Lottery is an arrangement for awarding prizes in which the allocation of the prize is based entirely on chance. It can be regarded as a form of gambling because the participants are betting against each other in exchange for a possible future monetary gain, although the entertainment value and other non-monetary benefits of lottery participation may also outweigh the disutility of losing money, and therefore the purchase of a ticket is a rational decision for some individuals.

It has a broad appeal as a method of raising funds for public purposes. In colonial America, for example, a great number of lotteries were sanctioned and played a major role in financing private and public ventures including roads, canals, bridges, churches, schools and colleges. Lotteries were also important sources of funding for the American Revolutionary War.

The earliest known records of a lottery date to the Chinese Han Dynasty between 205 and 187 BC. These records show that people used a variety of methods to distribute property and other assets by lot, such as the keno slips mentioned earlier.

In addition to a process for allocating the prizes, a lottery must also have some means of recording the identities and amounts staked by the bettors. This can take the form of a simple list that is compiled by the lottery organization, or it can involve more sophisticated techniques such as a computer-generated record. The bettor’s name and other information may then be inserted into a pool of numbers, which is subsequently shrunk for the drawing. A percentage of this pool is typically set aside for expenses and profits, so that the remainder is available to the winners.

Most lotteries are run by governments or other organizations that have a legal right to raise funds in this way. These entities usually establish a state-based corporation to administer the lotteries and impose rules that govern their operation. In many cases, the company in charge of a particular lottery is required to conduct an independent audit to ensure that all games are operated fairly and in accordance with applicable laws.

Lottery participants tend to be more likely to come from middle-income neighborhoods than those of lower income. This may be because lower-income areas have fewer recreational and educational opportunities than upper-income neighborhoods do, so they are less likely to be able to afford a subscription to a computerized lottery.

The success of any lottery depends on its ability to attract sufficient numbers of participants to make it economically viable. To do this, it must offer a large enough prize to create an incentive to participate. This can be accomplished by offering either a single, very large prize, or a number of smaller prizes, or both. To increase the chances of winning, some bettors buy multiple tickets. Others, like Romanian mathematician Stefan Mandel, seek to win by assembling groups of investors who collectively purchase all the tickets needed to cover every combination of numbers. This is an expensive strategy, and even Mandel only kept $97,000 of his $1.3 million prize after paying his investors.