The casting of lots to make decisions and determine fates has a long history, with occurrences recorded in the Bible and by Roman emperors. But lotteries in which participants gamble for a prize of money are only moderately older, with the first recorded public lotteries to offer cash prizes appearing in towns in the Low Countries in the 15th century, raising funds for town fortifications and helping the poor.

A few basic elements are necessary for a lottery: a means of recording the identities and amounts staked by bettors; some method of selecting winners; and a pool of money from which the winnings are drawn. Typically, some percentage of the pool is set aside to cover costs and profits for the organizers and sponsors; the remaining sums are distributed as prizes. The size of the prizes varies. The larger the jackpot, the more interest is generated, but potential bettors must also weigh the likelihood of winning against how much they could spend.

The popularity of lotteries is often linked to state governments’ need for revenue without imposing especially burdensome taxes on working people. This was true in the post-World War II period, when states could use lotteries to expand social safety nets and avoid cutting back on public programs that were popular with voters. But it’s been less true in more recent years, when many of these same states have found that their lottery revenues have begun to level off. This has led to the proliferation of new types of gambling games and increased promotional efforts. The resulting mix of incentives has produced a number of challenges.