A lottery is a form of gambling in which tokens are distributed or sold and the winning ones are selected by lot. It is often a means of raising funds for public or private projects. The drawing of lots to determine ownership or other rights is recorded in many ancient documents, including the Bible. In modern times, the term has come to refer to any contest whose outcome depends on chance, whether it is a game of skill like bridge or a competition where winners are chosen by chance such as the Olympic games. The lottery has become a fixture in American culture, with people spending billions on tickets each year.

Some states use the lottery to raise money for public schools, hospitals and other programs, while others promote it as a way to help children. However, despite these claims, the lottery is a costly form of government revenue. Most state budgets use about 40 percent of lottery proceeds for administrative expenses, compared with less than 20 percent for general spending. These costs are incurred in the form of commissions paid to lottery retailers, overhead for the lottery system itself and taxes on ticket sales. It is not clear whether this additional expense is worth the public benefit that state officials claim it provides.

Despite their high cost, lottery revenues are still an important source of state income. In the years after a lottery is introduced, revenues typically expand rapidly, and then level off or even decline. To maintain their revenues, lottery officials introduce new games to appeal to specific audiences. These new games may have different rules, prizes and odds of winning. They may also involve new types of gaming, such as scratch-off tickets or combinations of numbers.

In most cases, the public is not aware of how much the lottery costs or how the prize amounts are determined. Moreover, lottery advertising is sometimes misleading, with advertisements touting the highest jackpots and the percentage of the pool that is returned to players. Critics charge that these promotions are misleading and euphemistic, but most states do not have enforceable regulations on lottery advertising.

Many lottery critics contend that the industry has created a complex network of special interests that benefit from the lottery. These include convenience store operators (the primary lottery vendors); suppliers of equipment and services for the lottery; teachers (since a large percentage of the proceeds is earmarked for education); and politicians, who benefit from state tax dollars that are diverted away from their regular budgets.

Some of these interests are clearly legitimate, but it is possible that some are not. For example, lottery revenues provide funding for education and gambling addiction initiatives, but critics point out that there is no evidence that these efforts are effective. In addition, the lottery supports a large group of politically well-connected businesses that contribute heavily to election campaigns and lobby for more lottery funding. These favored business interests are often more powerful than voters in determining lottery policy.