The most remarkable thing about Cynthia Nixon isn't that she's starring on Broadway alongside William Hurt, Sigourney Weaver, Harvey Keitel and Judith Ivey in director Mike Nichols' hit, Hurlyburly. No, the most remarkable thing about Nixon is that, at 18, she can compare the feel of Hurlyburly to her experience in three other successful New York plays: Lydie Breeze, The Philadelphia Story and Nichols' other current hit, The Real Thing, which she left after two months to take on her present role. "I like taking on a new play," says Nixon. "I get bored fairly easily and this was a better part. But even though I've been in Hurlyburly since February, the show still feels exciting."

Nixon credits her precocious success to hard work and good bone structure. The only daughter of a publicist mother and a financial researcher father, who are now separated, she began auditioning at 11, when a family friend suggested she give showbiz a try. "I was a marketable type," says Cynthia, who began landing theatrical and film roles on looks alone. "I had blond hair, fine cheekbones and no New York accent." She gradually sharpened her acting skills, and by the time she made her big-time debut opposite Blythe Danner in The Philadelphia Story in 1981, she "had kind of figured out what I should be doing," an assessment she backed up by winning a Theater World Award for that role.

Nixon says she finds Hurlyburly, a drama about L.A. lowlife in which she plays a naive hitchhiker, wonderful but depressing. To foster the play's spirit of misogyny and exploitation, Nichols put men and women into separate groups during rehearsals and advised Nixon, who was trying to pick up a Midwestern twang, to watch a cable talk show that emanated from that region. "It was a strange show," says Cynthia. "They had on all these porn stars and prostitutes, and I'd listen to their accents. I sounded too educated, too middle class."

Away from the stage Nixon is a Barnard College freshman, an avid New Yorker and a self-proclaimed strange eater who loves carrots in barbecue sauce. She has a boyfriend but says her best pal is her mother, and she is self-contained enough to shrug off a nightly onstage kiss with matinee idol Hurt as "the sort of thing that used to embarrass me, but doesn't mean much now." Her greatest ambition is to play the role that most suits her ethereal blond looks—Alice in Wonderland—but other than that she says she'll judge her career opportunities as they arise. "Acting is fun and it's exciting; it takes time and effort, so I'm not bored," says Nixon. "The whole thing has really been a miraculous stroke of good luck."