Field's most important contribution has been his articulation of the ideal "three act structure". In this structure, a film must begin with about half an hour of 'setup' information before the protagonist experiences a 'turning point' that gives him or her a goal that must be achieved. Approximately half the movie's running time must then be taken up with the protagonist's struggle to achieve his or her goal: this is the 'Confrontation' period. Field also refers, sometimes, to the 'Midpoint', a more subtle turning point that should happen in the middle (approximately at page 60 of a written screenplay) of the Confrontation, which is often an apparently devastating reversal of the protagonist's fortune. The final quarter of the film depicts a climactic struggle by the protagonist to finally achieve (or not achieve) his or her goal and the aftermath of this struggle.Plot point 1 occurs at 30 minutes, Plot point 2, at 90 minutes. Simple!
That paradigm has undergone rigourous changes throughout its first inception, providing us with a slightly more flexible situation in which we have a set of demarcations that help better define the Acts and moreoever, the plotting of the story itself.
Now we have a Midpoint that separates Act 2 in two - actually giving us a 4 Act piece (but let's not worry too much about throwing that idea around). We have an Inciting Incident that occurs in Act 1 (could be the first 10 minutes, or at Plot Point 1). And at the end we have the Epilogue (in which loose threads may be tied up - how will our protagonist exist in their new world?) - it's important to keep in mind that this isn't rigid, and these points may be slid up and down the scale to fit the story being told. Famously, Callie Khouri decided against writing to Syd Field's formula because she found it too rigid, and yet when he released an analysis of four films that adhere to his structure, Callie's Thelma and Louise came first.
Then, we have two other unique events - the Pinches. These provide Act 2 with more punch. Things that help the plot further progress.
Finally, right at the front, is the 1st 10 Minutes. And why is this important? Because the writer needs to jam a whole loads of information in there so that the reader/audience can get an understanding of what's in store for them: characters, genre, plot, tone, etc.
This, thus, gives us, if you count the demarced zones, perhaps 9 Acts (crazy notion), but this helps with advert breaks!
Applying this to our first week's film: Thelma and Louise:
- Act One - We meet the characters, setting up who they are and that this is a road/buddy movie.
- Inciting Incident - Hal attempts to rape Thelma. Louise rescues Thelma through the threat of violence. They have a chance to walk away, but Hal antagonises Louise and she shoots him dead.
- Plot Point 1 - Louise explains to Thelma that she's going to Mexico, that the cops won't believe that Hal was trying to rape Thelma and that Louise intervened, because they could have got away without shooting him. Louise feels she has no choice but to flee to Mexico and evade capture
- Act Two - The situation gets darker, but our characters develop from the seeds sown in Act One. Their greatest challenges and the point of no return are coming.
- Pinch 1 - Thelma and Louise meet JD, a young drifter, who catches Thelma's eye, and though Louise knows the last person they need to tag along is JD, she finally agrees to Thelma's wishes.
- Midpoint - Having slept with JD, Thelma goes to brag to Louise (she's growing up), only for Louise to ask after the $6,500 (Louise's life savings) that her boyfriend had wired over. They go to the room. JD is gone and the money with him (Thelma is still a kid). Louise breaks down. All is lost and finally Thelma takes charge of the situation (perhaps she is growing up).
- Pinch 2 - Captured by the cops, JD explains that Thelma and Louise are going to Mexico.
- Plot Point 2 - Louise points out to Thelma that they have two things going for them. 1) The cops don't know where they are, and 2) The cops don't know where they're headed. The cops let slip to Louise on the phone that they know where she's going, and then, because she's on the phone too long, they manage to trace her call. Thelma and Louise make the decision to go for Mexico, rather than hand themselves in. This is their last chance to turn back.
- Act Three - The journey is about to end. The girls are awake to the world, but Louise's act of shooting Hal in the inciting incident can't go unpunished...
- Epilogue - Thelma and Louise doesn't lend itself to an epilogue. The frame fades out before their car begins to plummet (a happy ending? They have gone out on their own terms, after all), and there can be no further resolution. There is a brief montage of them together, setting out on the journey, however.