HENRY SHIELDS WASN’T always going to get into theatre. 

He studied nursing in university but dropped out after the first year.

Then the stage came calling... and soon the 31-year-old playwright and actor had co-created The Play That Goes Wrong, one of the biggest West End comedy hits in years. 

Yet for Shields and Mischief Theatre, the fun was only getting started... 

Tell us about your new play... 

It's called Groan Ups – it's about growing up. All of us play the same characters at three different points in their lives: at six years old, at 13 years old, and at 30 years old. It's a lot of fun to rehearse!

How did you get into theatre?

I didn't really know what I wanted to do with myself; I studied nursing at university, and dropped out after the first year. Auditioned for drama school and got into LAMDA. I met the other guys there, and we created Mischief Theatre.

The Play That Goes Wrong was your debut production...

That was originally based on Michael Green's The Art of Coarse Acting plays – little mini-versions of The Play That Goes Wrong. It started out as an hour, and then grew to two hours over a few years.

Does stuff ever go right during a show?

That's the problem with that show: things do go wrong, but when things go wrong, nothing happens. It's all carefully set up to have things exploding, collapsing, bursting, whatever, and if there's a failed pyro or someone forgets a line, all it means is nothing happens!

At least the audience mightn't realise...

Exactly. They'll just think, oh, that was a boring scene.

Rehearsal must have been intense.

The first time we rehearsed we only had two weeks, no director. It was in this tiny little room in London Bridge. The show only ran for 45-minutes: to make it a full hour, we ended with this 15-minute, in-character Q & A with the audience.

Moving to bigger theatres must have brought more opportunity, but also more challenges?

Yes. We had to scale things up significantly. In order to take the show on tour, we needed a runtime of two hours. A lot of stuff was added, big set-piece stuff. I got hit by a piece of falling set in our first show in Canterbury: it got a big laugh.

What's your writing process?

There are three of us, who so far have written everything that Mischief Theatre has done. We literally sit in a room with a laptop and try and make each other laugh. The funny stuff gets written down, and the stuff that isn't funny gets ignored. Beyond that, there's a level of technicality to it, where you have to start talking about structure and characters, story, how things interweave. I think that's just experience and slogging away at it, really. You spend hours and hours talking about tiny different plot points; it becomes quite a technical exercise.

There are so many payoffs in your scripts...

For one gag, we had to draw everything to ensure each object ended up in exactly the right place. Some of the payoffs you plan and you put in. Once we've written a script, we go back to the beginning, read through it, and note down anything that we think could be a callback. Then we go back and try and find a way to weave it in.

How do you know when a joke is going to land?

You have to have a bit of a leap of faith, occasionally. We do a lot of tests. When we've written a new script, we take it to the cast, do a read through, and do rewrites and rewrites for a couple of months. Then we do a try-out with a practice audience. We'll probably get it 60-70% right, then there'll be 30% of bad material that needs to go. You keep cutting away until you get as close to 100% as possible.

There's a lot of killing your darlings. It's painful sometimes, but you have to develop a very thick skin in terms of letting stuff go.

Are there many jokes that you're really proud of, but then don't land?

Yeah, loads! In Comedy About A Bank Robbery there was a whole section that we really thought was going to work. [It involved seagull puppets.] We tried it out with an audience and it died a horrid death! It lasted one show; it was such a failure we had to remove it.

First night nerves or excitement?

Both! In equal measure. The first night is always terrifying – we come off sweating buckets, heart racing the whole way through. Usually I calm down pretty quickly. After one night I'm OK. And as nerve wracking as it is, the opening night is always the most fun. There's nothing like hearing a joke get a laugh for the first time. In the opening night of Play That Goes Wrong, we were listening to the audience backstage, going, 'oh, they're laughing! God, we're getting laughs! This is amazing!' We had no idea if anyone would even like it.

Surely you must have some idea it was funny?

Well, now we're in a place where we go in with more confidence. Doing Groan Ups, I feel I know that a lot of it is very funny. I feel very confident about the stuff we've covered in rehearsals – but you never know for certain. And as well as knowing a lot of it's going to be funny, I know some of it's not going to be funny – and I don't know which bits aren't funny yet. I know they're in there, and currently I think they're funny, and I'm wrong. There's no way of telling.

Well there is...

Do it! Do it in front of an audience, and have that horrible moment!

Is it a weird sensation watching a new actor take over your role – especially a role you wrote?

Yeah, it's very, very weird. I've seen so many actors who are exactly like me, but slightly different; some of them slightly better than me. The guy playing my part in the American production – he's me, but slightly better looking, and I hate it! It's like when you go to audition for something: you sit in the waiting room outside, and you can see all the people waiting around looking identical to you. I'll be surrounded by tiny, different versions of me.

It sounds like some kind of multiverse, alternate reality trip...

There's me if I wore a leather jacket. Wow.

Do you agree that comedy is harder than tragedy?

Definitely. You never know with tragedy, that's the thing: you can see a beautiful tragic play and the audience won't even know whether or not the rest of the audience has been affected by it. There's no feedback. Whereas comedy, you're either getting laughs or you're not. If you make a mistake, every knows it immediately: a joke doesn't get a laugh, the entire theatre knows it. And it's tough.

How does the Goes Wrong format translate to TV?

I hope it works! We've done something that we think works. We've tried to create a theatrical vibe in the studio: so we have a live studio audience, we start each show with a direct address to the audience, you see the set behind, so it feels very much that we're in the live-action world. I think that helps to bridge the gap between TV and theatre.

Favourite part of the job?

The creative freedom. We have so much influence in everything we do. Like with the TV show, it was really great to be working in TV but have creative say over everything.

What are your plans for the future?

We're working on Magic Goes Wrong, with Penn and Teller; I think that will be our last Goes Wrong stage show for a very long time, maybe forever. Personally, I'm looking to do more TV and film. I'm trying to do more stuff outside of Mischief, much as I love working them; I've reached the point where I want to try different stuff. There's a film and TV show that I'm writing at the moment.

Henry Shields

Groan Ups is playing at the Vaudeville Theatre