A casino, also known as a gambling establishment or a gaming room is a place where people gamble by playing games of chance. Gambling is legal in many places, and casinos are regulated by law to ensure honesty and fairness. Many casinos offer a variety of gambling games, including blackjack, roulette, and video poker. Some casinos specialize in high-limit games. Others provide entertainment, dining, and accommodations in luxury facilities.

Casinos are designed to generate a profit from the wagers of patrons on games that rely mainly on luck, though some require skill. They may generate profits by taking a percentage of total bets, or a flat fee per game played. The profit margin varies depending on the type of game and the size of the bets, and is known as the house edge. Casinos also earn revenue from beverage sales, complimentary items (such as drinks and cigarettes), and from the rent of space to outside events such as concerts and shows.

Due to the large amounts of money handled, security is a major concern for casinos. Most employ a variety of electronic surveillance and physical measures to prevent cheating and theft, both by players and employees. For instance, many casinos have catwalks over the gaming floor that allow surveillance personnel to look directly down on the table and slot machines through one-way glass. Some have cameras in the ceiling that monitor activity throughout the building. Additionally, some casinos have a full-time staff of detectives and investigators to respond to claims of illegal activities.