Casinos have elaborate surveillance systems in place to monitor all aspects of the casino. Video cameras are installed at every table, window, and doorway, and can be positioned to focus on suspicious patrons. The video feeds are recorded for later review. Slot machines are also monitored, but no one is watching them. Computer chips inside them determine the payouts.

Some casinos even have catwalks built into the ceiling above the casino floor to allow surveillance personnel to monitor the floor directly. These catwalks are often fitted with one-way glass, allowing surveillance personnel to view the floor without being detected. These methods are effective in keeping the casino safe from theft and other criminal activity. While not always perfect, casinos with security systems are much more likely to be successful in preventing crimes.

The United States has over a thousand casinos, and this number is growing as more states look to legalize them. Currently, forty states have some form of casino gambling. This increase has been fueled in part by the Native American gaming industry. Casinos are not confined to the larger cities; the Las Vegas Valley alone has over 1,000 casinos. In terms of revenue, the Chicago metropolitan area and Atlantic City, New Jersey rank second and third, respectively.

Casinos offer a wide variety of games of chance. While most casino games offer a predictable long-term advantage for the casino, there are also games with a skill element. Players who are skilled enough can overcome this long-term disadvantage and win the game. These players are known as advantage players.