How did 12 Rounds fall into your hands?
"It was something the producer sent my way and I liked the idea of going back to my roots and doing an old-fashioned action movie that is not visual effects and flashy stuff like that, almost like a throwback to late '80s, early '90s action movies."
It's like those films where an everyman is thrown into an extraordinary situation. How did you give 12 Rounds a modern twist?
"I really like those movies where an ordinary guy is put in an extraordinary situation and has to rise to the occasion. We are so used to seeing comic book and superhero movies with giant effects. I grew up watching the action movies of the '70s and I just wanted to give it a modern shooting style but still have that feeling where the stunts are done for real and it's not CG-created."
Did you speed up the filmmaking process so the actors could bring more urgency to their performances?
"Definitely. I really wanted to make it guerrilla-style where we had three cameras and we wouldn't even rehearse it. I put the cameras on dolly tracks or handheld, in three different directions, and told the camera operators, 'Do the best you can.' That way it was fast and it was fresh. The actors never had to hit their marks perfectly, I just said, 'Let's shoot this like a documentary, do whatever you want to do and the cameras will do their best to capture it.'"
Were you familiar with John Cena and the WWE phenomenon before you came on board?
"I was familiar with WWE, I wasn't an expert on it. To be honest, my very first reaction was 'can this guy act'? What kind of a guy is he? I was a little bit apprehensive at first. When I met with John I just saw what a great guy he is. He's very, very smart, he's very funny. He is just an all-around great performer and a very humble guy. He was eager to give the movie all he's got. I just felt that he had such natural charisma [and] I was completely won over by him."
Because he's such a physically big actor, did you have to tell him to stay away from the gym to keep the character believable?
"My whole thing was to try to dress him down. We agreed from the get-go that he'll never be shirtless and he'll wear long-sleeve shirts so you don't see so much of his physicality and he would feel as much like a normal guy as possible. I was trying to keep him away from the gym, I think he secretly went anyway. The goal for all of us was to keep it away from the WWE persona and make him a real guy."
What was the most difficult action sequence to film?
"The most challenging was the street car scene because we were in the very centre of New Orleans. We had to shut down several intersections and deal with the traffic and the tourists and have a street car travelling at pretty high speeds involving crashes and stunts on top of it. It was still connected to the electricity. You touch that and you're dead immediately."
Was John able to do all of the stunts?
"John did pretty much everything. You can see in the movie he does all the driving himself. The toughest one for him was to slide down the rope from the burning bank building. I discovered on the day that he had a fear of heights. I guess he hoped we'd be doing some greenscreen or something. That was hard for him but he was game for everything."
Aidan Gillen carries on the tradition of having Europeans as villains in Hollywood films. What makes us Europeans so menacing?
"I looked long and hard for the villain and I felt finding someone who would be physically imposing next to John would be almost impossible. It should be someone who feels super-intelligent and who can always be a step ahead of him mentally. I met a lot of actors and Aidan just exudes such intelligence and strength as a person - he was perfect. I guess it's shorthand in cinema language that you pick a European person for the villain and some kind of intelligence comes as a by-product automatically."
12 Rounds is out in cinemas this Friday.