In his book, Plot and Structure, (see the link in my previous post), author and speaker, James Scott Bell, offers this definition of his terms.  Plot concerns the elements of a story, what happens.  Structure is about the timing of those events – when they happen.

The Three Act Structure is the default of storytelling and has been, according to Bell, at least since time of Aristotle.  A novelist doesn’t need to use it, but like an oil painter who decides to forgo a flat, rectangular surface, it is good to know what you are doing instead.

Screenwriters don’t even have the choice to stray.  So pervasive is the influence of Syd Fields, a champion of the three act structure in movies, that studios often specify it in their contracts.  (See the link to Syd Fields’ Screenplay in this post ( https://thefirstgates.com/2010/08/26/a-novel-planning-method/ ).

Every writer about writing who discusses what belongs in the Beginning, Middle, and End is implicitly endorsing what Bell and Fields refer to as Act I, Act II, and Act III, but both of these writers offer more detailed terminology that helps flesh out the concept.  Setup, Conflict, Resolution are Fields’ terms.  I once heard a screenwriter use those exact words to describe what you need to pitch to a producer in the three sentences or so they are willing to listen to.  Literary agents give similar advice.

Bell and Fields offer nearly identical diagrams of the three act structure:

The thing to notice here is the timing.  Act I, the Setup, where we meet the protagonist(s), their problem, and their world lasts for about a quarter of the story.  Act II, the trials and tribulations lasts for half of the novel or movie, and Act III, which often includes a final battle or chase, takes up the last quarter of the manuscript.

Syd Fields uses “Plot Point” to signal the dramatic event that bridges two of the Acts.  I prefer Bell’s term, “Doorway of No Return,” because usually the previous world is swept away, and going home again is no longer possible.  Neo chooses the red pill.  Louise shoots a man.  A rider interrupts the party at Tara to announce that the Civil War has begun.

It’s fun to watch for the moment this happens in movies, since the timing tends to be very precise.  In a two hour film, something will occur very close to the half-hour point that locks the hero into the conflict – he cannot go back to the Shire.

The second Doorway of No Return, about three-quarters into the film or novel, guarantees the final showdown.  Gary Cooper watches the last train pull out of town, and it’s almost noon.  When he and Trinity rescue Morpheus, Neo really believes, for the first time, that he is “The One.”  In True Grit, Maddie sees the man who shot her father at the river.  He does not notice her.  She could slip away, but once she draws her pistol and orders him to surrender, the final battle is underway.

As I said in my previous post, I find a lot of useful suggestions in James Scott Bell’s Plot and Structure, including the clearest discussion I know of the Three Act Structure.  Still, thanks to Google, you don’t need a book to gather a lot of good information, including suggestions that the Three Act Structure is passe, an impediment, or a device for mere genre-writers.   We can use it or not but it seems to me that any writer can benefit from understanding the concept.