Whenever I write a story – any story, short or otherwise – the first thing I have to do is make a world for the characters to live in. It’s perhaps the easiest part of the process, but still one which needs some thinking over before you put pen to paper (or fingers to keyboard).

For a start, it’s important to think logically and sensibly about the world your character is going to find themselves in, and to adapt either your characters or your world to suit your story. If your character is in a wheelchair for example, you’re going to need some way of getting them upstairs without breaking up the story, or else confine them to one floor.

Let’s take a solid example: The haunted house. And by that, I also mean the haunted town (See Stephen King’s IT for example) or even the haunted spaceship (which is essentially the plot of Alien).

Let’s walk through those examples and see what we can do with the worlds they need.

So your character – let’s call him Joe – has found themselves in your haunted house. You want Joe to stay there, at least until the story is finished…or until Joe is…

First question about this world: Why doesn’t Joe simply leave?

I know if I was in a haunted house, logically, sensibly, I’d head for a door. But I need some walls for the story…can’t have Joe wandering off without finishing what I’ve got him here for!

The door is locked? Fine. What about a window? Bars across them?

Hmm…okay. Now I’ve got Joe looking round the little haunted house I’ve just made and interacting with it.

Can he smash the glass and shout through the window for help? No, the house is on an island. Now I’m expanding the house to the local area around it.

Can he use his cell phone to call for help? Flat battery. No signal.

The point is, whatever Joe chooses to do at this point, the little world I’ve made won’t let him until he finishes the story. Joe is going to get increasingly desperate to get out, and at some point in his wandering through the haunted house, he’s going to meet the bogeyman and one of them won’t make it out alive.

In Stephen King’s IT, he has the main characters trapped by the fact that they’re children, and only children can see the Big Bad. Where else could they go? They can’t leave exactly leave town at the age of twelve. In Alien, the crew of the spaceship are trapped inside a literal vacuum of space while the monster stalks them.

And walls don’t always have to be physical. Joe could hear his little sister screaming upstairs, and there’s no way he’s going to walk away from that. Even if he gets out of the house, he’s going to go right back in there and rescue her like a good brother.

This is a simple example, but you can hopefully see how the world has adapted as I’ve needed it to. A character who can easily walk out of a story isn’t going to make an interesting read.

So when you create a story, think about how the world you create will shape that story, and think – logically and sensibly, no matter what the genre – how you can keep your characters there until the end. Keep bouncing them against the walls you’ve made for them until they break through.