Powerball is an American lottery game sold through U.S. lotteries as a shared jackpot pool game. It is coordinated by the Multi-State Lottery Association (MUSL), a non-profit association formed by an agreement with member lotteries. There are currently 31 members - 29 state members, the District of Columbia, and the United States Virgin Islands. (FloridaFact: date=October 2008 will join Powerball in January 2009; details listed below.) MUSL manages the finances for each game, develops new games, conducts the drawings and provides other services and other games to its member lotteries, including Hot Lotto, Wild Card 2 (smaller games played similar to Powerball), 2by2, and Cashola, (a progressive jackpot video lottery (slot) game).

Powerball was the first game to use two drums as its core game. Using two drums offers more flexibility in game design, allowing for the possibility of both high jackpot odds and low odds for other prize levels. The two-drum concept was suggested by Steve Caputo of the Oregon Lottery. The two-drum concept has since been copied by Mega Millions (formerly The Big Game) in the U.S., Australia's Powerball, Thunderball in the United Kingdom, and EuroMillions.

Powerball's predecessor game began in 19881 as Lotto*America; the game, and name, were officially changed to Powerball on April 19, 1992. (MUSL then consisted of 14 states and Washington, D.C.; Maine was a 16th member, but it left MUSL during the transition from L*A to Powerball; Maine would not offer the game until 2004.). The matrix has been changed periodically. On March 4, 2001, an optional multiplier wheel (called "PowerPlay") was added. On November 2, 1997, the annuity period was changed from 20 to 25 years, and the cash option was added. The annuity currently consists of 30 graduated payments (increasing annually) over a period of 29 years. Powerball is drawn Wednesdays and Saturdays near Des Moines, Iowa; the game's drawings will move permanently to Florida in 2009 with Powerball becoming available there.Fact: date=October 2008

The most recent successful claim for a nine-figure Powerball jackpot winner ($100 million or higher annuity value) was for a ticket purchased in New Mexico for the September 27, 2008 drawing. The nine people claiming the ticket (eight were part of married couples) won approximately $206.9 million (annuity value); the group chose the cash value of about $102.9 million.

Among notable nine-figure wins prior to this was on a ticket that was purchased in Richmond, Indiana; that community had also produced the then-U.S. record $295.7 million (annuity) winning ticket for Powerball (July 29, 1998.) The businesses in Richmond, Indiana (both of the Speedway convenience-store chain) that have provided two of the largest Powerball winners are situated about three miles (five kilometers) apart.