "The Lesser Key of Solomon." This text is a grimoire, or book of spells, that focuses on demonology. It consist of five books, and although it was purportedly written by King Solomon, its author is unknown. The books collect information from earlier texts, some of which date to as early as the 14th century. "The Lesser Key of Solomon" includes a list of the 72 existing demons, all of whom have titles such as "King," "Duke," "Prince" and "Count."
"The Lesser Key of Solomon" has been referenced in supernatural fiction, including the television shows "Supernatural" and "Sleepy Hollow." Both shows focus on protagonists who frequently battle demons.