In modern lotteries, participants pay a small amount to have their names entered into a drawing for a prize, the value of which depends on the number of tickets sold. Generally, the prize is money or goods. Some governments outlaw the lottery, while others endorse it and regulate it as a form of gambling. In the United States, state lotteries are a popular source of revenue for government projects and agencies. The lottery is one of the few forms of legal gambling that is regulated at both the federal and state level.

The casting of lots to decide fates or property has a long record in human history, with several examples in the Bible. The first public lottery was organized in Rome during the reign of Augustus Caesar for the purpose of repairing municipal buildings. Lotteries are also common in sports, where players pay a small sum for the chance to win big prizes. In the United States, colonial settlers introduced lotteries to raise funds for new settlements and other projects. They also used them to give away land, slaves, and military service appointments.

Lotteries have a broad base of public support, although they are criticized for the effects on compulsive gamblers and their regressive impact on low-income households. Despite these criticisms, the lottery is a powerful force for raising revenue, and its popularity and growth have prompted debates about how to manage it responsibly. Most lotteries are run by a state agency or public corporation, and they start operations with a modest array of games and a small prize pool. They are quickly forced to expand, however, due to pressure to increase revenues, and this expansion is fueled by a heavy advertising campaign.