A casino is a building or large room in which people gamble. It also includes the equipment and staff necessary for gambling. The gambling is done either on table games, such as blackjack and poker, or on slot machines, such as those found in Las Vegas casinos. The atmosphere is loud and exciting, with players shouting encouragement to one another or to the croupiers (dealers). Often, there are live performers in casinos, such as musicians or dancers. Alcoholic drinks are served freely to gamblers and waiters rove the floor, offering them food and drink.

While the precise origins of casino gambling are obscure, it is known that it has occurred in many societies throughout history. Some cultures have even developed their own specific games of chance, such as the Chinese game of baccarat or the Indian card game rummy.

The modern casino began to appear in the 19th century, as European countries liberalized their gambling laws. The first reputable establishment was the Casino de Monte-Carlo, which opened in 1863. Casinos are most commonly located in cities or resorts, and they tend to be large, lavishly decorated buildings with multiple gaming tables and slot machines.

Casinos use a variety of psychological tricks to lure gamblers in and keep them gambling as long as possible. They invest millions in determining what colors, sounds, and scents will appeal most to customers. Casinos are also known for their high-end restaurants and luxury accommodations.