Jim Sturgess (“The Other Boleyn Girl,” “Across the Universe”) stars in “21,” the new movie based on the real-life story of a group of MIT math whizes who won millions of dollars in Las Vegas. The character he plays was inspired by Jeff Ma. I spoke to them both about the movie.

Jim Sturgess

Your American accent in the film is excellent! Was it difficult to learn?

JS: I did not have very much time to prepare for the dialect, two weeks or so, so it was fairly intense. A decision was made not to give him a thick Boston Southie accent so there would be no extremities about who he is as a person. We did not want to be so specific it would be distracting or people would think that’s the points off him.

Your director, Robert Luketic, is well known for “Legally Blonde” and other bright, light-hearted comedies with female leads. Was this a big adjustment for him?

JM: I’m so proud of Robert for this film. He wanted to break away from the genre or the mold he was known for. I hadn’t really seen any of his films and I was nervous, all these romantic comedies, but “Legally Blonde” was an intelligent look at the genre. Once I met him I was completely at ease. He wanted it to be about real people. He didn’t want it to be “Revenge of the Nerds 2.” Put in another person’s hands it could have been completely that way. They were just students. We didn’t look at them as nerds.

Tell me about the character you play. What is it like to play someone who is such a super-brain?

JS: There’s just a confidence and a quickness about what you are thinking. He’s fairly mild in his approach to life but when he talks about anything mathematical that’s his world and where he feels comfortable. And then you put him next to a girl and he’s hopeless!

Had you ever played Blackjack before this movie?

JS: I never had played blackjack. We played it and played it. That is all there really is to do in Vegas, and we were indulging with that as much as possible. We had blackjack camp and that taught us basic strategy. I don’t think it is possible to be a good or bad player unless you are beating the system like these guys did . It’s a game of luck.

What do the scenes with your character’s mother add to the story?

JM: Ben and his mother brought a conscience to the film. It showed he had somebody to let down who would be disgusted by his behavior. My mother is the same. Your mother’s always slightly in the back of your mind.

What was it like to shoot in Las Vegas?

JS: Vegas just kind of blew my mind. We had a great time there but we were there too long, a month and a half. It’s designed for people to come in and spend all their money and have a crazy time and go home to their normal lives. When it becomes your life it is too much and by the end of it we were desperate to get out. Boston was the antidote. It is very similar to England, great when you need a normal pint in a normal pub.

What were the challenges in adapting the real-life story for a movie?

JM: Film has to be its own thing. There are rules of movie making. It’s roughly two hours and the audience has to be engaged. While it was not the case in real life, for the movie, Ben had to have a purpose to earn the money . If he was gambling for an idle purpose, just for the money, if he did not have some lesson to learn, it would not work as a movie.

Earlier this week, I saw you in “The Other Boleyn Girl,” a historical drama. What makes you decide that a project is right for you?

JS: It is different each time, different reasons depending on where you’re at in your own life space. For this one it’s like it’s going to be fun and inspired by true events, it reads like an absolute piece of fiction and captures your attention. Your ears really prick up and then I was completely hooked.

What makes you laugh?

JS: Anything tragic is normally pretty funny. The last comedy I saw was “Superbad,” which I thought I wasn’t going to enjoy but there was so much heart to it and so much honesty and it was ridiculous as well. If people are trying to be funny you just sniff it out but if people are going to be honest, it is really funny. “The Cable Guy” is the most warped and tragic film so lonely, but very funny, hilarious.

And what inspires you?

JS: Absolutely everything! Things I’m completely unaware of. Having your ears and eyes as open as you possibly can.