A bit of history
Over a century before online slots were first introduced to the world, Sittman and Pitt of Brooklyn, New York, U.S. developed a gambling machine which was a precursor to the modern slot machine. It contained five drums holding a total of 50 card faces and was based on poker. This machine proved extremely popular and soon many bars in the city had one or more of the machines bar-side. Players would insert a nickel and pull a lever, which would spin the drums and the cards they held, the player hoping for a good poker hand. There was no direct payout mechanism, so a pair of kings might get the player a free beer, whereas a royal flush could pay out cigars or drinks, the prizes wholly dependent on what was on offer at the local establishment. To make the odds better for the house, two cards were typically removed from the deck: the ten of spades and the jack of hearts, which cut the odds of winning a royal flush by half. The drums could also be re-arranged to further reduce a player’s chance of winning.