A lottery is a game of chance in which numbers are drawn at random and prizes are awarded to the holders of tickets with those numbers. It is often used as a method of raising money for public or private ventures, including schools and colleges. It is also used to allocate limited resources such as seats at reputable universities or housing units in a subsidized apartment complex.

Initially, state lotteries were little more than traditional raffles in which people bought tickets for future drawing, often weeks or months away. After the 1970s, however, they evolved into instant games such as scratch-off tickets. These offered lower prize amounts, but higher odds of winning. Almost all states now sell instant games, which can be purchased at convenience stores, bars and restaurants, gas stations, bowling alleys, and newsstands. The National Association of State Lottery Directors (NASPL) reported that in 2003 nearly 186,000 retailers sold lottery tickets, with the largest number being in California.

While some lottery players believe that they have a system that will help them win, most go in clear-eyed about the odds. They may have quotes unquote about lucky numbers and lucky stores or times of day to buy tickets, but they know that the odds are long and they are likely to lose.

Lotteries are one of the classic examples of a policy made piecemeal and incrementally, with only intermittent consideration of the general welfare. In the case of the lottery, this means that officials become dependent on revenues from a source that they can do little to influence.