A lottery is a gambling game or method of raising money, as for some public charitable purpose, in which a large number of tickets are sold and a drawing is held for certain prizes. Lotteries are typically organized so that a percentage of the profits is donated to good causes. The first recorded evidence of a lottery is a keno slip from the Chinese Han dynasty (205–187 BC).

Lottery is a popular form of gambling that offers people the chance to win big sums of money. However, winning the lottery is a long shot and many who win wind up worse off than they were before. Nevertheless, people continue to buy tickets because they believe that it is their civic duty to support the state by putting a little bit of money in a lottery.

A common feature of lotteries is that the total prize pool is predetermined, and the cost of organizing and promoting the contest must be deducted from the pool. The remainder is available to the winners, with a preference in some cultures for a few large prizes rather than a great number of smaller ones.

The purchase of lottery tickets cannot be accounted for by decision models based on expected value maximization. Instead, these purchases can be explained by risk-seeking behavior. In particular, if the entertainment value of winning the lottery is high enough, the disutility of a monetary loss may be outweighed by the utility of non-monetary gains.