The GNS Theory, as originally developed by Ron Edwards, is a relatively amorphous body of work attempting to create a theory of how role-playing games work. Primarily, GNS Theory holds that participants in role-playing games reinforce each other's behaviour towards ends which can be divided into three categories: * Gamist behaviours reinforce competition and challenge * Narrativist behaviours reinforce story and theme * Simulationist behaviours reinforce experience and celebration of source material