I've been editing the StarShipSofa podcast for three months and it has proved to be the education in storytelling I had hoped it would be. Seeing stories from the other side of the author-editor divide has given me a clearer idea of what a story needs in order to make it impossible for an editor to reject it.
The backwards construction of the previous sentence is intentional. I begin reading each story with the assumption it will be rejected. That's the fate of more than 95 percent of subs.
So, when I begin reading, I look for the following required ingredients. If any of the following are missing, the story's chances are slim. If they are all there, you just might force me to hold off on pressing the Reject button.
(Caveat: these are guidelines. Any one of these rules can be broken. Heck, theoretically they all could. But if you do that, your story better have something really, really incredible that compensates. Maybe shockingly beautiful writing. Maybe a concept or a voice that makes me stop caring about the items on the list. My only warning is, if you think you're the exception, you're probably not.)
So, to my requirements list. Your story must have:
A first paragraph with crystal clear sentences. You cannot begin with muddled meaning. Edit out all ambiguity except for what you put in deliberately and for good reason. If I stop after one of the early sentences to ask Whaaa?, your story is pretty much doomed right there. That may seem impatient and unfair, but I have to be impatient because the audience is. Now, if it's only one sentence, and not part of a pattern, then a strong finish may prompt me to ask for a rewrite. Or, if I sense your vagueness is a deliberate set up, that's something else entirely.
A protagonist that appears on the first page. Show me your protagonist and given me some defining fact about them. You should put in my head the beginnings of a sharp, clear portrait of this person. I need to feel I know him or her.
A protagonist, that is, with a goal. I'm reminded of a published story where the protagonist had no goal. He was trapped in a hopeless situation and knew it was hopeless. He talked for a while with a similarly doomed person. Then the End came and they both faced it in their respective ways. That story got published, but it would never get published by me. Now, your protagonist's goal may change over the course of the story. In fact, a change of goal can give the story a beautiful beginning, middle, and end. Which brings me to...
A beginning, middle, and end. Since this is not a novel, some shorthand can be used. In the case of the famous six-word story, "For sale: baby shoes. Never worn." the entire first and second acts are implied. But they are vividly implied, and there's no question they are there. Your story, too, needs a beginning and middle. It also needs...
A strong ending. This is the complaint I hear from other editors: a story has a compelling protagonist, its premise is original and entertaining, some good things happen, and then the prose just stops. The author never had a plan. That's not going to work. You know what else won't work? A lack of...
Original ideas. I read a story that flowed effortlessly, and was a joy to read. Unfortunately, it was a thinly disguised retelling of one of the biggest blockbuster movies from the last 20 years. Thank you, O Author, for making the Reject button such an easy choice. Finally...
A strong villain. I think this is the rule with the loosest interpretation. Your villain can be time, circumstance, or a power that goes unnamed and undefined. But your protagonist needs something to contend with.
Put all those things in a story, and nothing extraneous, and you will definitely have me moving your story, with great surprise, to the Further Consideration pile.