The D.C. Lottery Board, in its push to start a city-run daily numbers game, may also unwittingly be providing help to the $250 million-a-year illegal game that has been flourishing for decades on the streets of Washington.

A one-sentence provision in the board's request for bids innocuously says the board "desires preprinted bet slips to be made available to customers."

Preprinted bet slips are pieces of paper on which bettors can mark the selection of several three-digit numbers and the combination of wagers they want to make in the hopes that one of those numbers will be chosen as the day's winner. The bet slips can then be inserted into a machine that will automatically read the card and print a ticket denoting which numbers the bettor has wagered on.

The bet slips will be available free to anyone at the 300 or more lottery ticket outlets throughout the city and therein lies the possible connection with the illegal numbers game. The illegal game, sometimes called "policy," has long been a part of Washington neighborhood life.

Arrests made in an effort to crack down on illegal numbers games often are for operating a lottery, with possession of numbers slips being one of the key pieces of evidence.

With the use of official, government-sanctioned bet slips, numbers operators would be able to tell police that their slips were meant for use in the legal game even if they were instead planned for use in the illegal game.

Sgt. Carnwell (Butch) Dean, head of the D.C. police department's gambling squad, said he was not aware of plans for the use of preprinted bet slips until a reporter informed him.

"There's no question it would have an impact on us," Dean said. "It would just give the illegal people another crutch to fall back on. If they've got 10 of those computer cards it would be pretty hard to make a case."

Police say that prosecutors and judges often give short shrift to cases involving the operation of an illegal numbers game, with prosecutors trying to get defendants to plead guilty to reduced charges and judges often imposing relatively small fines for convictions.

Despite the advent of the scratch-off lottery game in the District and the popular daily numbers game in Maryland, police say the illegal numbers industry here enjoys gross revenues of up to $250 million a year.

Illegal games often thrive side-by-side with legal games because the street game operated by the neighborhood "entrepreneur," as operators sometimes are called, often offers credit to gamblers or accepts bets of as little as a nickel or a dime. The government-run lotteries do not offer credit and require minimum bets of 50 cents.

The idea behind the preprinted bet slips, says Jerry Cooper, the lottery board member who recommended the bet slip provision, is to speed the sale of tickets and to eliminate human errors that occur when bettors read their bets to a clerk who then must punch the numbers into a machine.

"In the District of Columbia you've got many people who would like to play the numbers who don't want to wait in line and call out their numbers," Cooper said.

Cooper said he recommended the preprinted bet slips after viewing their use in Massachusetts and at horse racing tracks.

"I can't speculate on what the illegal operators might do with them," Cooper said.

"They won't have a terminal that would read them.

"They may use it as a cover," he said. "It won't make their activity any easier. In every one of these states where they have put in a legal game, there's been a thriving illegal game."

Cooper said that in any event, "I'm not trying to stop the illegal game. It never was the goal. It's been to raise revenue for the District of Columbia and to enhance retail sales" by selling the tickets in such neighborhood institutions as liquor stores and convenience shops.

"A bet slip will save time and time is money," said P. Leonard Manning, general manager of Lottery Technology Enterprises, the firm that was selected by the lottery board to operate the District's game before the decision was rescinded and new bids were solicited.

"I suppose it will be up to the courts to decide intent" on the use of the slips by those charged with being illegal operators, Manning said.

Only Massachusetts now uses preprinted bet slips in a daily numbers game, although the slips are also handed out in Lotto-type games there and elsewhere in which players try to pick six winning numbers out of 36 or more.

Massachusetts lottery spokeswoman Frances McDonnell said the "betting slips are really a convenience" for those who play the game and said she did not think the slips have proven of any value to those who run the illegal game.

She said, however, that she did not have any study to support her position.