Cinematic tradition suggests that Hollywood films, like plays, are divided into acts. Thompson (1999) streamlined the conception of this largescale film structure by suggesting that most films are composed of four acts of generally equal length—the setup, the complicating action, the development, and the climax (often including an epilog). These acts are based on the structure of the narrative, and would not necessarily have a physical manifestation in shots and transitions. Nonetheless, exploring a sample of 150 Hollywood style films from 1935 to 2005, this article demonstrates that acts shape shot lengths and transitions. Dividing films into quarters, we found that shots are longer at quarter boundaries and generally shorter near the middle of each quarter. Moreover, aside from the beginnings and ends of films, the article shows that fades, dissolves, and other non-cut transitions are more common in the third and less common in the fourth quarters of films.