No plot would be complete without stumbling blocks. If stories didn’t have ‘oh’ moments they’d be a lot shorter and less satisfying. Readers like to see the characters struggle through challenges because it amplifies the achievement of winning, though it can be tempting to make things easier for them. These stumbling blocks are either built into the main plot or come as a subplot collides with the main plot.
An example of the stumble being built into the main plot would be when a character is presented with a task but doesn’t feel they can rise to the challenge and run away. This tends to be a common theme in the stories that require saving the world or epic destinies but, while some will tell you the character has to retreat, it doesn’t have to happen. Why is this? Because there are characters that would jump at the chance, it doesn’t mean they’re jumping at the chance because they want to save the world, they could have an ulterior motive. In The Lord of the Rings at first Frodo is reluctant to carry the ring and tries to get Gandalf to take it, but by the time they reach Rivendell he chooses to take up the task as ring bearer. Is this entirely to save the world? We can’t say for certain because one of the side-effects of carrying the ring is that it takes hold of a person and won’t let them go. So it could be good intentions but it could also be The Ring’s influence.
A stumble brought on by a subplot might be something like two characters with opposing agendas, or even agendas that begin the same but change as the story progresses. Lord of the Rings has these too, such as in the first book, Fellowship of the Ring, where Boromir begins as a member of The Fellowship off to save the world but he falls under the influence of The Ring. By the end of the book he tries to take The Ring from Frodo, causing Frodo to flee The Fellowship so no-one else will be effected by The Ring. Boromir is redeemed by trying to save the other hobbits but dies in the process and his subplot is resolved. While the journey continues the meeting of these two plots fractures The Fellowship and forks the narrative in the following books.
Without the collision of these two plots LOTR would be a very different story because Boromir wouldn’t die and The Fellowship wouldn’t separate. In fact, a large amount of the story that follows wouldn’t happen at all without Boromir’s subplot, which may have appeared insignificant to begin with. So not only do we have a subplot creating difficulties for the characters but also affecting a huge portion of the narrative. Although they are referred to as subplots these secondary plots are no less important than any other element of the story. ‘Sub’ does not mean less.
Obviously subplots don’t have to have such huge ramifications they can be small things that only cause minor inconvenience, such as having to alter the plan for a heist or approaching a personal problem from a different angle. But considering the huge ramifications a subplot can have on story helps us to remember that each one is important in its own right and its own little story. Considering the huge impact such a collision might have on the narrative also reminds us that we need to find those stumbling blocks for our characters and test their mettle. Making things too easy for the characters makes the story too easy which can have the same effect as making it too complicated and we want our readers to keep reading.
It might sound like a difficult balance to strike but this is why we need to experiment during drafting and editing to find those moments that challenge our characters and make our stories better.