A casino is a building or room where people can play gambling games. It is also a place where people can meet friends and socialize. Casinos are most often found in cities with large populations, such as Las Vegas, Nevada, and Atlantic City, New Jersey. Some casinos are operated by government-licensed organizations, while others are owned and operated by private individuals. Many casinos are known for their luxurious facilities, including top-rated hotels and spas.

Gambling in some form has been a part of human civilization for millennia. Evidence of dice-based gambling dates back to 2300 BC in China, and card games appeared around 500 AD. Modern casinos, however, are generally based on gaming machines and random number generators (RNGs). In addition to traditional casino games, some offer food and beverage services.

The casino industry is regulated in most jurisdictions, with the legal framework varying widely across countries and jurisdictions. The most common regulation is the licensing of the casino establishment by the local authority. This usually requires a detailed report of the operation to be submitted to the authorities. It also requires a high level of security, with cameras located throughout the premises and staff trained to spot cheating and theft.

Most casino games have mathematically determined odds that guarantee the house a constant net profit over players. These are known as the house edge and variance, and they are calculated by mathematicians specializing in gaming analysis. These figures are used to determine how much a player is likely to lose on any given game and how much the casino needs in reserve cash.