SOME PEOPLE PLAY New Year's Eve Roulette: They call around at the last minute to find a restaurant with more cancellations than overbookings.

Others play the opposite game: They make a reservation for New Year's Eve at several restaurants and decide the last minute which they want to use or whether they want to go out at all. The restaurants, in response, overbook and risk having to squeeze in extra diners. And many of them suffer financially when half of their fully booked dining room stands empty while the band plays on.

The rules have been changing, though. Not only is New Year's Eve one of the busiest times for a restaurant, it is an expensive production. Staffing costs more, and many restaurants go to the expense of buying party hats and favors and hiring dance bands. Thus, it is frustrating to spend weeks turning down requests for reservations, only to be left with a sea of empty tables. Restaurants are learning to protect themselves from no-shows and to let the customer (or non-customer) bear the price.

Some restaurants are demanding full payment at the time of booking. Plata Grande in Calverton had already caught on by last year when it required New Year's Eve customers to buy tickets ahead of time. They could be refunded only if someone on the waiting list was willing to buy them. The Mayflower Hotel downtown, which is hosting four different New Year's Eve parties, has a different policy for each. Its big bash, the Diamond Ball, is requiring full prepayment. The evening includes music, dancing, a five-course dinner and an early-morning buffet, for $122.75 per person including tax and tip, completely paid at the time of booking. Cancellations are possible up to about two days in advance.

Obviously full prepayment solves the empty-table problem and even assures that the waiter won't lose tips from no-shows. Few restaurants go so far, though this year many are growing bolder in requiring non-refundable deposits. Aux Beaux Champs in the Four Seasons Hotel requires a deposit of $50 except from hotel guests and allows refunds only up to three days in advance. The Alibi in Fairfax is requiring a deposit by credit card or cash for its $75 six-course dinner with dancing, wine and champagne, party hats and favors. The deposit is refundable up to 24 hours ahead.

Joe & Mo's three restaurants are also planning to require deposits, but have not yet settled on the amount. They've been asking advice on whether to make it 25 percent of the cost of the evening or equivalent to the waiter's tip. They will allow refunds up to 48 hours ahead. Morton's of Chicago, in Georgetown, will this year, for the first time, require a $20 per person deposit for its 10 p.m. seating; cancellations are refunded up to Dec. 28, and the regular menu will be in effect.

Mrs. Simpson's on Connecticut Avenue accepts New Year's Eve reservations only with a credit card guarantee and a home phone number, but doesn't require specific deposits. Instead, the restaurant calls every reservation on Dec. 31 to reconfirm and suggests people with reservations call in to reconfirm if they haven't been reached by the restaurant. If the restaurant does not get a telephone confirmation it gives away the table (another winner for New Year's Eve Roulette).

Mrs. Simpson's is also preparing a more low-key celebration than ever before, which is another pattern appearing this year. It will offer hats and horns to the revelers, along with "a little surprise," said proprietor Jason Wolin, but it is not buying fancy ingredients or hiring a band. "I'd rather not deal with it," said Wolin; the regular menu will be in effect.

Some restaurants resist inflicting deposits on its customers. Fedora's general manager Dan Mesches declared, "We're not having anything to do with deposits." But the restaurant will cancel any reservations not reconfirmed by phone. "We will phone assiduously" before cancelling, promised Mesches, who added that Fedora, like many restaurants, overbooks for New Year's Eve to compensate for no-shows (12 to 20 percent at that restaurant).

Jean-Louis at the Watergate, like Mrs. Simpson's, Morton's and many other restaurants, is more low-key, too, with no music or favors -- but with a $10 to $15 price increase over its regular fixed-price dinners. It requires no deposits; they are too complicated and don't work, declared mai~tre d'hotel Alain Matrat. Instead, the restaurant calls every reservation to confirm and cancels if the diners can't be reached. That works, said Matrat, adding, "We really spend time on the phone."

In sum, while dining out costs more than ever this year, not dining out is also going to cost more. And in many culinary circles, probably reflecting financial circles, ringing out this old year is going to be less with a bang than a whimper.