Narrative theorists Tzvetan Todorov, Vladimir Propp, Claude Levi-Strauss, and Roland Barthes developed theories about the structure of narratives in films and documentaries. Todorov theorized that narratives follow a pattern of equilibrium, disruption of equilibrium, and restoration of equilibrium. Propp identified eight character roles that commonly appear. Levi-Strauss said narratives are built from binary oppositions such as good vs evil. Barthes saw narratives as consisting of codes that control what the audience sees and present puzzles for them to solve.