What makes every story richer and deeper are subplots. A subplot is a mini-story within your story, but you absolutely need one in your story and here’s the reason why.
Every story is about a hero battling a villain. If that was all your story did, it would get dull very quickly. Your hero confronts the villain and either wins or loses. End of story. To make your story more interesting, you need subplots.
After you establish your story, your hero, and your villain in Act I, you need a subplot to complicate life for your hero. A subplot has two purposes. First, it needs to throw additional obstacles in the hero’s path. Second, it needs to reiterate the story theme.
In “Die Hard,” the main story is Bruce Willis fighting the terrorists so he can get back with his wife. A subplot is one of his wife’s co-workers trying to pick up Bruce Willis’s wife. This causes another obstacle in the hero’s path.
Another subplot in “Die Hard” is the FBI. They try to take over the police response and botch the effort, once again providing another threat to the hero.
In “Ratatouille,” Remy the rat’s main problem is to be able to cook in the kitchen. A subplot that threatens him is when the boy chef falls in love with the female chef, threatening Remy’s position in the kitchen. Another subplot is when the short chef tries to expose Remy. Still another subplot is the food critic trying to destroy the restaurant’s reputation.
Subplots are miniature stories that reiterate the basic story theme and throw one more obstacle in the hero’s way. Sometimes the subplot’s villain turns out to be an ally, such as in “Avatar” when the other warrior eventually becomes the hero’s friend or the boxing coach in “Rocky” who eventually helps Rocky after trying to throw him out of the gym earlier when he thought that Rocky was washed up.
Other times the subplot’s villain remains another villain, such as the short chef in “Ratatouille.” Sometimes a subplot character may seem to be a friend but turns into a villain, such as the hitchhiker in “Thelma and Louise” who steals their money.
To create a subplot, you must first define what your main story is about. Then in Act II, introduce additional complications (subplots) that further interfere with your hero. Subplots aren’t just random stories, but stories that block the hero’s progress and reiterate the overall story’s theme.
In “Die Hard,” the subplots all revolve around Bruce Willis trying to get back with his wife. Her co-worker who tries to hit on her poses one problem while the clumsiness of the FBI poses another by threatening to kill her and some of the hostages. Introducing a subplot that doesn’t threaten to keep Bruce Willis away from his wife is pointless.
Subplots add texture and depth to your main story. In a short story, you don’t need subplots, but in a longer story such as a novel, stage play, or screenplay, you need subplots to avoid focusing on your hero and villain too much. The more villains your hero can overcome, the sweeter the ultimate victory will be.