THIRTEEN YEARS AGO, WHEN Reality Bites star Winona Ryder was not quite a decade old, 15-year-old beauty Brooke Shields popped up in a series of antismoking advertisements and posters. "Smoking spoils your looks," she warned in one ad, a cigarette in each of her ears. Winona doesn't seem to have let Shields's message sink in quite deep enough. Ryder, 22, one of the signal actresses of her generation, smokes like the tailpipe of James Dean's old Harley in Reality Bites, that comedy-drama documenting twentysomething love and angst She lights up in front of the television, in the car, in the office, in the middle of a kiss with costar Ethan Hawke (who also smokes, onscreen and off; Reality screenwriter Helen Childress says Ryder is a celluloid smoker only).

But here's the part that really troubles some people: Ryder never looks dumb in the movie. With the help of her cigarette, never is she less than pensively alluring. Hawke, to be honest, looks pretty cool too. So does Jason Priestley, chainsmoking when he's away from those Beverly Hills, 90210 cameras. (Luke Perry can take it or leave it.) And how about Christian Slater and Johnny Depp, or any of the other young, tobacco-stained Turks who—to the consternation of such antismoking advocates as Patrick Reynolds, 45, grandson of tobacco-industry giant R.J. Reynolds—are idolized and imitated by potentially millions of teenagers? Couldn't Winona have considered not making smoking so seductive in Reality Bites, he wonders. "She's a role model for teenage girls, through and through, and she's smoking away."

Call them Hollywood's Pack Brats, basking in each other's secondhand smoke even as the national debate over cigarettes rages. Linked with cancer and heart disease, death, smelliness and even (what with the resulting rise in health-care costs) an increase in taxes, smoking is banned—or at least strictly regulated—in theaters, offices and restaurants (including those in L.A.). You can't smoke in the White House (Bill is allergic), let alone in a number of prisons. Between 1965 (the year after Surgeon General Luther L. Terry issued his landmark warning) and 1991, the percentage of American adults who smoke plummeted by more than half, to 25 percent.

No matter; in Hollywood movies the habit is still big. According to a 1993 study conducted by cardiologists at the University of California, San Francisco, the number of young smokers on the movie screen more than doubled in the past 30 years, while adult, educated smokers have been consistently over-represented—there are proportionately three times as many of them on the screen as in the national audience. Even now, at theaters near you, Susan Saran-don is bonding with a rough-and-tumble 11-year-old by sharing a cigarette in The Client. Jeff Bridges, as a police bomb expert in Blown Away, also blows out smoke. And Mel Gibson plans to star in the movie version of Thank You for Smoking, Christopher Buckley's satirical novel whose hero is a handsome tobacco lobbyist. "Mel likes the story because it takes on political correctness," says Keith Davis, head of development for Gibson's production company. "This lobbyist is a smart, charming, basically good guy who just happens to smoke."

For adults, who have pretty much decided whether they're going to be smokers or not, Gibson's character might be just that. But teenagers are another story. For them, charming—or appealingly angst-ridden—smokers can serve as missionaries for tobacco. Three million of the nation's 46 million smokers are teenagers, consuming nearly a billion packs of cigarettes a year; each day an estimated 3,000 teens take their first puff. Indeed, recent government statistics indicate that smoking among twenty-somethings has increased. Nudging them toward the habit are more than $4 billion a year in promotion and advertising. Government statistics released last month show that the three most heavily promoted brands, Newport, Camel and Marlboro, capture a staggering 86 percent of the teenage market.

That's without benefit of TV commercials, banned in 1971, or—so all tobacco representatives contacted for this article insist—cigarette companies paying to have their product "placed" in movies, a practice they agreed to end in 1990. (Although Buckley, for one, suspects that such fees continue to be paid to moviemakers coping with huge costs. "Any movie in which you can see a readily identifiable pack of cigarettes, you can smell more than smoke," he says. "You can smell a big, hairy rat.")

But many in Hollywood believe that, even with ads curtailed, images of stars smoking, whether onscreen or in their private lives, are sufficiently dangerous allurement. Which is why some show-business folks weave antismoking messages into movies and TV shows. Only the occasional misfit lights up on fox's Beverly Hills, 90210 or Melrose Place. On the new ABC teen-angst drama My So-Called Life, 15-year-old Claire Danes doesn't smoke, but the sultry boy she has a crush on does. So does her best friend's loudmouth mother. In one episode of James L. Brooks's cartoon series The Simpsons, greedy tobacco executives fling cigarette packs at kids. "I don't think anyone on the show smokes who's not dying from it," says producer Brooks. "Marge Simpson's sisters are clearly not long for this world."

Or consider: In the current movie Corrina, Corrina, set in 1959, child actress Tina Majorino hides dad Ray Liotta's cigarettes. In Angels in the Outfield, associate producer-screenwriter Holly Goldberg Sloan deliberately had the team's good guys chew gum, while one loser character smokes. "I try to make smoking a trait of the dark characters," says Sloan, the mother of two preteens. "That way kids can make the correlation linking an unattractive habit with an unattractive person."

But what about the onscreen smokers who are appealing? Joe Cherner, head of the nonprofit SmokeFree Educational Services of Manhattan, targets them in ads he places in such trade publications as Variety. "Your movies make smoking seem sexy, cool and grown up," he wrote to Christian Slater, 25, who inhaled throughout last year's True Romance. "Thus, unwittingly, you are the tobacco companies' best tool."

And yet Cherner (who says no star has responded directly to the ads) is himself a sort of target. After all, as anyone who has been through adolescence can recall, smoking is cool, in part, precisely because a bunch of adults keep telling you it's not. "Whenever something that's unhealthy is demonized, it becomes irresistible," says Richard Klein, author of Cigarettes Are Sublime, a meditation on the culture of tobacco.

Reynolds suspects the psychology is more complicated. "My gut feeling about Hollywood smokers is that many are ashamed of the fact that they're addicted," he says. In fact, not a single one of the smoking celebrities contacted by PEOPLE cared to discuss the topic. Are they truly enjoying their cigarettes? Mel Gibson suggests not. "He'd love to quit," says production associate Keith Davis, "but he can't. Like almost everybody, he has tried—but it's a tough addiction."

NANCY MATSUMOTO, CAROLYN RAMSAY and KAREN JACKOVICH in Los Angeles