Official lottery is a form of gambling in which many people purchase chances to win money or goods through a drawing based on luck. The prize money may be a fixed amount of cash or merchandise, or it may consist of a percentage of the total ticket sales. In addition, costs of organizing and promoting the lottery must be deducted from the prize pool, leaving a smaller share available for the winners.

The first recorded lotteries, with tickets for sale and prizes in the form of money, were held in the Low Countries in the 15th century. Town records in Ghent, Bruges, and other cities reveal a number of public lotteries raising funds to build walls, town fortifications, and charity. Benjamin Franklin held a lottery in 1776 to raise money for cannons for the defense of Philadelphia. George Washington managed a private lotteries in the American colonies, offering land and slaves as prizes in his Mountain Road Lottery of 1769.

In modern times, state lotteries advertise their games with the slogan “You could be rich!” The messages are intended to reassure players that winning is possible and that playing the lottery is safe. State lotteries also stress the benefits of the money they raise for state governments, despite the fact that a very small percentage of ticket sales goes to state coffers. Despite the positive messages, state lotteries are not a good way to promote responsible gambling, as they tend to skew heavily towards poorer players who have the fewest resources to cushion any losses.