The Ouija board is a flat board marked with letters, numbers, and symbols, used for divination or communication with spirits. Participants place their fingers on a planchette, a small heart-shaped piece of wood or plastic, which is believed to move to spell out messages. The board gained popularity in the late 19th century and is often associated with spiritualism. While many people view the Ouija board as a fun party game, others take it seriously as a tool for contacting the supernatural. Skeptics argue that the movements of the planchette are due to the ideomotor effect, where unconscious muscle movements guide it, rather than any paranormal influence.