Kansas City, Mo. ? Bet more, get more. Free meals. Free rooms. Free cash.

OK, so they’re not exactly free. They’re “comps” — and for years, casinos have relied on the system of discounts or outright giveaways to inspire gamblers’ loyalty and provide losing players with a reason to come back for one more shot at a jackpot.

Now, an experimental program at Harrah’s North Kansas City Casino is sweetening the pot, offering additional cash rebates to some slot and electronic poker players in an effort to spur action on traditionally slow Mondays and Tuesdays.

The program is only scheduled to run through May but could be extended if it proves successful, casino officials said.

“I think it’s like any other entertainment business,” said David Strow, a spokesman for Las Vegas-based Harrah’s Entertainment Inc., the world’s largest gambling company. “You have periods of higher demand and periods of lower demand, and we want to pick up business in the periods of lower demand.”

Anti-gambling groups, however, call the program “predatory” and say it targets those most likely to become problem gamblers.

“They talk about Missouri casinos as entertainment, but this has nothing to do with entertainment,” said Mark Andrews, chairman of Casino Watch, based in the St. Louis suburb of Chesterfield. “It’s a predatory practice. It’s not about getting people to be entertained. It’s about getting people to drop more money.”

The program uses a player’s club card to track a gambler’s level of play, which Harrah’s and other casinos already do to determine what comps a player has accrued. Harrah’s holds a number of patents in that area.

In Missouri, where state law limits a gambler’s losses to $500 every two hours, casinos also use the cards to make sure players do not exceed that amount. But while a gambler must insert the card into a machine before playing, reward points only accumulate if the card is left in while gambling.

Players who gamble at least $50, win or lose, on a Monday or Tuesday will be mailed a voucher with a cash value of 10 percent of the total amount wagered that day, up to $20 — 10 percent of $200.

Those vouchers can then be redeemed for cash at the casino. Meanwhile, players will also accrue points toward rewards under the regular comps program.

The North Kansas City location was chosen, Harrah’s spokeswoman Jan Jones said, because of the intense competition between the Kansas City area’s four casinos. Harrah’s announced the program through promotional mailings.

Construction on the slots floor made it difficult to assess gamblers’ response to the program on its first two days, Strow said.

Once the rebate vouchers start arriving in players’ mailboxes, anti-gambling groups expect them to be cashed, then gambled away — leading players to risk even more money to try to recoup their losses.

“It always becomes the next pull that’s going to allow them to catch up and get ahead,” said David Robertson of Cody, Wyo., a board member of the National Coalition Against Legalized Gambling. “They’re always chasing their losses.”

Harrah’s excluded table games from the rebates, Strow said, because electronic games make up the majority of its business. The casino has more than 1,800 slots, ranging from penny machines to those with a minimum bet of $25.

But slots players are more likely to become problem gamblers than those who play table games, Robertson said.

“Those are the crack cocaine of gambling,” he said. “With betting on horse races or blackjack, it usually takes a gambler seven years before he reaches bottom. With video poker and slots, it only takes 3 1/2 years, and some people do it in a year’s time.”

Casinos counter that they do what they can to deal with problem gambling, noting that the Missouri Riverboat Gaming Association funds the 1-888-BETSOFF program. The hotline and Internet site allow problem gamblers to exclude themselves for life from the state’s casinos and provides referrals to counseling agencies.

A 2004 report on gambling in Missouri, the most recent report available, found an increasing number of problem gamblers doing so. Also in 2004, a Harvard study found that about 39,000 Missouri residents — most of them in Kansas City and St. Louis — experienced a serious gambling problem in the previous year.

Those who ban themselves from casinos aren’t supposed to receive mailing promotions either. But last year, the state fined Harrah’s North Kansas City Casino $40,000 for marketing violations that included mailing promotional materials to people on the excluded list.

The casino paid the fine without appeal and said it would fix the problem.