Starting a story is difficult. Continuing it seems far easier, far more logical. At the same time, this section of your story will pretty much determine what the rest of your story looks like. It’s important, almost more so than your beginning.
Stories, at the end of the day, follow a very basic structure.
Something happens. Someone reacts. There are consequences. Those consequences then prompt reactions from others. these reactions then have consequences. And now we’re in the middle of your story.
Reactions reveal something about the main character. They are important. But consequences – they promise multiple things: story length, atmosphere, character arch, thematic arch.
If the consequences of the first major decision of the characters are large, then the story will be long. If they are small (small in the number of people they involve/how difficult it is to resolve them, not small in the impact they have on the characters) then the story will be short.
A short story can essentially be “something happens, character reacts, consequence occurs”. If those consequences don’t prompt significant action in others, then the story is essentially over unless you make something else that is unconnected happen.
A series of “happenings” that are not connected makes an episodic story – there is no clear cause and effect.
Look at the television series. The start of each new episode in a new “happening.” Within the episode there are far smaller happenings which are tied to previous actions and decisions made by characters.
So your choice of consequences determines both the structure, and the length of your stories.
If the consequence of your main character killing the king is that no-one except the main character knows about it, then you have a short story until someone else discovers it. There are no large consequences, barring the internal ones. If those internal consequences drive the main character to do something which effects more people (so a larger consequence) then you again have a longer story.
If, however, the consequence of your main character killing the king is that everyone knows it was murder, and thus there’s a fight over the legitimacy of the heir – well. That’s a far larger story.
Consequences hint at the genre of the story (one of the above examples is a political drama, the other is about someone’s internal struggle with guilt). They also hint at thematic and character arch. The above stories are going to have a different pattern of character growth, different obstacles for a character to overcome. They’ll look at different issues over the course of their stories.
Much is said about character decisions. And character decisions are important – but they don’t determine how the story goes after those decisions. They just show what the character is prepared to do. They give clues to how the character will act in the future. They show us the characters morals.
It is the consequences of those decisions that are important when talking about structure and plot though. A character can make as many decisions as they want – but if they don’t effect the world around them, if there are no consequences to those decisions, than your story is going to be very short.
Image taken from Flickr, under creative commons, attributed to MattyFlicks