In a bad movie, the hero must constantly battle against obstacles that serve only to provide mindless action such as gunfire, explosions, and car crashes. There’s nothing wrong with action, but action needs to be rooted in attacking and pressuring the hero to change. You don’t want random obstacles to confront the hero. You want unified obstacles that are simply variations of the same basic threat to the hero that force the hero to eventually change.
For example, in “Titanic,” the biggest threat to the hero (Rose) is that she feels trapped by being pressured to marry a man she doesn’t love and live a life she doesn’t want. So every obstacle is about forcing her to change.
Rose starts out defeated and depressed. By the end, she’s independent and confident. Until the end though, Rose must face numerous obstacles from avoiding the man she’s supposed to marry (a bully) to staying alive on a sinking ocean liner. Yet all of these obstacles constantly threaten and force Rose to change. Rose’s initial reaction to her circumstances is to commit suicide. Then she tries to hide her feelings towards Jack, her friend and eventual lover. Finally, she needs to save Jack. All of these obstacles don’t exist just to show action, but to force Rose to constantly face a choice: submit to her life or decide to define her own life.
In “Back to the Future,” the hero (Marty) lacks confidence in himself. Now every obstacle he faces forces him to either give up and accept his fate or shape his future. The first obstacle he faces is when terrorist kill Doc. Now he has a choice of either getting killed as well or jumping into the DeLorean time machine and escape into the past.
Another obstacle Marty faces is when he meets his father and Biff, the villain, who taunts his father. Marty could let his father wander off but instead, Marty chases after him to help him. After Marty fouls up his parents meeting, Marty’s goal is to help his father gain confidence to ask his mother out on a date. Every problem Marty faces forces him to deal with is character flaw, which is the lack of confidence.
In any story, identify the hero’s change and the character flaw that’s keeping the hero stuck in a dead end life. In “Titanic,” it’s Rose not knowing she can change her life. In “Back to the Future,” it’s Marty not having the confidence to change his life.
Essentially, every hero must change so every hero must constantly be forced to change. Each hero has different character flaws but whatever it might be, that character flaw must be constantly faced until it’s finally overcome in the end.
In “Thelma and Louise,” the major character flaws of both women is that they allow themselves to be dominated by men. Every obstacle they face forces them to confront this flaw until they eventually change and learn not to be dominated by men.
So identify the change in your hero from his or her dead end life to their better life in the end. Then identify their character flaw. Once you know their character flaw, you’ll know exactly the types of obstacles to throw in the hero’s path that forces the hero to constantly face their character flaw.
Constantly facing and overcoming a character flaw is the only type of obstacle every hero really needs to face in any story.