A casino is an establishment that allows people to gamble and play games of chance. Casinos usually offer a variety of gambling activities, including table games such as blackjack and roulette, slot machines, poker rooms, and live entertainment. Many casinos also offer hotels, restaurants, retail shops, and cruise ships.

The precise origin of gambling is unknown, but it is generally believed that it has existed in some form throughout history. Evidence of early gambling has been found in Ancient Mesopotamia, Rome, Greece, and Elizabethan England. In modern times, the casino has become a major source of revenue for governments and private businesses.

There are some 3,000 legal casinos in the world, including those in Nevada, New Jersey, and Atlantic City. Several American Indian reservations have also opened casinos, as they are not subject to state antigambling laws.

Something about the casino environment seems to encourage patrons and employees to cheat or steal, either in collusion or independently. To combat this, most casinos spend a large amount of time and money on security. Casino security is normally divided between a physical force and a specialized surveillance department. The latter operates a closed circuit television system known as the eye in the sky, which can monitor every table, window, and doorway.

Unlike the more lavish casinos that now dot the Las Vegas strip, the original gambling houses were small and often cramped, although they did have a certain elegance. In the 16th century, when a gambling craze swept Europe, Italian aristocrats met in clubs called ridotti to enjoy themselves with card games, dice, and other gambling activities without fear of losing their fortunes.