A casino is a gambling establishment that offers patrons a variety of games of chance and skill. Casinos can be found worldwide and operate on a wide range of scales, from large resort casinos to small card rooms. Casinos also exist on Native American reservations, which are exempt from state antigambling laws, and on riverboats and at racetracks (as racinos). In addition to traditional games such as blackjack, baccarat, and roulette, many casinos offer a variety of poker variants, including Texas hold’em and Caribbean stud.

Patrons play against the house, winning or losing money depending on the game and their skills. In some games, such as blackjack, the house edge is calculated by comparing optimal and non-optimal strategies. In other games, such as baccarat, the house edge is determined by the rules of the game and the number of decks used. Casinos earn a profit by taking a percentage of the money bet, charging an hourly fee for poker tables, or by collecting a fixed amount from each hand of slot machines.

In the twentieth century, casinos expanded rapidly in Europe and America. In the United States, the first major growth came from the introduction of Atlantic City casinos in 1978. Since then, casinos have opened on Indian reservations and in various cities, and they are becoming increasingly common at horse races and other gaming venues, as well as online. The typical casino gambler in 2005 was a forty-six-year-old female with above average income, according to a study by Roper Reports and the U.S. Gaming Panel by TNS. Casinos are willing to invest heavily in high-stakes gamblers, offering them free spectacular entertainment, luxurious living quarters, and reduced-fare transportation and hotel fees.