A casino is a place where people gamble by playing games of chance, in some cases with a small element of skill. It is also a place of entertainment, and many casinos have restaurants, bars, and live music. Some have a reputation for being glamorous or decadent. Casinos are usually heavily guarded to prevent cheating, stealing, and other crimes. In addition to the usual security measures, some casinos use elaborate surveillance systems that have cameras in every room and even on the ceiling, and can be adjusted to focus on suspicious patrons.

Something about the large amounts of money handled by casinos attracts both crooks and people with compulsive gambling habits. Both are tempted to steal and cheat, either in collusion with other patrons or independently; that is why casinos have so many security measures. Casinos also pay attention to customer service, offering perks such as free show tickets and rooms for gamblers who spend enough money.

In the past, mobster money flowed steadily into Reno and Las Vegas, but legitimate businessmen were reluctant to invest in a casino because of its seamy image. Mobster leaders, however, had plenty of cash from their drug dealing and extortion rackets, and often took sole or partial ownership of casinos. Casinos are a major source of revenue in Nevada, and they are spreading throughout the country. They are especially popular in New Jersey, Atlantic City, and Chicago. However, economic studies have shown that casinos have a net negative effect on local economies because they take money away from other forms of entertainment and hurt property values.