Lottery is a popular form of gambling in which players purchase tickets for a drawing to determine the winners. Various prizes may be awarded, including cash or goods. Prizes are typically distributed by state governments or private companies, and the proceeds are used to fund public projects such as roads and schools. Lotteries are legal in most countries and have long been an important source of revenue.

The casting of lots for money or other goods has a long history, but the modern lottery originated in the early 16th century in Europe. In 15th-century Burgundy and Flanders, towns held lottery-like events to raise money for poor relief. By the end of the century, most European nations had government-run lotteries.

Lotteries are a classic example of how public policy develops piecemeal and incrementally, without a clear overall vision. After a lottery is established, the officials who oversee its operations have a wide range of specific constituencies to please: convenience store owners (who sell the tickets); lottery suppliers (heavy contributions to state political campaigns are reported); teachers (in states where lotteries are earmarked for education); and the public at large (which quickly becomes accustomed to additional tax revenues).

Although the odds of winning a lottery are low, many people believe that they will become rich someday with just one ticket. This belief is partly driven by peer pressure, because people feel that their friends are also playing the lottery. It is also fueled by brain chemicals such as norepinephrine and serotonin, which increase during emotional stress or in response to boredom or deprivation.