Every story has a plot and a subplot. The plot is the main goal. The subplot is a related story that helps the hero change and be capable of achieving the main goal.
Take any good movie and strip out Act II. This leaves you with Act I, which introduces the hero and his problem, and Act III which shows the hero fighting to solve his problem and achieve a goal.
The main difference between Act I and Act III is the hero. The goal is still the same, but at the beginning of Act I, the hero has a goal but doesn’t have the ability to achieve it. In “The Karate Kid,” the hero wants to fight the bullies, but isn’t physically able to do so. By Act III, the hero is ready and now capable of achieving his original goal.
How does this change occur? It’s easy. It all takes place in Act II where the subplot teaches the hero the skills and lessons he needs to learn to be capable of achieving his original goal.
In “The Karate Kid,” the subplot is where the hero starts learning kung fu from his maintenance man and also pursuing a girlfriend at the same time. Act II is a detour that temporarily stalls the hero towards his original goal while teaching him lessons he needs to learn in order to achieve his original goal.
When creating your story, first focus on Act I and Act III. Act I should focus on highlighting a serious problem of the hero’s that the audience can understand and sympathize with. Act III is all about the hero struggling to achieve his goal.
Act II is all about how the hero changes and becomes powerful enough to reach his goal. Without a coherent subplot, the hero can’t learn the lessons he needs to ultimately succeed.
The breakdown of a screenplay works like this:
Act I — Introduce the hero, his problem, and his obstacles.
Act III — Show the hero confronting the villain.
Act II — Show how the hero gained the skills necessary to achieve his original goal.
In “Die Hard,” Bruce Willis’s original goal is to get back with his wife. However, it takes nearly being killed by terrorists for him to realize how much his family really means to him. That gives him the courage to defeat the terrorists and get back with his wife.
Strip away Act II and you should recognize a condensed version of your story. Focus strictly on Act II and you should see how the hero grows, learns, and changes into a better person.
By focusing on different parts of your story at any given time, you can avoid trying to cram everything into your screenplay in a disorganized fashion. Just focus on one part at a time and get your story structure firmly established. Then you should have a solid story that people will actually want to see that doesn’t rely on the fireworks-like display of special effects and explosions that too many films rely on instead of plot and character development.