Having appeared in the end of the 19 century slot machines very quickly gained the global popularity. A slot is a gaming device that has three or even more reels which start spinning after a lever but today button is pressed. The machines give out payouts basing on combinations of symbols which appear on the reels after they stop. At the point slot games are the most popular activity and make the lion’s share of the casino income.

The first slot machine was built by Charles Fey in 1887. It was the machine with mechanical reels, and there is only one left now and displayed in Reno. It was a machine which had 3 reels and a total of five symbols – spades, hearts, diamonds, horseshoes. There was also a Liberty Bell that gave the slot its name as well. Fey invented an efficacious automatic payout mechanism.

Soon after that Sittman and Pitt from New York developed a gambling device, a forerunner of the modern slot machines. There were 5 drums that had 50 card faces because it was based on poker. That machine was extremely popular and soon many bars in the city had one or more slot machines. But that time the payout often was a free cigars, a can of beer or drinks.

In the beginning of 1960s, the first entirely electro-mechanical slot machine was developed. That machine was known as Money Honey. In 1996 WMS Industries developed the first video slot “Reel ‘em In” which offered a second-screen bonus round.

Nowadays a player can find a great number of slots on the Web. There are slot machines to every taste from classic, three reel slots to progressive video slots. To attract more players online casinos often offer various promotions and online slot tournaments.

Modern slots are controlled by erasable programmable read-only memory computer chips. New slots have cutting-edge anti-counterfeiting and anti-cheating devices which are very difficult to cheat. All slots are controlled by the Random Number Generator that guarantees that symbols appear on reels randomly. After having pushed the Spin button the computer rotates the reels, stops and different symbols lay on the reels.

The majority of well-established and famous casinos offer their players an opportunity to play free of charge that is why they can first try a game before starting to play for real money.