Todorov theorized that narratives follow an equilibrium-disequilibrium-new equilibrium structure. Propp identified 31 narrative features and 7 character types that commonly appear in stories, including the villain, donor, helper, princess, false hero, dispatcher, and hero. Strauss proposed that conflict drives narratives and they can only end once conflict is resolved, often using binary opposites to create more conflict. Barthes referred to the "enigma code" where clues are given in stories without resolving the overall story, keeping the audience engaged.