A lottery is a game in which people purchase chances, or tickets, for the chance to win a prize. The prizes may be cash or goods. In the case of the games that award cash or merchandise, the winnings are determined by drawing numbers from a pool of entries. The drawing is conducted by an independent entity that ensures that the process is fair. Other safeguards include video surveillance of the process and tamper-evident seals on entry forms. Many states have strict rules about how the winnings are distributed.

The casting of lots to determine fates has a long history, and modern lotteries often employ the same procedure to distribute money or goods. Whether or not these events are considered gambling, however, depends on the payment required to participate. In the strictest sense, only those instances in which a consideration is exchanged for a chance to receive a prize are classified as a lottery. Such examples include military conscription, commercial promotions in which property is given away by a random procedure, and the selection of jury members.

Many state governments regulate their own lotteries, although private firms also operate them under contract to do so. Regardless of who runs a lottery, most follow a similar model: a government legislates a monopoly for itself; establishes a public corporation to run it (as opposed to licensing a private firm in return for a share of the profits); begins operations with a modest number of relatively simple games; and then, under pressure from the need to generate additional revenue, progressively expands the operation by adding new games.

In addition to traditional lotteries that distribute money or goods, some states also offer a variety of other games such as keno and video poker. These games are not considered gambling by the state, but they do expose players to the risks of compulsive gambling and, in some cases, addiction.

Lottery plays an important role in many states, providing a source of tax-free revenue that is seen as contributing to a broad range of social and public services. In most cases, the public accepts the need for state lotteries to raise funds for specific purposes and is willing to pay a small percentage of income to do so. Lottery revenues have also proven to be resilient in periods of economic stress.

Even so, there are serious concerns about the operation of state lotteries, including their tendency to promote addictive behavior and their regressive effects on lower-income groups. There is also a question about whether it is appropriate for governments to be in the business of promoting gambling. In spite of these criticisms, the majority of state legislatures approve lotteries. The decision to do so is driven by voters who wish to see more spending on a particular cause and by politicians seeking painless revenue without raising taxes or cutting popular programs. These arguments are not influenced by the state’s objective fiscal health, as demonstrated by the fact that lotteries have won broad approval even when state government finances are in good shape.