The law, which takes effect Wednesday, allows police to charge minors with a misdemeanor and a $100 fine if they are caught on gambling floors. Using forged IDs to get on gambling floors could result in fines between $100 and $500 and 30 days in jail.

Minors always have been forbidden from gambling floors, but state and tribal officials gathered in the Legislative Office Building at the state Capitol said the new provisions would help enforce the existing prohibitions.

"That has always been the law," state Rep. Andrea Stillman, D-Waterford, said. "Now we have an opportunity to make the law more meaningful."

The newspaper ads pull no punches, featuring school yearbook-type photos superimposed over shots of people being booked or being placed in prison. In a radio spot, a speaker who sounds as if he's smoked one cigarette too many warns teens of the risk of jail.

"What if you start crying?" the voice says. "What if your mom starts crying?"

The number of young people gambling at Mohegan Sun is relatively small, Mohegan tribal chairman Mark Brown said, but the casino wanted to take steps to control the problem and provide adequate measures to punish teen-agers who try to gamble.

"It hasn't been a problem at all," Brown said. "But you want to proactively address it as it comes."

Studies conducted by the Connecticut Council on Problem Gambling suggest that teenagers are a particularly high-risk group for compulsive gambling.

Approximately 11.3 percent of college-age adults are known to have compulsive gambling problems, with a comparable rate for high school students, said Marvin Steinberg, executive director of the organization.

"This is an at-risk group, and this past year, we did a study of clinical agencies, the point being that there aren't enough trained clinicians to deal with minors," he said.

The $150,000 ad campaign will run through the state over the next two months; the casino then would revisit its effectiveness afterward, said Tom Bradley, director of public relations for Mintz & Hoke, the firm that designed the campaign.