A casino (also called a gambling hall or a cassino) is a place where people play games of chance for money or other rewards. The precise origins of gambling are obscure, but it is believed that people have gambled in some form throughout history. Modern casinos vary in size and design, but they generally offer a wide variety of gambling games and are open to the public. Casinos are regulated by law and have various security measures in place to prevent cheating and other violations of state or local antigambling laws.

Most casino games are based on chance and the result of each bet is determined by luck alone. In some games, however, players can affect the outcome of the game through strategy or skill. Examples of casino games that involve a degree of skill include blackjack, poker, and roulette. In most casinos, winning bets are paid out in cash, while losing bets are forfeited.

Casinos have a tendency to attract high-stakes players who spend more than the average patron. These high rollers are often given special treatment by the casino staff and may be rewarded with free suites and other amenities. In the twentieth century, casinos increasingly devoted more space and resources to their highest-stakes players.

Most modern casinos use extensive technology to monitor and supervise the games themselves. For example, slot machines have built-in microcircuitry that can record the exact amount wagered on each spin; table games are monitored electronically to ensure that all bets are placed properly and to warn croupiers of any suspicious activity; and roulette wheels are inspected regularly for statistical deviations.