A casino is a gambling establishment. It may also refer to:

The precise origin of casino gambling is unknown, with primitive forms such as carved six-sided dice found in the oldest archaeological sites. Modern casinos offer a variety of games of chance and often combine these with restaurants, hotels, retail shops and other entertainment attractions. The most famous casino in the world is in Las Vegas, although there are several in Europe and Asia. In the US, most states have legalized casino gambling, although some have strict regulations regarding their location and size.

Casinos earn the most money from slot machines, which are among the least skill-dependent of all games. The player simply puts in a coin or paper ticket with a barcode and pulls a handle or pushes a button; then a series of reels spins, stopping at predetermined patterns. When the right pattern appears, the player wins a preset amount of money.

In the 1960s, organized crime figures in Reno and Las Vegas began investing their mob money in casinos. But legitimate businessmen were hesitant to invest in casinos, which had the taint of being mafia fronts. Federal crackdowns at even the hint of Mafia involvement meant that casinos had to keep their distance from gangsters.

Today, casinos are large, luxurious complexes that feature restaurants, hotel rooms and non-gambling game rooms for families. They offer a vast array of gambling activities, with the most popular being blackjack, craps and roulette. Casinos have advanced security measures, with video surveillance systems and other electronic safeguards. Some have catwalks in the ceiling above the gaming floor, which allow surveillance personnel to look directly down on players at table games and slot machines through one-way glass.