10 Of The Greatest Ad Libs In Film History

Casablanca

Humphrey Bogart and Ingrid Bergman in an iconic scene from the 1942 film 'Casablanca.' Photo: Photo: Popperfoto/Getty Images

For any great actor, a character is so much more than a part to play. Once filming starts, many of them—quite literally—transform into their role and the script becomes negotiable.

Here, 10 of the best ad libs in film history.