The best thing to be in Hollywood these days is one of the boys. In 1983 the new kids in town staged an unexpected coup that threatened the longstanding Redford/Beatty/Reynolds regime. It was a good year for such charter members of the brat pack as Sean Penn and Tom Cruise, but none in that crowd can claim the double whammy of mild-mannered New Yorker Matthew Broderick, just 21. His performance as America's cutest computer nerd made the summer smash WarGames eminently palatable (if not quite plausible). And playing Neil Simon's teenage alter ego in the stage comedy Brighton Beach Memoirs—his Broadway debut—brought him a Tony award. With only a few credits Broderick has already fashioned a distinctive persona: His characters are shotgun marriages of street smarts and innocence, mischief and morality.

Like his colleagues, Matthew is fulfilling his teenage fantasies while barely out of his teens. For his upcoming film role as an impish thief in the medieval adventure Ladyhawke, he was paid a reported $750,000 and chauffeured around Italy for four months. But success spoilage hasn't set in. "I'm not gonna go crazy and buy five Rolls-Royces," says Matthew. He still lives in his mom's Greenwich Village apartment and dates UCLA coed Valerie O'Brien, who was an extra on War-Games. He's the son of late actor James (Family) Broderick, who died of cancer the day after Matthew began rehearsing for Brighton Beach. That loss colors the young actor's perspective. Of his newly acquired fortune, he says, "The nice thing about the money is knowing that if anybody in my family gets sick, I can take care of them."

Finished with Ladyhawke, Broderick returns next month to Brighton Beach. For him the stage has been the thing ever since he appeared in a high school production of A Midsummer Night's Dream. "It was the first thing I felt sort of confident at," he recalls. "I felt—I don't know—I impressed myself." Whether in a school play or Hollywood movie, Matthew has the same concern. "I don't want to embarrass myself in front of people," he says. "I worry about that endlessly." Judging from his work, worrying is just one of the things Broderick does well.