6. Test Screenings Demanded More Voice-Over
Casino is jammed packed with voice-over. The opening of the movie lays out the backstory of its three key characters (De Niro, Pesci and Stone). Test audiences felt confused as to why we should care about these set of particularly hostile individuals, and demanded more voice-over.
This led Scorsese and Pileggi to write a collection of opening voice-overs, which mainly came from the huge collection of interviews Pileggi had conducted for research, and assigned voice-overs to the main characters which introduced them more openly and gave the audience a flavour of their hostile traits. Throughout his career, Scorsese has used voice-over with a sort of balls out approach. He never holds back once he's committed to the cause, yet, and most most importantly, Scorsese never over uses them. Also, Joe Peci's voice-overs in Casino are a thing of absolute beauty.