A public room or building where the playing of gambling games (including roulette, baccarat, blackjack, poker, and slot machines) is the principal activity. Now often also used for a large hotel or similar establishment featuring one or more such rooms as its primary attraction. Historically, a casino was a place where criminals met to gamble and organize illegal rackets. Mafia money poured into Reno and Las Vegas casinos in the 1950s, giving them a reputation as seedy and dangerous that remains today.

While musical shows, lighted fountains, and shopping centers help attract customers, casinos wouldn’t exist without games of chance. The billions in profits raked in each year by casinos come from the built-in statistical advantage that they have over the people who bet there.

To mitigate these disadvantages, casinos employ a variety of security measures. These range from surveillance cameras, which allow the security staff to monitor a wide area of the casino, to sophisticated electronic systems that oversee individual betting chips’ microcircuitry and identify any suspicious patterns in wagering; meanwhile, roulette wheels are regularly monitored electronically to discover any statistical deviations.

Casinos may also reward their biggest spenders with free hotel rooms, meals, show tickets, or even limo service and airline tickets. These are called comps and are based on the amount of time and money that a person spends at a particular casino, as well as the type of game played and its stakes. The mathematical analysis of casino games and their expected outcomes is a subfield of computer science and statistics known as gaming mathematicians or gambling analysts.