The lottery is a form of gambling in which people purchase chances to win a prize based on the drawing of lots. The lottery has a long history of use, with the casting of lots occurring throughout human history, including several instances in the Bible. In modern times, state governments have adopted the lottery to generate revenue without onerous taxes on their residents. Lottery critics argue that the money generated by the lottery goes to addictive gambling habits, is a significant regressive tax on lower-income groups, and leads to other social ills.

Regardless of the arguments for or against state lotteries, their introduction has followed remarkably similar patterns: a state legislates a monopoly; establishes a public corporation or agency to run the lottery (rather than licensing private firms in return for a share of the profits); starts with a small number of relatively simple games; and, under pressure to maintain or increase revenues, progressively expands the lottery into new games.

Purchasing lottery tickets cannot be justified by decision models based on expected value maximization, as the ticket costs more than the expected winnings. However, many people continue to purchase lottery tickets, either because they do not understand the mathematics or because the entertainment value and fantasy of becoming rich is worth the cost. In addition, many people believe that buying more tickets increases their odds of winning; but in fact, the average lottery winner keeps only about 97,000 of the jackpot after paying investors.