What are your childhood memories of TV? I remember running home to watch The Simpsons. I’ve been on The Simpsons now. That was a real moment for me. And I loved Live & Kicking. The first time I’d ever been near a camera or a studio was when I was in the audience for that. I’ve met Jamie Theakston since and he always reminds me my on-screen debut was with him.
What’s your TV guilty pleasure? The show I miss when I’m away, weirdly, is Come Dine with Me. I watch a lot of it. It’s all down to the voiceover guy, Dave Lamb. Other versions in different countries just aren’t as good.
You’ve chosen some quite adult roles in the past – Equus, Kill Your Darlings and Woman in Black. Is it a deliberate attempt to shake off Harry Potter? I choose scripts by asking: what is the experience that is going to make me most happy? I’m very lucky, but there’s no grand career plan. Outside of Harry Potter or The Hunger Games, those kind of films that have a built-in fan base, it’s impossible to know if a film is going to be successful. So you just have to pick those you feel passionate about.
You’re back on TV in The Gamechangers. What’s it about? It’s the story of the computer game Grand Theft Auto, which was a huge part of my life growing up. I play Sam Houser, one of the guys who invented it. But I never had any idea about the detail of the trouble the guys got into, or even that it was such a British story.
Did you meet Houser as part of your research? No, this isn’t something that’s been done with their authorisation. We had to do it without them. I’d love to have talked to him. It probably does give you more subjectivity not to talk to someone you’re about to play, though. He’s made himself amazingly hard to research; there’s little about him online – really impressive considering how massive those games are.
Were you a big gamer as a child? Yes, although I was never very good at games. I still play Call of Duty and Grand Theft Auto. I got back into it when I was preparing for this role; it was a good excuse.
Is there a role out there you wish you could play? I don’t think so. I’m quite pleased with the roles I’m offered. Once you become known for picking interesting roles, you get an everwider choice. I’ve just finished a film called Swiss Army Man, and it’s 100 per cent the weirdest thing I’ve ever done. And I wouldn’t have been sent that script if I didn’t have this reputation for doing weird stuff. The flipside is you also get sent really bad stuff.
The funniest person on TV? There’s a very funny guy called Stephen Colbert in America, and I like Louis CK. In Britain, I’m a rabid fan of David Mitchell.
What makes you turn off? American Wheel of Fortune annoys me. The answers are so random, and I can’t understand how the contestants are getting it right. We do the best quiz shows in the world in Britain.
If I made you do a reality show, which would you do? I guess Strictly, because at least my mum and dad would be proud. But it’s not an option!
The Gamechangers is on BBC1 tonight (Tuesday 15th September) at 9.00pm