A casino is an establishment for gambling. These facilities usually combine gambling with hotels, restaurants, retail stores, and other tourist attractions. Some casinos also host live entertainment events such as stand-up comedy, music concerts, and sports games. The precise origin of gambling is unknown, but it is believed that gambling has existed in almost every society throughout history. The modern casino is often an elaborately decorated, opulent building that features several types of gambling activities. The casino industry has become very large and is regulated by laws in many countries.

Modern casinos use sophisticated technology to oversee their operations and protect their profits. For example, some casinos use catwalks that allow security personnel to look directly down through one-way glass on table and slot activities. In addition, specialized chips with built-in microcircuitry interact with electronic systems in tables to enable the casino to monitor the exact amounts wagered minute-by-minute and to detect any anomaly; roulette wheels are electronically monitored regularly to discover any statistical deviation from expected results. Casinos have also dramatically increased their use of video cameras to supervise the games themselves.

While the exact number of people who gamble in casinos is not known, it is estimated that between five and 25 percent of those who visit casinos are addicted to gambling. These individuals generate a significant portion of casino profits, and they divert spending from other forms of entertainment. As a result, many economic studies have shown that casinos actually bring negative net benefits to their communities.