A casino or gaming house is an establishment for certain types of gambling. Casinos are often built near or combined with hotels, restaurants, retail shops, and other tourist attractions. Some states have laws against casinos, while others regulate and license them. The precise origin of gambling is not known, but it is believed to have existed in many societies throughout history. Modern casinos generally allow players to exchange money for chips or other forms of payment and to place bets on various events in games of chance or skill.

Casinos typically offer an advantage over players that is mathematically determined and constant (or at least predictable). This advantage is known as the house edge or vig, and it is what allows casinos to make profits from the games played by customers. However, some casinos also offer games with an element of skill, such as poker, where the house does not have a fixed advantage and is instead subject to a varying percentage of the money bet by each player.

The most common casino games include gaming machines, table games, and random number games. Gaming machines, such as slot machines and pachinko, are played by one player at a time and do not require the assistance of casino employees. Table games, such as blackjack and craps, involve a face-to-face interaction between players and are conducted by dealers. Random number games are based on the selection of random numbers by a computerized generator.