A casino is a facility where people can play games of chance for money or other rewards. It may also include entertainment, restaurants, and hotels. In some places, casinos are regulated by law. Some casinos are built in lavish hotel-casino complexes and have fountains, towers, or replicas of famous landmarks. People can gamble on table games such as blackjack, roulette, and poker, or on slot machines. Most casino games have an element of skill, and the house usually has a mathematical advantage over the players. The house edge can be very small, but over time it can make the casino enough money to build elaborate structures and offer comps (free items) to certain patrons.

Some casinos, especially those with a high concentration of tables, focus on high rollers, or players who spend large amounts of money. These patrons get free rooms and other luxury amenities, as well as special treatment from the staff. In the twentieth century, casinos expanded their gambling facilities to include a variety of electronic and video games.

Security is a major concern at casino facilities, due to the large amount of money handled by both employees and patrons. Many casinos use cameras to monitor their patrons and prevent cheating or stealing. Other measures include requiring players to keep their cards visible at all times, avoiding playing near other people, and requiring croupiers to watch for suspicious betting patterns. Despite these measures, some casinos have been subject to theft and fraud by patrons and workers, either in collusion or independently.