 The firts slot machines were manufactured in San Francisco in 1894 by Charles Fey. The "Liberty Bell" slot machine inspired the moder American slot machines. It's basic design continues to be used in mechanical gaming devices today. Arround 1930 the slot machines started to be popular, in the 40's they started to be used in Las Vega's hotels.
They were ment to entertain wifes and girlfriends of the whealty guests, but thanks to the income they generated, in the 90's slots achived more popularity than table games.
There are two kind of slot machines: progressive (straight slots ) and flat tops. There is only one difference between the two kind of the game, they differ in the pay out: flat tops will pay the winner a predetermined amount, whereas progressive slots have a jackpot that grows by a percentage of each coin played.
Slots do not require player skills. The aim of the game is to spin the reels so that the symbols on all reels line up on the payline in a winning combination. When this is achieved the slot machine pays out according to the payoff table posted on its front.
The payoff table tells players what the winning combinations of symbols are for that machine and what each combination pays based on the number of coins put in for the spin. Players have a much greater chance of hitting any of the lower-paying combinations.
The most common machines have three reels, but casinos do offer machines with four or five.
Quarter and dollar machines are the most popular though nickel machines do exist and can be found in some casinos, just as some casinos have VIP rooms with $5, $25 and $100 machines.
There are, furthermore, slot machines which accept more than one coin at a time and pay out better than single coin machines as well as slots with multiple paylines.
In North America today there are an estimated 580,000 slot machines. | 
