A casino is a facility where people can gamble by playing games of chance for money or other items of value. The exact origin of gambling is unknown, but it is believed to have been around for millennia. Evidence of gambling has been found in China (2300 BC), Rome (500 AD) and even Ancient Egypt. In modern casinos, customers gamble using chips that represent cash, and the house usually earns a commission on winnings called the rake. A casino may also give away complimentary items to players, known as comps.

In games of pure chance, the house has a mathematical advantage over players, and this is known as the house edge or vigorish. However, some casino games have a skill element, and players with sufficient skills can eliminate the house edge, earning a short-term profit that can be large. These players are known as advantage players.

The term casino has come to refer to a specific building or room where gambling takes place, but it originally referred to a collection of gaming rooms. The best known casino is the Monte Carlo in Monaco, which opened in 1863 and is still a major source of income for the principality. The elegant spa town of Baden-Baden in Germany, which first became a playground for nineteenth century aristocrats, is another famous casino.

Casinos are most often built in or near resorts and tourist destinations, and attract visitors from all over the world. They offer a variety of entertainment options for their guests, including concerts and other shows. Modern casinos usually employ a combination of physical security forces and specialized surveillance departments to monitor the activity of their guests and employees.