A casino is a gambling establishment that offers a variety of games to patrons who are willing to wager money or other items of value. It may also offer services such as restaurant dining, luxury hotel rooms, and entertainment. Casinos are most commonly located in cities with large populations of people who enjoy gambling. In the United States, there are several cities and towns that are well known for their casinos, including Las Vegas and Atlantic City.

The main area of a casino is the gaming floor, where the majority of gambling activities take place. These can include traditional slot machines, table games such as blackjack and roulette, and poker, which is often played against other players for a fee (known as the rake).

Gambling probably predates recorded history, with primitive protodice (cut knuckle bones) and carved six-sided dice found at ancient archaeological sites. The modern casino evolved during the sixteenth century, with a gambling craze that swept Europe at the time. Italian aristocrats would hold private parties at places called ridotti, where they could gamble legally without fear of prosecution.

Security in casinos is a major concern, especially given the amount of money that passes through the buildings on a daily basis. Casinos use a variety of methods to deter criminal activity, both through technological means such as cameras and other surveillance systems, and through enforcement of rules and standards for behavior. Nevertheless, crimes committed in casinos are rare.