A lottery is a form of gambling where numbers are drawn for a prize. Some governments outlaw it, while others endorse it and organize state or national lotteries. Some even use it to raise funds for public services. While some people have won big prizes, most have lost money. Nevertheless, many people continue to buy tickets and play the lottery for the entertainment value. According to the utilitarian theory, a person may rationally purchase a ticket if the expected entertainment value exceeds the disutility of a monetary loss. This is true even when the odds of winning are extremely low.

Lotteries are easy to organize and popular, making them an effective means of raising money for a variety of purposes. They are also less controversial than direct taxation, which is more likely to provoke political opposition. In the 17th century, for example, lotteries were used to fund a wide range of projects, including the building of the British Museum and the repair of bridges. Benjamin Franklin held a lottery to raise money for cannons to defend Philadelphia against the British.

The state-run lottery is the oldest. Today, most states and Washington, D.C., offer different kinds of lottery games, from instant-win scratch-offs to games where players pick a group of numbers. The odds of winning depend on the number of tickets sold and the total pool of numbers available for selection. Experts advise avoiding picking numbers that end in the same digit and avoiding groups of numbers that have been winning numbers in previous draws.