A casino is an establishment where people can gamble and win money. It is often combined with hotels, restaurants, retail shops and other entertainment facilities.

Most casino games have a significant element of chance, although some have a skill element. The mathematically determined advantage of the house over the players is known as the house edge (or expected value, in the case of poker). In table games with an actual croupier, the house earns its profit by taking a commission from each bet, called the rake. In other games, such as video poker, the house earns its profits by taking a percentage of the total bets placed.

In addition to securing the safety of their patrons, casinos use sophisticated technology to supervise their gambling operations. Slot machines are wired to electronic systems that monitor the exact amount wagered minute-by-minute and warn operators if any statistical deviations occur; roulette wheels are electronically monitored regularly for any statistical anomalies; and card counters employ high-tech tools to spot and detect cheating.

Because every game gives the house a certain mathematical expectancy of winning, it is very rare for a casino to lose money on its games. The virtual guarantee of gross profit motivates casinos to offer big bettors extravagant inducements, such as free spectacular entertainment, limousine transportation and luxury hotel rooms. This is in addition to the perks offered to lesser bettors, such as reduced-fare transportation and free drinks and cigarettes while gambling.