GNS theory is an informal field of study developed by Ron Edwards which attempts to create a unified theory of how role-playing games work. Focused on player behavior, in GNS theory participants in role-playing games organize their interactions around three categories of engagement: gamism, narrativism and simulation.
The theory focuses on player interaction rather than statistics, encompassing game design beyond role-playing games. Analysis centers on how player behavior fits the above parameters of engagement and how these preferences shape the content and direction of a game. GNS theory is used...