A casino is a place where gambling is legal. It is often connected to a hotel or resort, and it may also be a separate entertainment venue. The most well known casinos are in Las Vegas, Monaco, and Macau, but they exist worldwide. Some casinos specialize in specific types of gambling, such as poker or blackjack, while others offer a wide range of games. Many casinos also have restaurants and bars.

A player can win money by playing casino games, and the amount of winnings is dependent on both the rules of the game and the probability of winning. The house has an advantage in most casino games, even those with some element of skill, because of the mathematics of chance. This advantage, which is mathematically determined (and often hidden from the players), is known as the house edge. In games where players compete against the house, such as poker, the casino earns money through a commission called the rake.

Casinos are a popular form of entertainment, and some are highly luxurious. Some have special catwalks on the ceiling, where surveillance personnel can look down through one-way glass directly at gamblers at the tables and slots. This feature is particularly useful when the casino is large, and it helps prevent cheating or theft. Despite their popularity, casinos can be dangerous places for both patrons and staff. Due to the high amounts of cash that are handled within them, both robbery and corruption are common problems in casinos.