Assessing the severity of problem gambling has been difficult. Measuring the increase in friendly poker games is a far cry from determining how many teenagers are brooding over their losses or selling their parents' possessions to pay off debts. Researchers who have completed studies on gambling estimate that 4 to 8 percent of adolescents suffer from a gambling problem, in varying degrees.

Many of the gambling counselors want the state Department of Education to institute mandatory gambling education statewide, but the department has opposed it, saying that local districts should tailor their health and physical-education classes to meet local needs. The state's curriculum standards already refer to gambling ''and helping students learn the negative effects of gambling over time,'' said Richard Vespucci, a department spokesman.

(Photo by Phil Marino for The New York Times)(pg. 1); Show me the money: Television has been one of the prime players in the poker fad. Teenagers admire gamblers like [Greg Raymer], left, who won last year's World Series of Poker, which was shown on ESPN, and they watch shows like ''Celebrity Poker Showdown,'' above and below, which is broadcast on Bravo.; [Ed Looney], executive director of the Council on Compulsive Gambling of New Jersey, with parents and teachers at Marlboro High School last Wednesday. (Photographs by Suzy Allman for The New York Times [above]; Image Masters Photography/ESPN [below left]; Paul Drinkwater/NBC [below right]; Justin Lubo/Bravo [bottom right]; and Laura Pedrick for The New York Times [bottom left])(pg. 8)

TEENAGERS are experts at hiding their intentions, connoisseurs of the little white lie. That can make them a pain in the neck to their parents. It can also make them good poker players.

Those sulky, shifty eyes may not be a big help when they are asked what time they came in the night before, but they come in handy when they are dealt a pair of aces -- or ''pocket rockets'' -- and they literally don't want to tip their hand. Those skillfully hooded eyes, however, also might be cloaking something else: a gambling problem.

Spurred by television and the Internet, poker -- particularly the game of Texas hold 'em -- has soared in popularity among teenage boys. They are playing online, at each other's houses and organizing tournaments modeled on the World Series of Poker. Can you hear New Jersey shuffling?

The upside is that poker improves math skills and the ability to read people, and creates a sense of community among teenage boys. But there is also a dark side that is forcing parents to grapple with difficult decisions. What does the mother from Bergen County do when she finds her son at home at the computer, playing poker online at noon on a school day? And what does the father -- who was once a gambler -- do when he realizes that his son is playing cards all the time, and losing badly?

''This year, in particular, the Texas hold 'em craze has just taken over,'' said Terry Elman, the education coordinator for the Council on Compulsive Gambling of New Jersey, a nonprofit group in Hamilton that is partly financed by the state. ''We are getting calls from schools that we never got calls from before, and the sound of concern in the voice of the student-assistance counselors or school principals who call is just enormous.''

In New Jersey, as in other states, gambling experts say that many more young people -- preteens, teenagers and those in their early 20's -- are playing poker than ever before, and more of them are getting into trouble. The number of people under 21 who called into the council's gambling hot line doubled between 2002 and 2004, with more than 3,500 calls in 2004.

Counselors have set up intensive prevention programs in three New Jersey schools, including Atlantic City High School, where gambling was out of control. Casinos are catching more teenagers trying to gamble; in Atlantic City they caught 384 underage people gambling last year, an increase from 2000, when 274 were caught. At Mainland Regional High School in Linwood, teachers and administrators have found students gambling with as much as $80 in the halls.

And, counselors say, the students are accumulating debt. A 16-year-old from the Princeton area owed more than $10,000. And a 12-year-old from Patterson owed $300 and was afraid to go to school.

At the same time, in communities where drugs and alcohol have wreaked havoc, poker can seem like a healthy activity. When you're playing poker, you don't drink or do drugs -- if you want to win.

There is plenty of evidence that gambling is growing.

A nationwide study released earlier this month by the Annenberg Public Policy Center of the University of Pennsylvania indicates that card playing is increasing among young people. The center surveyed 1,501 subjects between the ages of 14 and 22 and found that more high school and college students are playing cards. In 2004, 10.8 percent of the high school boys surveyed said they played in card games at least once a week, compared with 5.7 percent of those surveyed in 2003. And while only 3.3 percent of high school girls participated in weekly games, that also was an increase from 2003, when 1.5 percent played.

The study was also notable for another reason: researchers found that teenagers and young adults who were enrolled in school were more likely than those who had dropped out or found jobs to bet on cards. ''It all gets transmitted through the school culture,'' said Dan Romer, a senior research fellow at the Annenberg center.

Spurred by Television

Parents say they are surprised by how quickly the game has spread. ''We thought it was just happening in our town,'' said Susan Reed, of Haddonfield, the mother of a 15-year-old and an 11-year-old. ''I would go to a friend's house in the summer, and her kids would be playing poker in the basement. And I'd say, 'Your kids are playing poker, too?'''

Teenagers say that poker became popular about two years ago, and interest continues to surge. ''All my friends were playing it, and it got really popular on TV, so we all just started playing,'' said Jon Reichstein, 16, from Montclair. ''Last year, it was really getting big, and it's still growing.''

Others say that poker gives them a way to bond with friends, often without spending a lot of money. ''It's a cheap way to have fun with your friends,'' said Kellen Hayes, 17, from Haworth. ''It probably costs just as much to go to a movie as it does to hang out with your friends and play poker.

''I think it's something more and more kids are getting interested in. I think it's just going to get more and more popular as it expands into the new generation.''

Teenagers are taking their cue from the popularity of poker shows on cable television, gambling experts say. The World Series of Poker on ESPN, the World Poker Tour on the Travel Channel and ''Celebrity Poker Showdown'' on Bravo have a created a new cadre of high-stakes media stars like Doyle Brunson, Dan Harrington, Daniel Negreanu, Greg Raymer and Johnny Chan.

The teenagers' cult film of choice is ''Rounders,'' a 1998 poker movie with Matt Damon and Edward Norton. And then there's the ease of playing poker on the Web; Internet gambling, including poker, has blossomed into a multibillion-dollar industry.

The popularity of the television shows has drawn concern from at least one politician. Assemblywoman Joan Voss, a Democrat from Fort Lee, has proposed a bill that would authorize a surcharge on cable companies that carry certain programming promoting gambling.

''These cable companies are making a tremendous amount of money because these shows are so popular,'' she said in a recent interview. ''I would like them to put something aside of their own volition to address problem gambling.''

The teenagers interviewed for this article say they know how to control their behavior when it comes to poker. ''I think we all understand that losing is a part of it,'' said Matthew Cherchio, 16, from West Orange.

But experts say that not every teenager can achieve that balance.

Assessing the severity of problem gambling has been difficult. Measuring the increase in friendly poker games is a far cry from determining how many teenagers are brooding over their losses or selling their parents' possessions to pay off debts. Researchers who have completed studies on gambling estimate that 4 to 8 percent of adolescents suffer from a gambling problem, in varying degrees.

The Diagnostic and Statistical Manual of Mental Disorders, considered the definitive guide to psychiatric disorders, lists 10 criteria to determine if someone is a problem gambler, including whether the person becomes completely preoccupied while gambling or fails repeated attempts to cut back on their play. People who say they experience at least five of the criteria are considered pathological gamblers. Those with three or four criteria are generally considered problem gamblers at risk of developing more serious addictions.

Concerns about teenage gambling are not entirely new: the Council on Compulsive Gambling of New Jersey has been called into schools since the 1980's. Nowadays, it is called into as many as 60 or 70 schools every year.

The council has even begun seeing gambling problems in younger children.

''This year we're starting to see the trend start lower than high school,'' said Ed Looney, the council's executive director. ''The kids are starting to gamble earlier and they're having problems earlier.''

The council's hot line takes thousands of calls from people concerned about their own gambling problems or the problems of their loved ones. Between 2000 and 2002, 2 percent of the calls were for gamblers under 21; in 2003, they accounted for 5 percent of the calls; and last year, they accounted for 6 percent, or about 3,500 calls, Mr. Looney said. He added that not all the hot line's calls come from New Jersey.

Arnie Wexler, a gambling counselor from Bradley Beach who runs a national gambling hot line and is a recovering compulsive gambler, said that he has seen an increase in adolescents with gambling addictions.

''I'm not going to tell you I didn't deal with kids 20 years ago, but it's much bigger today than it ever was,'' he said. ''There's no question in my mind that more kids are asking for help.

''They're stealing it, they're taking money from their parents, they're using their lunch money, some of them are selling drugs to support their habit. I know college kids who have gotten loans and grants and have used the money to gamble.''

Addicted at a Younger Age

Mr. Wexler said that he thinks adolescents and young adults are the fastest-growing segment of gambling addicts. He estimated that 10 to 12 percent of people calling hot lines in this country are younger than 25. ''I'm getting e-mails from all over the country to come and speak because this thing has exploded in the high schools,'' he said.

Other gambling counselors in New Jersey tell similar stories. Lenny Braver, a counselor in Rockaway, said that he has seen rapid growth in the number of adolescents with gambling problems.

''Last year, I saw no adolescents at all, and this year I've had at least five,'' he said. ''The youngest I saw was 15, and the oldest 19. The other day, I had a patient I was seeing and she was telling me about her granddaughter who was in school and she was reprimanded by the teacher for playing poker for Oreos.''

Many of the gambling counselors want the state Department of Education to institute mandatory gambling education statewide, but the department has opposed it, saying that local districts should tailor their health and physical-education classes to meet local needs. The state's curriculum standards already refer to gambling ''and helping students learn the negative effects of gambling over time,'' said Richard Vespucci, a department spokesman.

Gambling counselors say that parents and school administrators do not always recognize the signs of problem gambling. Parents often don't notice until their credit card is gone or their children are in trouble in school, counselors say. And with the increase in the number and popularity of online poker sites, adolescents can lose money to people all over the world.

One mother from Bergen County, who asked not to be identified, said that her 17-year-old son sometimes played poker on the computer from 3. until 11 p.m. She initially allowed him to use her credit card to play, and he repaid her, but she later found that he had been spending more on the card than she thought, and she has since monitored him more closely. She said that she is confused about how to deal with her son's gambling.

''I did threaten to take him to the Gamblers Anonymous meeting,'' she said. ''He didn't want to go. He said: 'They're a bunch of idiots there. They're gamblers who have lost their homes. They're losers.' What he doesn't understand is that they started just like him.''

Another Bergen County mother, who also asked not to be identified, said her 16-year-old played online for hours at a time; she worried that he had begun to follow in the footsteps of his father, who was a gambler. At first, it seemed like a healthy habit. The boy had impressed his friends and their parents with his ability to grapple with poker percentages. He even wrote a paper on the statistics of poker for his math class, she said. But as he became more interested in the game he began to play online and it dominated his free time. ''The computer was overwhelming, for hours and hours and hours,'' she said.

Eventually, she said, he lost about $1,500.

''He was looking for money all the time: 'You owe me money for this. You owe me money for that,''' she said. ''He was angry, bitter, agitated, and he's not normally an agitated kid. He was rushing home to get to the computer, wrapping his days around the game.''

The ordeal has left her baffled and upset.

''You're thinking you're doing a good deed because your kid's not out partying on the weekends,'' she said. ''They're not losing their houses. They're not losing their jobs. They don't have bills to pay, but they're all almost 18 and we've got gambling in the state of New Jersey.''