A casino is a gambling establishment where customers gamble by playing games of chance or, in some cases, skill. Most casinos offer a wide range of gaming options such as roulette, blackjack, poker and slot machines. In addition, many casinos feature a variety of entertainment options such as live music and shows. In the United States, there are more than 1,000 commercial casinos and hundreds of tribal casinos. Many of them host daily and weekly poker games and events as well as the World Series of Poker.

Security in a casino starts on the casino floor, where employees watch patrons to make sure that everything goes as it should. Dealers are heavily focused on their own game and can easily spot blatant cheating techniques like palming, marking or switching cards or dice. Pit bosses and table managers have a wider view, watching for betting patterns that might indicate cheating or other irregularities. Elaborate surveillance systems include cameras in the ceiling that allow security personnel to watch every table, window and doorway at once.

Because each casino game has a mathematical expectancy of winning, it is very rare for a casino to lose money on its games in one day. This virtual assurance of gross profit enables casinos to offer big bettors extravagant inducements like free spectacular entertainment, limousine transportation and elegant living quarters. Even lesser bettors are offered reduced-fare transportation, hotel rooms and free drinks or cigarettes while they play.