A casino is a place where people can play gambling games, especially roulette, blackjack and poker. Some casinos also offer a variety of entertainment options like live music and shows. There are a number of laws regulating the operation of casinos in most countries. The legal age to gamble in a casino varies by state, and most require players to be at least 21 years old.
Security in a casino starts on the floor, where employees keep an eye out for blatant cheating like palming or marking cards. They also look for betting patterns that might indicate cheating. Each casino table has a pit boss or other higher-up watching it closely, noting how much money is coming in and out. This information is used to calculate the house edge and variance for each game, which helps management decide how much cash to hold in reserve. These people are called gaming mathematicians and analysts.
In addition to the obvious security measures, casinos use technology to monitor their own games as well. For example, some tables have chips with built-in microcircuitry that allows the casinos to see how much is being wagered minute by minute and warn them of any statistical deviation from expected results; roulette wheels are electronically monitored regularly to discover any suspicious tilting.
Other, more elaborate security features include catwalks in the ceiling that allow surveillance personnel to look down, through one way glass, on the tables and slot machines from a separate room filled with banks of security monitors. And, of course, casinos use the ubiquitous video cameras to watch everything that happens on the floor and around the building.