Dermot Mulroney, at 27, Knows a Lot About Playing 18-Year-Olds

For 27-year-old Dermot Mulroney, the worst thing about film acting is the E-word: Eighteen .

Six years after earning his college degree, Mulroney is still using the E-word in his dark new drama “Bright Angel,” and playing an E-type in the upcoming high-school drama “There Goes My Baby.”

Back when he was actually 18, Mulroney was entering Northwestern to study communications. He acted occasionally in college productions but was more interested in learning behind-the-camera skills.

“I pursued acting, but in a back-burner sort of way. I thought an acting career would be a delight, but I never imagined it would be possible.”

A month before graduation, he saw a sheet on the bulletin board soliciting sign-ups to audition for an agent from William Morris. “I had been planning to carry spears on stage in Chicago while waiting tables to pay the bills. But I did the audition and got signed up and moved out.”

Mulroney slid quickly into the Hollywood mainstream, playing a teen father in the 1987 ABC movie “Daddy,” an AIDS patient in “Longtime Companion,” an outlaw called Dirty Steve in “Young Guns” and a bumbling intruder in “Career Opportunities.”

Although most of Mulroney’s parts have demanded a rugged, outdoors look, the Virginia native is, surprisingly, an excellent cellist. He put that skill to use in the romantic comedy he’s just completed, “Samantha.”

In the noir-ish “Bright Angel,” he plays an inarticulate kid who goes on the road with Lili Taylor and tangles with Burt Young. “I don’t think I’ve worn a suit in a movie yet,” the broodingly handsome Mulroney says. “Someday maybe I’ll do those going-to-the-office type parts.”