A casino, also known as a gambling hall or gaming house, is a place where various forms of gambling are carried out. The term is most often applied to a large building that houses multiple gambling activities, but it can also refer to a room or space set aside for such purposes. The concept of a casino is closely related to that of a public house and it may contain restaurants, bars and stage shows as well as gambling tables and machines.

Gambling probably predates written history, with primitive protodice (cut knuckle bones) and carved six-sided dice among the oldest archaeological finds. A casino as a place where a variety of different gambling activities are under one roof did not develop until the 16th century, when a casino craze swept Europe. Italian aristocrats, for example, would hold private parties in places called ridotti, where they could gamble, drink and socialize, even though gambling was technically illegal.

Modern casinos use a variety of security measures to keep the patrons safe from cheaters and thieves. Some of the most effective methods involve cameras and high-tech surveillance systems. These cameras are positioned throughout the facility, and they can be directed by workers in a room filled with banks of security monitors. Some casinos also have catwalks in the ceiling that allow security personnel to look down, through one-way glass, at activities on the casino floor.

Many casino employees are trained to spot blatant cheating, such as palming or marking cards, and they are also skilled at observing betting patterns that might indicate collusion. In addition, the house edge and variance of each game are analyzed by mathematicians and computer programmers employed by the casino to make sure it is making a reasonable profit.