A casino is a place where people can play gambling games. The games usually give a long-term advantage to the house or “house”, but players can win money in the short term, too. Some casinos also offer skill-based games, which require a certain amount of knowledge. Players who possess sufficient skills can eliminate the house edge and maximize their profits. Such players are known as advantage players.

Gaming machines are the principal source of income for casinos. The games are controlled by computers and are operated by employees, called croupiers or dealers. Some games have a random number generator (RNG), which produces random numbers for each spin. Other games use a physical dice or shuffled cards.

The modern casino relies on technology for security as well. For example, chip tracking systems enable casinos to monitor the exact amounts of betting chips minute-by-minute; roulette wheels are electronically monitored regularly so that any statistical deviation can be detected quickly. Video cameras are used for general surveillance as well as to observe betting patterns.

Most of the world’s casinos are located in large cities. The largest concentration is in Las Vegas, followed by Atlantic City and Chicago. Some casinos are located on Native American reservations and are exempt from state antigambling laws. A smaller number are located in rural areas. These generally have fewer amenities than larger casinos, but may have lower minimum bets and higher payback percentages. This makes them popular with locals, especially for low-risk bets.