A lottery is an arrangement in which one or more prizes are allocated to individuals by a process that relies on chance. It has become popular for raising public funds in a variety of situations, such as building roads and bridges or providing assistance to the poor. In the United States, 43 states, the District of Columbia, and Puerto Rico have lotteries.

In most modern lotteries, a ticket buyer marks one or more boxes on a playslip to select numbers from a range of possibilities. The computer then randomly picks the winning numbers for that drawing. Some lotteries offer only one draw per day (Pick Three, for example), while others have multiple draws throughout the week.

Typically, the costs of organizing and promoting a lottery must be deducted from the pool of prizes, leaving a percentage for prizes to winners. Moreover, the prize pool must be balanced between a few large prizes and many smaller ones. The latter attracts more bettors, but a lottery must also keep in mind that it can be difficult to award large prizes, and that people who participate in lotteries tend to play them a substantial number of times.

The first recorded lotteries were held in the Low Countries in the 15th century to raise money for town fortifications and aid to the poor. The lottery was an instant success, and its popularity quickly spread to other countries. Many lotteries are now held to fund a wide range of public projects, and have developed a broad base of support that includes convenience store owners, lottery suppliers (whose large contributions to state political campaigns have become known), teachers (in states in which the revenues are earmarked for education), and the general public.