A slot machine is a casino gambling machine with three or more reels which spin when a button is pushed. Slot machines include a currency detector that validates the money inserted to play. The machine pays off according to patterns of symbols visible on the front of the machine when it stops. Slot machines are the most popular gambling method in casinos.
A person playing a slot machine can insert cash, or in ticket-in, ticket-out machines, a paper ticket with a barcode, into a designated slot on the machine. The machine is then activated by means of a lever or button, or on newer machines, by pressing a touchscreen on its face. The game itself may or may not involve skill on the player's part — or it may create the illusion of involving skill while only being a game of chance.
The object of the game is to win money from the machine. The game usually involves matching symbols, either on mechanical reels that spin and stop to reveal one or several symbols, or on simulated reels shown on a video screen. The symbols are usually brightly colored and easily recognizable, such as images of fruits, numerals or letters, and simple shapes such as bells, diamonds, or hearts; newer video slot machines use animated cartoon characters and images of popular actors or singers.
Most games have a variety of winning combination of symbols, often posted on the face of the machine (or available on a different screen, accessible by touching a button on the main touchscreen, on video slot machines). If a player matches a combination according to the rules of the game, the slot machine credits the player cash or some other sort of value, such as free spins or extra games. Free spins are a common feature in modern slot games allowing the user to spin the machine's reels without charge.Information taken from Wikipedia. CC BY-SA 3.0.