A casino, also known as a gambling house or a gaming establishment, is a building that houses one or more games of chance. Gambling is a popular pastime in many societies and casinos are designed to facilitate gambling. Most countries have legalized casinos, but some still prohibit them. Casinos are often combined with hotels and restaurants.

Something about the nature of casinos encourages cheating and stealing, either in collusion or independently, which is why most have extensive security measures. Surveillance cameras are placed throughout the casino and computerized systems monitor the exact amount of money wagered minute-by-minute so that any deviation from expected results is quickly spotted. Roulette wheels are electronically monitored regularly to discover any statistical deviation from their expected results, and the cards in table games such as poker or blackjack are dealt using specific routines that follow certain patterns.

In addition, comps are given to regular players who spend a lot of time at the tables or playing slot machines. These can be hotel rooms, meals or show tickets. For extremely lucky or good players, casinos may even give out airline tickets or limo service.

Casinos are an essential part of the entertainment industry, and they are very popular. The modern casino is like an indoor amusement park for adults, and slot machines, black jack, roulette, craps, keno and other games contribute to the billions in profit that American casinos rake in every year. Casinos are also found on some American Indian reservations, which are exempt from state antigambling laws.