Lottery is a form of gambling that offers the chance to win money or prizes based on randomly chosen numbers. State lotteries have proliferated throughout the United States, with Americans spending more than $100 billion each year on tickets. Although there are some state-level issues with lottery operations—including the potential for problems with low-income and problem gamblers, and the extent to which public funds are used to promote gambling—lotteries have generally been successful in generating substantial revenues for their participating governments.

The modern era of state lotteries began in 1964, with New Hampshire being the first to introduce one. Following New Hampshire, several other states soon adopted their own versions. Since then, the development of lottery laws and their operation has followed a predictable pattern: states legislate a state monopoly; establish a public agency or corporation to run the lottery (as opposed to licensing private firms in return for a share of profits); begin with relatively simple games; and, driven by constant pressure for additional revenues, progressively expand the number and complexity of offerings, particularly through the addition of keno and video poker.

In the United States, many state-run lotteries have achieved a level of popularity that would make them rival the popularity of video games and even casinos. While most people who play the lottery are not necessarily addicted, they do often develop a habit of buying tickets regularly and spend significant amounts of time thinking about winning numbers.