A casino is a gambling establishment offering various types of chance-based games. Most casinos have gaming tables and slot machines. Some casinos also offer sports betting and other forms of electronic gambling. Most casinos have a house edge, which gives the casino a long-term advantage over players. However, some games have skill elements, and players who possess sufficient knowledge can eliminate the house edge or at least reduce it to a reasonable level. These players are known as advantage players.

In modern times casinos have become increasingly technologically advanced. For example, some casinos use specialized chips with built-in microcircuitry that allows them to monitor the exact amounts wagered minute by minute; roulette wheels are electronically monitored to discover any statistical deviations from expected results; and some casinos employ computer programs (called gaming mathematicians) to calculate optimal strategies for various games.

Despite the proliferation of technology, casino gambling is still very popular, and is enjoyed by millions of people around the world. The casino is a cherished cultural icon, romanticized in film and literature with images of high-stakes gambling tables surrounded by a select group of guests dressed in tuxedos or evening gowns. Casinos are operated by many governments and private businesses, and are often regulated by government bodies. Some countries have legalized casinos, while others have prohibited them or restricted their operations. In the United States, casinos are licensed and regulated by state law. In addition, some American Indian reservations operate casinos, which are exempt from state antigambling laws.