A casino is a gambling establishment where patrons may play games of chance for money. Some casinos offer a wide variety of games while others specialize in certain types. Some are located in Las Vegas or Atlantic City, and other casinos operate nationwide and internationally. Most of these casinos are staffed by people who make the players feel welcome and provide them with many perks, including free food and drinks. These perks are known as comps. Some of these include airfare, hotel rooms, show tickets and other forms of entertainment.

Gambling in various forms has been present in most societies throughout history, but until the late 20th century it was not legal in most places. The first casinos began to appear in Nevada, and other states grew quickly after their residents realized how much tourism they generated from these gambling facilities.

Something about the gambling atmosphere seems to encourage cheating and stealing, either in collusion between patrons or by individual patrons, especially when large sums of money are involved. To counter this, casinos spend a considerable amount of time and money on security. Many have cameras throughout the facility, and employees watch over tables with a closer eye, looking for suspicious betting patterns or signs of palming and marking cards.

Because of their virtual assurance of gross profit, casinos invest heavily in big bettors and give them extravagant inducements such as elegant living quarters and free spectacular shows. In addition, they may offer them reduced-fare transportation and hotel room accommodations (known as comps). These perks are designed to encourage gamblers to spend more time and money in the casino.