One of the biggest mistakes novices make when writing a screenplay is that they don’t give their characters any type of history. Study every good movie and you’ll notice that every story is about the main characters overcoming a problem from the past. In most movies, the hero overcomes problems from the past but sometimes the mentor needs to overcome problems from the past.
In “Die Hard,” the hero’s past is that he wants to get back with his wife. What we don’t see is how they broke up in the first place, but this desire to get back with his wife is the hero’s motivation from start to finish. He begins the story flying to meet his wife and get back together and in the end, he finally succeeds. Without this past, the story would literally have nowhere to go.
In some movies, the mentor has more of the past to overcome. In “Star Wars,” Luke is the hero, but his past is mostly about wanting to get off his boring planet and live an adventure. The moment he finally flies off his planet, he’s succeeded. Where the past comes back to haunt the story is through Obi-wan, the mentor, when he must face Darth Vader. Although we don’t fully understand what’s going on, we know that obi-wan made a mistake in the past and needs to redeem himself by facing Darth Vader.
Another movie that involves the mentor’s past is “The Karate Kid.” The hero’s past is relatively simple. He’s moving from one neighborhood to a strange neighborhood. However the mentor is hiding a past mistake that he finally reveals near the end. That makes the hero (and audience) suddenly understand the mentor better as a flawed character. Now we can better understand why the mentor wanted to help the hero because he wants to redeem himself in his own eyes and doesn’t want to see someone else get hurt unnecessarily.
Notice how knowing the history of the hero or mentor suddenly gives the story more emotional impact. There are two ways to tell the audience about the history of the characters. The first way is the traditional way of throwing the audience in the middle of the story and gradually leaking hints of the past until the truth is finally revealed near the end. That’s how “Back to the Future” works by showing the hero (Marty) dealing with his loser family and feeling like a failure himself. By going back to the past, Marty gradually learns how his parents became the losers that they were.
Another example of leaking information gradually is “Casablanca.” Here we meet the hero (Rick) who is cynical and selfish. Only when he sees his old girlfriend (Ilsa) does his past gradually leak out until the final flashback scene where we learned that Ilsa never met Rick to leave in the end and broke his heart. Suddenly we understand why Rick behaved selfishly earlier.
The formula for this first method is simple. Know your characters’ history. Gradually leak this history out until revealing it right before Act III.
The second way to explain the past is to actually show that history, then leap ahead. In “Up,” we get to see the hero as a kid, marrying his wife, dreaming of doing all sorts of adventures with her, then seeing her get sick and never fulfill her dream. Then the hero is left a bitter, old man. Now the story finally gets started.
“Cliffhanger” shows the hero trying to save a woman but failing. Now the story leaps ahead to where he’s a broken man who regrets his failure in saving an innocent woman.
You need a history for your main characters. You can either leak out that history until revealing it near the end, or show that traumatic event right away and then leap ahead to the future to show how the hero overcomes this traumatic event.
The point is that your characters needs a history. Without a history, you literally won’t have a story and your screenplay will likely run out of ideas before you’ll even finish.