A casino is a facility for certain types of gambling. In most countries, it is legal to gamble in casinos; however, laws vary from country to country. Casinos are heavily regulated and have high levels of security. Most have entertainment facilities, such as restaurants and bars. A few also have hotels and other amenities.

Historically, the term casino referred to a public hall for music and dancing. In the second half of the 19th century, it became a term for an establishment that offered gaming or gambling. Today, casinos are a form of commercial entertainment and offer many different types of games. Some games require skill, while others are pure chance. Regardless of the game, the casino has a mathematical advantage over patrons, known as the house edge.

In order to reduce the house edge, casinos monitor player behavior. They use a variety of techniques to detect cheating and other irregularities. For example, dealers watch players closely for a suspicious pattern of movements or reactions to determine whether the player is palming cards or marking dice. They also note betting patterns on table games to prevent a patron from stealing money from other players.

Casinos reward good players with free goods and services. Comps may include free food, drinks and hotel rooms for large bettors; reduced-fare transportation, tickets to shows or even airline tickets for smaller bettors. The casino industry is also experimenting with technology to enhance security and accuracy. For example, roulette wheels are electronically monitored minute by minute, and chip tracking systems reveal anomalies in bets immediately.