This document discusses design for behavioral change. It defines behavioral change as using perceptual and cognitive biases to design environments that will intentionally affect specific behaviors. It discusses using Lewin's formula of behavior being a function of person and environment factors (B=f(P,E)) to influence behavior. It provides examples of how to increase motivation and ability to perform behaviors and introduces triggers to cross the action line and enact behaviors. The document emphasizes the need to consider different personas, map customer journeys, and validate ideas to effectively design for behavioral change.