So I was doing this thing. I'm not sure whether to call it a talk, a workshop or just a coffee out with a lot of very fine people, but I thought it was going really well. I was having a ball. And then I was asked a stumper: could I recommend any books on how to structure a theatre play.

Not one single clue in my head.

Blank.

Um.

It's easy to go off thinking we all mean the same thing by the word structure and, well, not, so let me say what it is to me. It's the shape of the story. And the sequence. It's more than just having a beginning, a middle and an end. It's more that “man walks into a bar – ow” is a joke but “Ow – a man has walked into a bar” is not.

The trouble is that structure just happens while I write. It's not what I struggle with. So I turned to Facebook and asked all the writers in the house what books they recommend.

The short answer is this:

Anna Lawrence Pietroni says: “How Plays Work” by David Edgar*

Laurence Inman says: “The Crafty Art of Playmaking” by Alan Aykbourne

And Lindsay Stanberry-Flynn just lobbed in “The Screenwriter’s Roadmap by Neil Landau

*Incidentally, I am slightly embarrassed by the first of those: I know David and I've read his book. I should've tripped that off the tongue last night, complete with Amazon link.

But the longer answer is that poet Nina Lewis said come on then, show us what you do if you think you're hard enough. (She said it far more nicely, but.) I'm going to try. I don't know how this is going to work so there might be some irony for us in finding that actually I couldn't automatically structure this. But I also promise that you're still welcome to a biscuit if you choose instead to go read David Edgar.

It won't be a chocolate biscuit, I'll tell you that.

It also won't be a long explanation. Because for me structure comes from character. You're trying to look deeply into these characters and that tends to be done at a really key point in their life. A definition of a film used to be that it was about the biggest single point or event for the main character. Television used to be more pragmatic and have an eye toward bringing them back for another episode next week. These days those have blurred as films spawn sequels and television is braver about smashing its characters.

But it's always an important moment in their lives and whether that's something that comes from within themselves as they grow or, more usually, it's an external event or another person affecting them, that's a structure to me. You see them before this moment so that we understand who they are, then we see the moment, then we see how changed they are. We see whether or not they survive.

I am trying to get deeper into my characters. I don't care about plot so much: I suppose I do and I've been told I've got a plotting kind of brain. But if you don't make me believe your characters, I won't care for them and it doesn't matter to me how fantastic or how brilliantly structured your plot is, I'm gone.

The deeper you get, the more interesting a character is and there comes a point where they stop being a list of attributes and characteristics and instead become people. When that happens, when they become people and you are believing them, the things that affect these characters can be physically small yet have shrapnel impact. You don't need the important moment to be all that important, it doesn't have to be Mission: Impossible, it can be very quiet and small. I think I lean toward the bigger moments because characters reveal so much of themselves in peril and under pressure but I also do it because I'm a coward. It's definitely easier to write big events than small moments but it's those feathers that engross me.

I do also have a stand-by habit for deciding what happens next to a character and it does work, it does automatically give me a structure, but it does tend toward the bigger kind of event. But it's just this: find out what the single most important thing is to that character and then stab them in the back with it. The surgeon obsessed with protecting her hands gets them caught in a car door. (I just winced. Did you? Sorry.) Someone who drives for a living and could tell you the [INSERT SOMETHING REALLY MINUTE AND TECHNICAL] about cars loses his sight.

Both of these are incidents or events and so are plot but to me they are destroying what has come before and requiring me – and most importantly my characters – to go somewhere new. Somewhere uncomfortable, for preference.

And that's structure. The End.

Except.

Two more things. One possibly annoying, one perhaps more useful.

The annoying one is that maybe I do have a plotty kind of brain because regularly, routinely, I will be writing the end of a story and I'll need something, I'll need for something to have been set up way back at the start of the script – and it was. Something I wrote without consciously planting a seed for later, has grown into a tree for me by the end. I actually think it's that I just use everything, that there is never a spare burr or a genuinely offhand remark from a character, that I cannot help but tie off everything in some way. And actually I think you can argue that's a failing in me. I don't construct and I don't plot but it becomes too constructed and too plotted. Nonetheless, when I'm there at the end and I realise I've already given myself all the material I need, it feels fantastic. Feels less like I'm conjuring this stuff, more that I'm just watching and listening to my characters and what they're doing.

The more useful thing. Cheat.

When I do Doctor Who audios, they two hours of drama and you'd think that stretches out in front of you both excitingly and slightly terrifyingly. But those two hours are always done in four episodes, keepng to the classic Doctor Who format. Episode 1 obviously has to draw you in and set up the story. Episode 2 makes things much worse for the characters. Episode 3 sees the baddies have the best of times: they're winning in episode 3. And episode 4 obviously has to solve the day.

More, episodes 1 through 3 have to end on a cliffhanger. Each typically has to be bigger than the one before, but they must be there and that means you have to find three big moments. You find them, you have to place them at particular points, you have to build up to them and then in the next episode you have to resolve them.

You can hear how it works for me on any of my Doctor Who dramas including the next one, Doctor Who: Scavenger. That's a Colin Baker and Lisa Greenwood tale which is out in March. But you know already that it will have a structure and a shape because it just does.

I was on BBC Radio WM this week, answering listeners' questions about writing. The Adrian Goldberg Show was featuring my book about productivity for creative writers, The Blank Screen. Lots of the callers were writing novels, many had finished non-fiction books, I got to speak about how you go on to get published. But there was one fella who was particularly interested in scriptwriting, as I am, and just as he was hanging up at the end, he said something I only barely managed to get any response to.

He said this: “of course I wouldn't give [TV companies] all my ideas and the scriptwriter would have to write them up then.”

And what I managed to say before he was gone and the next caller was on, was this: “Ideas are ten a penny, it's what you do with them that counts and so you have to write it all.”

I worry that he will have taken away from this that I meant you have to write all your ideas.

I did.

Whether it's a script or a novel, don't ever think you'll hold this or that idea back to the next episode or the next book. Do it now. Maybe it won't fit, maybe it'll turn out to be a rubbish idea and you'll chuck it away, but use everything you've got because scriptwriting takes everything you've got. And anyway, if it's then tougher to find ideas for the next piece, you'll just have to work harder on the search and you'll get better material for doing so.

But actually, that wasn't what was on my mind when I garbled that. It also took me an hour to twig that he thinks scriptwriters just write up people's great ideas, that this part is the trivial bit after you've had this great creative thought. So like a typical writer, having said something he may have misunderstood and having taken an hour to notice what he really meant, I've been thinking what I could've told him, what smart line I could've thrown back. And here I am, writing down the smart line.

It doesn't seem that smart now I come to tell you. It seems a bit fatuously obvious, really. If you want to write, why wouldn't you want to write? Because we think writing is easy right up until the point when we try to do it and then we start thinking how nice it would be if someone else would do the writing bit.

Look, I'm a writer, of course I'm going to say that writing is hard. But look at the panic in my face when I say it: I'm not trying to sound great, I'm asking you why I do this stupid thing and why did I ever think I could? Like any other writer in the world, I'm also asking you whether I can – as in, am I really allowed to do this, don't I have to get a proper job? – and I'm asking you whether I can – as in, am I capable of writing? I don't know, I never know, I don't think I can know. (I also said this on BBC WM: “Look at me, I'm rubbish but I keep going.” Nobody seemed to disagree. Bastards.)

If you start writing because you think it's easy, fine. You'll find out. If you go into writing because it will make you millions, fine. Also, good luck with that.

I'm all for the end result. I think you have to get published, you have to be produced, I think that is as much a part of writing as anything else. But the reason I'm a writer is for the writing. The shovel work of doing this.

There are harder jobs.

But there are also easier ones.

I just don't think there are better ones.