You can divide every story into four parts: Act I, Act IIa, Act IIb, and Act III where each Act is roughly the same length. In a two-hour movie, each Act is roughly 30 minutes in length.
This is the purpose of each Act:
- Act I – Exposition
- Act IIa – Positive rising action
- Act IIb – Negative rising action
- Act III – Climax
Exposition introduces the hero and what the story is about and the world where it takes place.
Positive rising action shows the hero gradually learning about a new world until finally achieving a notable goal of some kind. In “WALL-E,” this midpoint is where WALL-E finally reunites with Eve, the robot he’s in love with. In “Avatar,” this midpoint is where the hero finally makes love to the native girlfriend.
Negative rising action shows the hero’s world slowly falling apart because the main problem still hasn’t been solved and the hero hasn’t changed. This part of the story is where the villain gets stronger and the hero gets weaker.
The climax is where the hero fights the villain to determine who wins, once and for all. In most cases, this is a happy ending where the hero changes into a better person, but sometimes the hero changes into a worse person, which is a tragedy.
Another way to look at each Act is with the four D’s:
- Act I – Desire
- Act IIa – Deception
- Act IIb – Discovery
- Act III – Destiny
Desire introduces what the hero (and villain) want. This puts them on an eventually collision course.
Deception occurs when the hero enters a new world but still retains his or her old way of life. This lets the hero experience a new life without changing. In “Tootsie,” the hero must hide the fact that he’s a man pretending to be a woman. In “Avatar,” the hero is still a human but he’s running around in an avatar of an alien being.
Discovery occurs when the hero learns the villain’s goal and finally realizes the truth about his or her fatal flaw. In “Die Hard,” the hero learns that the villain plans to blow up the hostages on the roof to escape while also finally admitting to himself that his own arrogance broke up his marriage with his wife.
In “Top Gun: Maverick,” the hero finally realizes that he can’t protect his best friend’s son by stopping him. That’s when he realizes he must allow his best friend’s son to go on a dangerous mission where he could be killed.
Destiny defines what happens when the hero finally makes a decision and changes for good. This is where the hero takes a chance to trust him or herself to face the villain. In “Star Wars,” this is where Luke decides to attack the Death Star. In “Titanic,” this is where Rose fully commits herself to Jack. In “Top Gun: Maverick,” this is where Maverick chooses his best friend’s son to go on a dangerous mission.
Act III shows us the destiny of the hero. Did they win? (Most likely.) If not, what happens when they lose?
So think of Desire, Deception, Discovery, and Destiny as ways to help you outline your screenplay. When you can get clear on the purpose of each Act using the four D’s, it can help make writing your entire story much easier.