Lottery is a form of gambling in which people purchase tickets for a chance to win a prize, usually money or goods. The casting of lots for making decisions and determining fates has a long history, including several cases in the Bible, but public lotteries in the modern sense of the word first appeared in 15th-century Burgundy and Flanders, where they were used to raise funds for town defenses or for charity. A lottery is considered a gambling activity under federal law and must be conducted on a public scale, with payment of consideration (usually money) for the opportunity to receive a prize based on a random drawing or matching of lucky numbers.

Most state lotteries operate under the same basic structure, with the winner selected by random drawing from a pool of ticket sales and other sources of revenue. The prize fund may be a fixed sum or a percentage of total receipts. A common format is to have multiple prizes in a single game, such as the popular Powerball.

Despite their popularity, lotteries have a number of significant problems that are difficult to resolve. For one, revenues typically expand dramatically after a lottery’s introduction and then level off or even decline. This has led to a relentless cycle of innovation in which new games are introduced in an attempt to maintain or increase revenues. The reliance of state governments on this source of funding also presents issues. Various studies have shown that the bulk of lottery players and revenues come from middle-income neighborhoods, with a significantly smaller share from low-income areas.