A casino is a place where people pay to gamble. The games of chance have a built in advantage for the house that is called a “house edge.” Even though this edge may be small, it adds up over the millions of bets placed at casinos each year. As a result, the casinos make money and can afford to build lavish hotels with fountains, towers and replicas of famous landmarks.

In order to keep patrons from cheating or stealing, casinos have various security measures. The most obvious is the presence of security cameras throughout the property. Another is the use of “chip tracking” to monitor the movement of betting chips minute by minute; and the use of electronic monitoring systems on roulette wheels to detect any statistical deviation from their expected values.

Casinos are also staffed with highly trained security personnel who know the ins and outs of their specific gaming operations. This knowledge allows the staff to spot suspicious behavior more quickly and accurately. Casinos also employ a variety of other security methods, such as the use of a “hot button” to alert security in case of a problem; and the practice of using a card table to check a patron’s ID before allowing him or her to play a game.

Casinos can be found in many cities and countries around the world. In the United States, they are most prevalent in Las Vegas and Reno in Nevada; Atlantic City, New Jersey; and Chicago. Increasingly, they are being opened on Native American Indian reservations and in other states that have legalized gambling.