Irish actor Liam Neeson knows his boundaries.

He said he would never play a younger man in a movie because he knows his audience would not belive it.

Neeson, who recently played the part of a Greek god in "Clash of the Titans", is ready to play more fatherly parts.

“I guess age has something to do with it," he said.

"I'm not about to play the quarterback on the high school team. I'm not someone who feels the need to play younger than my years.

“I'm drawn to a part because I believe I can do something with it, and part of that is recognising your strengths and weaknesses as an actor, but it's also recognising what people see, and what they will believe.”

Although he won't take on a younger role in the future, he did say he felt like a "school child" while filming "Clash of the Titans" with co-stars Sam Worthington and Ralph Fiennes.

“I certainly tapped into that childhood sense of memory," he told Irish film website movies.ie.

"You know, playing soldiers, having adventures, shoot-outs, car chases, all that. I think that's a big part of acting really - just tapping into that childhood imagination, that ease children have in believing they're someone else.

“That this parked car they're sitting in is really a tank, or the garden shed is really a prison, or a bank, or whatever. So, on that level, yeah, I got excited. I think it'd be a shame if I ever walked on a set and wasn't excited."