The central conflict of Back to the Future is clear in the film’s title. Marty McFly needs Doc Brown to fix the time machine to get back to the future. This simple conflict plays out over the course of an hour and a half and can teach us a lot about writing conflict.
You may be familiar with the KISS-methods of storytelling. KISS stands for Keep It Simple, Stupid. Don’t over-complicate things that otherwise need not be.
However, simple isn’t always better. In Back to the Future, the simple conflict is fine. Marty needs to get back home. But that simple conflict wouldn’t drive the entire film. It’d be boring.
The film’s writers brought in several sub-conflicts that feed off the main conflict. When Marty arrives in 1955, he messes up history as he knows it. Besides trying to get home, Marty has to fix all the problems he caused. These conflicts drive the story forward.
At the climax of the film with all of the sub-conflicts solved, it’s time for Marty to go home. Following the KISS-method, Marty would get in the time machine and head back to 1985. Thankfully, the writers threw the KISS-method out the window.
Doc Brown has to reconnect electrical conductors twice. Marty, having to simply drive the car when the alarm goes off, can’t get the DeLorean to start. These little conflicts go against the KISS-method but make the story much more interesting.
When writing your own conflict into stories, don’t be afraid to add sub-conflicts that build from the central conflict of the story. As Back to the Future shows, the added suspense of the car not starting could be enough to add a dramatic kick to the story.