In The Judge, Iron Man star Robert Downey Jnr takes a more realistic role

To say that The Judge has an unusual pedigree would be an understatement. The serious drama's star and executive producer is Robert Downey Jnr, who is best known these days for his portrayal of quick-witted, motor-mouthed billionaire Tony Stark (aka Iron Man).

The film's director, David Dobkin, has directed broad comedies such as the Jackie Chan and Owen Wilson feature Shanghai Knights, while the man brought in to whip the original screenplay (written by Dobkin and Gran Torino scriptwriter Nick Schenk) into shape, Bill Dubuque, is an ex-headhunter who has sold scripts, but had never seen them become films before.

This motley crew of collaborators has yielded an intense and moving family drama about a high-flying Chicago lawyer, Hank Palmer (Downey), who returns to his small town home of Carlinville, Indiana, for his mother's funeral. Once there, he has to defend his father, Judge Joseph Palmer (the singularly great Robert Duvall) against a murder charge.

Downey concedes that handing over the reins of a stirring, complex offering like The Judge to a director best known for conceiving pratfalls and scatological jokes might seem like an odd decision. "Sure, he's the Wedding Crashers guy," acknowledges the actor, who's wearing a pair of purple shoes for this interview at a Santa Monica hotel in Los Angeles.

"But Dobkin, as anyone who knows him will agree, is a complex and capable person who just happened to start doing comedies," Downey says. "The reason we're sitting here is because something happened in his own life. And he did what we all do as artists and writers; he started fantasising about a story that was not dissimilar, a story that he could process his own life through. That's how he wound up developing this script."