A lottery is a form of gambling in which numbers are drawn at random for a prize. Some governments outlaw lotteries, while others endorse them and organize state or national lotteries.

Most lottery games require a pool of tickets or other symbols on which bettors may write their names and/or numbers; these are then drawn and the winners are declared. A prize may be a fixed cash amount or goods. Costs of running the lottery and a percentage of the total pool go to profits or taxes for the organizer, while the rest is available for prizes. In some lotteries, the prize is a lump sum (cash or goods), while in others it is an annuity (regular payments over time).

Lottery revenues typically expand dramatically after they begin and then level off or even decline. To maintain or increase revenues, lottery organizers must constantly introduce new games to attract players.

In addition to the obvious problem of promoting gambling, there is the question of whether it is a proper function of government to run a lottery. Its promotion of instant riches in an age of inequality and limited social mobility is particularly disturbing, especially given that it disproportionately appeals to the poor.

Another issue with lotteries is that they are regressive in their distribution of winners. In the US, for example, most winners who choose a lump sum option receive a much smaller sum than the advertised jackpot because of income taxes.