A casino is a gambling establishment that offers various kinds of games of chance and in some cases skill. It takes a fee from gamblers in the form of a rake, or a percentage of their winnings, called a payout. A casino is often a standalone building or part of a resort, hotel, or entertainment complex. It is also found on some American Indian reservations, where state antigambling laws do not apply.

Some casinos, especially those in Las Vegas, are renowned for their glitz, glamour, and spectacle. Others are more low-key, with a focus on service and comfort. Still, they all offer a wide variety of betting options for patrons.

Casinos can be classified into three general categories: gaming machines, table games, and random number games. Gaming machines, such as slots and pachinko, are played by one player at a time and do not require the involvement of casino employees. Table games, such as blackjack and craps, involve a dealer and several players competing against the house (the casino). Random number games are based on the selection of random numbers, either from a slot machine or another source.

Because of the large amounts of money handled, casinos are vulnerable to fraud and theft by both patrons and staff. To prevent this, they employ a number of security measures. Some of these include the use of security cameras and manned surveillance rooms. Others rely on more sophisticated technology, such as chip tracking systems that record wagers minute-by-minute and warn of any anomaly; roulette wheels are electronically monitored to discover quickly any deviation from their expected results.