What structure to use for a screenplay is often the topic of fervent discussions.
Most movies – both successful and unsuccessful – adhere to a three act structure that goes way back to Aristotle who observed that stage plays in ancient Greece have a beginning, a middle and an end with distinct functions for each of these components.
Syd Field was one of the first authors to speak of three acts in a screenplay. He receives credit for being the first one to lay out these rules for movie scripts. In his book Screenplay he outlines functions of these three acts.
Currently the three act structure appears to be the standard that professionals look for when assessing the quality of a movie script. That alone suggests that it’s the format of choice for aspiring screenwriters.
Plus, a good story still needs to be well told and three acts as outlined below are a good way to do that. I’ll compare here the rules/approaches/paradigms laid out by three major names in the movie business - Syd Field, Robert McKee and Blake Snyder.
Syd Field is considered one of the gurus of screenwriting. Not everybody seems to like his views but I still recommend reading some of his books. The best start probably is Screenplay. I also appreciated The Screenwriter’s Problem Solver. It alerts you to many quality issues of movie scripts and it’s good to read it before you run into one of them.
That said, you shouldn’t settle for any one of the books mentioned here. If for some reason you must, then choose Story by Robert McKee. (All my opinion, of course.)
Many people in Hollywood are said to swear by Save The Cat by Blake Snyder. It’s worth a read. However, I don’t agree with it’s subtitle that it’s ‘The Last Book on Screenwriting You’ll Ever Need.’ At least not if it’s your first.
I’ll quote Blake Snyder’s beat sheet and add some explanations.
Syd Field and the three act structure
The statement that a good play consists of three acts goes way back until Aristotle who observed this fact in stage plays in the amphitheaters of ancient Greece. Aristotle spoke of a beginning, middle and end - parts of a play that have very specific purposes. Field made it more concrete when he spoke of three acts which should cover 25%, 50% and 25% of a script, respectively.
In his books he assumes a maximum length of 120 pages for a well done script. Make that 110 or less nowadays and adjust the percentages accordingly.
Here the table: