A casino is an establishment for gambling. Casinos often include a mixture of games of chance and skill, as well as restaurants, bars and other entertainment venues. They are usually designed in a lavish and eye-catching way to attract customers and encourage them to gamble and spend money. Some casinos are also known for certain unconventional structural features, such as catwalks in the ceiling which allow surveillance personnel to look down, through one-way glass, on the activities of table players and slot machines.
Gambling has been a part of human culture for millennia. Evidence of dice-based gambling dates back to 2300 BC China, while card games like blackjack have been around since the 1400s. In modern times, casino games have become increasingly sophisticated. During the 1990s, many began to incorporate electronic elements in their operations, such as chips with built-in microcircuitry that allow casinos to monitor the exact amounts placed minute by minute, and detect any anomalies; and roulette wheels are now routinely monitored electronically for statistical deviations from their expected results.
There are more than 1,000 casinos in operation worldwide. Many of them are large and have multiple floors, but a significant number are smaller and located in more modest settings. Some are also based on Native American reservations, which are not subject to state anti-gambling laws. In the United States, Las Vegas is by far the largest casino center, followed by Atlantic City and Chicago. In addition to the traditional gaming rooms, many casinos have extensive selections of slot and video poker machines.