All plays, whether on the screen or on the stage, have a format more defining than any other form of literary expression. Screenplays are, perhaps, the toughest. They have a structure as steely and rigid as the support towers of the Golden Gate Bridge. They are more restrictive than the Japanese seventeen-syllable, set-in-concrete poem known as haiku. The best comparison is to picture a novel a vat of mushroom soup, and a screenplay as a stock cube, same intensity of flavor, but powerfully compressed. If writing a novel is swimming in the ocean, screenwriting is swimming in the bath.
Every story must have a beginning, must have a middle, and must have an end. And don't think you can write it until you know what that end is. These elements can also be called set-up, conflict and resolution. You can dance around this formula until you're blue in the face, but you're always going to come back to it. Set-up. Conflict. Resolution. That's the way it always has been. That's the way it always will be. And the key to screenplay structure is hitting the right page with the right beat.
Set up. Conflict. Resolution. Act I, Act II, Act III. Scripts are mathematical. Structuring them is a numeric problem. They are meticulously engineered; yet must disguise their geometric precision.
Act II is so long — 60 pages — it must be divided in half to create Act II A and Act II B, which leaves four Acts. Plain and simple. But the trick is to split Act II at the central turning point of the entire movie. This can sometimes be called the flip-the-script moment, or the mid-point, and it happens exactly halfway through all movies. This turning point in the drama must be established long before you begin writing. And it must take the audience from Act II A into Act II B.
Each Act should be 30 pages. Four of those make 120, the Hollywood length. Act I, II A, II B and III. But, unlike the theatre that has a curtain to divide Acts, or television dramas where they are consistent with commercials, how can you tell when an Act has changed in the cinema? Being able to spot this, and understanding why Acts change, and grasping what each Act must achieve is something you must master.
This introduces the main characters, establishes 'the rules of the world', and sets-up the hero's goal for the rest of the movie. But this can't be an arbitrary decision. In all great scripts, there lies within Act I the Inciting Incident. This is the event, usually found on page 10-15 that sparks the desire your hero needs in order to pursue his goal. When you study films, it can be identified easily. Watch out for the event that occurs in the hero's life that doesn't happen every day. This is the Inciting Incident.
Act I ends on page 25-30. Study opening scenes from films you know. Why have they chosen to start this way? How does this opening reveal character, introduce the hero or nemesis? The opening to a movie must be chosen carefully. The Incident that sparks the story, must, above all, be credible. Not some cockamamie idea that will cause everyone in the cinema to say, "Yeah, right!"
Act II A
The hero begins his journey. It must be filled with conflicts and obstacles that are constantly being thrown in his way. The trickiest part is inventing that turning point on page 60. It must change the course of the story, yet keep the hero pursuing the same goal. A great example is in Derailed. At the end of Act II A, Clive Owen suddenly realizes Jennifer Anniston is no longer the sweet blond with a bad marriage, but his real nemesis. You must come up with something that will literally turn the script around, making the audience gasp. This turning point is so critical you may want to structure the entire story around this one event. Watch films and identify this point. A History of Violence contains another great example.
Act II B
At the beginning of this Act, a ray of hope must shine upon the hero. With his original goal from Act I, and with the drama now aimed in a new direction, conflicts must start again, sliding towards the low-point, where the hero reaches an all-time low. This must happen on page 90. It marks the end of Act II. It's the now-or-never moment, and everything you write is aimed resolutely towards this point. You must keep telling yourself, "I've got to get my hero to the page 90 abyss in the next x amount of pages." You'll find it easier to work backwards. That will stop you over-shooting and ending up page 96, which makes Act II B too long, too long, too long. Then you've got to cut it, which is even more difficult than writing it.
This contains two parts. The final battle with the nemesis, where the hero achieves his goal against all odds, and then, the long awaited resolution - only a few pages long. The end of the script is the most important part. You must know where your hero is going before you write one word of the script. You write towards the end. This will allow you to plant and foreshadow the drama. You cannot operate until the end has been established. If you start writing without knowing the end, you will fail, probably catastrophically.
Mastering this information.
Once you know the basic story, spend the next five hours trying to work out the last two minutes of the movie. Then you can begin to establish the low-point, moving backwards to the much more tricky mid-point.
The easiest Act to write is the first, because it's an introduction and establishes the Goal. However, Act I requires diligent research and more detail than any other part of the script. Act II is very hard, and this is where almost every script fails, leading up to the turning-point. And if you feel this is going wrong, you might as well turn off your computer and start again.
Ultimately, you live and die between page 30 and page 60. It's a four Act structure, no ifs, ands or buts. Keep the reader or audience hooked, load in the surprises, and no goofing off cruising through three or four pages without much happening. You can't afford it in screenwriting.
Watch films with all these points in mind. Pay attention to Act breaks, (time them on your watch — about every half hour). Count the conflicts being hurled at the hero. Watch how the nemesis always seems more powerful. This is the making of a hero. He must overcome the seemingly insurmountable struggle to achieve his goal.
Thrillers, action films, Westerns and horrors are great genres to grasp these principles. High Noon, The Wizard of Oz and Star Wars all possess the geometric precision I have outlined. The watchword is structure. And it's as critical to your writing as those towers that hold up the Golden Gate Bridge.