A lottery is a game of chance in which tickets are sold and prizes are drawn randomly. It is a form of gambling and of raising funds for public charitable purposes. It is also a common form of government policy, although state lotteries differ in their structure, rules, and administration.

Generally, the purchase of a ticket is a rational decision for an individual if the expected utility of monetary and non-monetary gain exceeds the disutility of the monetary loss. The entertainment value of the ticket (or other non-monetary gains) and the potential for a substantial jackpot prize are often important factors in this analysis.

The first recorded public lottery to distribute tickets for a cash prize took place in the Low Countries during the 15th century to raise funds for town fortifications and to help the poor. It is believed that lottery games may have much longer roots, however. A lottery was held during the Roman Empire to raise money for repairs in the City of Rome, and some scholars have argued that casting lots to decide fates and possessions has long been a part of human society.

The basic elements of a lottery are that bettors write down their names and the amount staked on the ticket, which is then deposited with the lottery organization for subsequent shuffling and selection in a drawing. A bettor may also buy a numbered receipt in order to verify later whether his ticket is among the winners. Lotteries typically offer the option of a lump sum payout or an annuity.