In setting out to write a short story, it doesn't hurt to know that the short story is a fairly young form, dating back only to Nathaniel Hawthorne and his 1837 book Twice-told Tales. For Edgar Allan Poe, who called them "prose tales," the fact that short stories could be read in a single sitting was key to the form. It allowed the reader to have an uninterrupted experience of the fictional world.
As a recent genre, the short story has few formal elements that are not shared with the novel. The challenge for the short-story writer lies in developing the major elements of fiction — character, plot, theme, point of view, etc. — in about ten to twenty-five pages. (The cut-off for most journals is 10,000 words.) To meet this challenge, short-story writers generally follow, consciously or unconsciously, a pretty standard list of rules:
Use few characters and stick to one point of view.You simply will not have room for more than one or two round characters. Find economical ways to characterize your protagonist, and describe minor characters briefly.
Having only one or two protagonists naturally limits your opportunities to switch perspectives. Even if you're tempted to try it, you will have trouble fully realizing, in a balanced way, more than one point of view. (Click here for information on choosing a point of view.)
Limit the time frame when you write a short story.Though some short-story writers do jump around in time, your story has the biggest chance of success if you limit the time frame as much as possible. It's unrealistic to cover years of a character's life in twenty-five pages. (Even a month might be a challenge.) By limiting the time period, you allow more focus on the events that are included in the narrative.
Be selective.As with poetry, the short story requires discipline and editing. Every line should either build character or advance the action. If it doesn't do one of these two things, it has to go. William Faulkner was right to advise writers to kill their darlings. This advice is especially important for short-story writers.
Follow conventional story structure.The standard rules of narrative we all learned in our high school literature classes apply to writers as well. Though you may not have room to hit every element of traditional plot structure, know that a story is roughly composed of exposition, conflict, rising action, climax, and denouement. However much you experiment with form, something has to happen in the story (or at least the reader has to feel as though something has happened). Things like conflict and resolution achieve this effect. Storytelling may seem magical, but the building blocks are actually very concrete.
As with any type of writing, the beginning and the end are the most important parts. Make sure your first and last lines are the strongest in the story.
Know when to break the rules.As with all rules, these are made to be broken. Alexander Steele points out in his introduction to the Gotham Writers' Workshop's Fiction Gallery that the short story lends itself to experimentation precisely because it is short: structural experiments that couldn't be sustained for three hundred pages can work beautifully for fifteen. And today, the lines between genres such as the short story and the poem are blurred in exciting ways.
Keep in mind, however, that telling your story is still the most important thing. If breaking a rule allows you to tell your story more effectively, by all means, break it. Otherwise, think twice, or at least be honest with yourself if the innovation fails.