A casino is a building or room in which gambling games are played. Gambling has been a part of human society for millennia, with evidence of game-playing dating back to 2300 BC in China. Modern casinos, also called gambling halls or gaming rooms, feature a wide variety of games with fixed odds and variable payouts. Many have restaurants, bars, high-end retail shops and state-of-the-art theaters for entertaining shows.

Casinos earn money by taking a percentage of the wagers made on their machines or tables. This is known as the house edge or advantage, and it is the casino’s primary source of revenue. The exact edge varies from game to game; the advantage of some, such as blackjack, is less than that of others, including roulette and craps. The house edge can be reduced through skillful play, known as card counting or fundamental strategy.

Some casinos also offer other games, such as video poker and sports books. These generate income from bets placed on various events, such as football matches or horse races. Most casinos have security departments to prevent cheating and stealing by patrons or employees, in collusion or independently. These departments use surveillance equipment to monitor the premises.

Casinos are usually located in tourist destinations or in cities that are built around them. Las Vegas is famous for its casinos and attracts gamblers from all over the world. Monte Carlo, in Monaco, is another well-known casino. In recent years, casinos have opened on American Indian reservations in states that do not prohibit casino gambling.