A casino is a gambling establishment where patrons gamble by playing games of chance. These include slot machines, roulette, baccarat, blackjack, craps, and video poker. Most games have mathematically determined odds that ensure that the house has an advantage over the players. The house edge can vary depending on the game and the number of bets made. The casinos profit from the game by charging a fee for admission or giving complimentary items to high-spending players (known as comps).

While gambling predates recorded history, the modern casino did not develop until the 16th century, during a time of great prosperity for European merchants and bankers. The first centralized casino complexes were built during this period, particularly in France and the United Kingdom. Casinos are licensed and regulated in most countries. In the United States, they are often located on Indian reservations and are not subject to state antigambling laws.

Many casinos have added attractions to draw in customers other than gambling, such as restaurants, bars, and entertainment venues. These facilities can be large and spectacular or small and intimate, depending on the town and its needs.

Modern casinos employ a variety of security measures to prevent cheating and theft by both guests and employees. These range from well-trained personnel to sophisticated technology. For example, electronic chips allow casinos to monitor bets minute by minute and alert them to any abnormalities. The chips are connected to a computer that keeps a record of all bets placed. A specialized surveillance department also constantly monitors the action in the gaming areas, detecting any suspicious activity.