A casino (also known as a gaming house or a gambling establishment) is an establishment where people can gamble. Casinos are often combined with hotels, restaurants, retail shops, and other tourist attractions. In the United States, casinos are usually licensed and regulated by state governments.

The precise origins of gambling are not well known, but it is generally believed that some form of it has been in existence for thousands of years. Gambling is most commonly associated with dice, card games, roulette and other table games, but it can also be found in lotteries, horse races and even video poker machines.

Casinos make money by charging a commission, or “vig,” on the bets placed by patrons. This may be a flat percentage of the total amount wagered, or it may vary by game. For example, a casino might reduce the advantage on roulette to attract small bettors, while keeping it high on craps to draw big bettors. Slot and video poker machines are the economic backbone of American casinos, earning revenue from their high volume of play at low costs.

In the early 1990s, casinos greatly increased their use of technology to supervise the games themselves as well as to monitor gambling behavior. For instance, betting chips with built-in microcircuitry enable the casino to keep track of each bet minute by minute and alert players to any anomaly; roulette wheels are electronically monitored regularly to discover statistical deviations from their expected results.