‘Let the audience add up two plus two. They’ll love you forever.’: The screenplay as a self- teaching system

A successful film could be described as a self-teaching system, which teaches you how to watch it as you watch. The story reveals itself through a series of observed behaviours about which the audience speculates. What are the underlying motivations and pressures which manifest themselves through these actions? As we watch we come up with theories and test those theories against our understanding of the unfolding narrative. This surely is what Billy Wilder meant when he gave as rule 7 in his rules of screenwriting what he claimed was a tip from Ernst Lubitsch ‘Let the audience add up two plus two. They’ll love you forever.’ (Crowe 1999: 168).