the butterfly effect system is a storytelling mechanism for managing complex narrative structures where actions from the experiencer can have a direct influence on how the narrative plays out

The phrase ‘butterfly effect’ derives from chaos theory where American mathematician Edward Norton Lorenz used it as a metaphor to describe the phenomenon whereby a minor change in circumstances can cause a large change in outcome.

The idea has since been adopted by computer games like Until Dawn and Life Is Strange, where a literal butterfly icon has been used to signal that an action taken by a gamer has had a direct influence on the game’s narrative arc.

Until Dawn Butterfly Effect example