This document discusses the possession horror subgenre and plans for a student film project exploring its conventions. It will focus on three characters communicating through an Ouija board, with flashbacks revealing how they become possessed. Key conventions that will be included are isolated settings like homes, the involvement of priests or mediums, and signs of possession like strange physical abilities. The project aims to both enforce conventions like using a family home and challenge them by subverting expectations of who becomes possessed. Inspirations include The Exorcist for its entrapment scenes, Ouija for its use of the board, and The Devil Inside for possessing the intended exorcists.