A casino (from French, literally “a gambling house”) is an establishment for certain types of gambling. Casinos are usually located in or combined with hotels, restaurants, retail shops, and/or cruise ships. In the United States, casinos are regulated by state law and must be licensed. Some states prohibit the presence of non-licensed gambling houses, while others restrict the number of casinos. In some cases, a casino may be owned by an individual or group of individuals.

Something about the nature of gambling seems to encourage cheating and stealing, either in collusion or independently. This is why casinos spend a great deal of time and money on security. Elaborate surveillance systems monitor every table, change window and doorway; computers monitor the results of each game, revealing any statistical deviation; and betting chips have built-in microcircuitry that interacts with electronic systems in each table to reveal the amount wagered minute by minute. In addition, staff regularly audit the random-number generators that determine slot machine payouts.

But despite their elaborate themes and facilities, casinos would not exist without games of chance. Slot machines and table games such as blackjack, roulette, craps and baccarat provide the billions in profits that casinos rake in each year. This article looks at the history of casinos, their popularity in modern society, how they work, the best games to play and how they stay safe. It also considers the dark side of casinos — the billions in lost productivity and treatment costs resulting from problem gambling.