A casino is a building or room where gambling games are played. Modern casinos are often combined with hotels, resorts, restaurants, retail shops and other tourist attractions. They may also feature bars, swimming pools, spas and other entertainment options. Casinos can be located in cities, resorts and private islands. Some countries have legalized them while others ban or restrict them. They are usually staffed by trained security personnel and are monitored by cameras. In the United States, the Las Vegas Valley has the largest concentration of casinos. Other major gambling centers include Atlantic City, New Jersey and Chicago.
Most casinos offer a variety of games that use chance or skill. Some casinos specialize in specific games, such as poker and blackjack. Others focus on games with a high house edge, such as roulette and craps. The house edge is the mathematically determined advantage of the casino over players, which can be as low as two percent. The advantage can be earned through table minimums and bets, or paid out in comps to patrons.
Due to the large amount of money that is handled within a casino, both patrons and employees may be tempted to cheat or steal, either in collusion or independently. To combat this, most casinos have extensive security measures. These may include the use of cameras and other electronic surveillance systems, physical barriers to entry and exit, and staff members who patrol the casino floor for suspicious behavior.