How Slot Machines Work
The slot machine has come a long way since it was first invented by a car mechanic in 1895. They have gone from plain, totally mechancial machines to computer driven, video playing, light flashing extravaganzas. This section will deal with how the mechanical as well as the modern slot machine works.
The Classic Slot Machine
The classic slot mahcine works using a complex system of gears and levers. The main component is a metal shaft supporting reels, which connects to a handle mechanism. The braking system is responsible for halting the spin action, and small sensors determine the position of reels, to be communicated to the payout system. In addition, a coin detector registers the initial desposit and unlocks the handle. Over the decades, slot machine manufacturers have tried many approaches to arranging these different components. All in all, however, the machines have remained very similar since their inception.
When the handle of a slot machine is pulled, it rotates a hook mechanism. The hook then grabs a kicker, pulling it forward, while a catch on the opposite end of the kicker grabs a control cam piece and moves it forward. This, in turn, rotates a series of gears. A spring then pulls the control cam back, but it is slowed considerably by an assembly of gears. As it moves forward again, it releases a spring-mounted plate which extends across the back of the machine. The control cam also pulls the stoppers away from the discs. As the kicker continues moving, it fixes the stoppers against catchers located on the cam plate. These hold the stoppers in place in order for the discs and reels to rotate. The handle continues to move the kicker, which pushes the discs forward momentarily, and once the handle is pulled all the way back and the kicker has passed the discs, it is jerked backward at high speed. Paddles on the kicker then hit notches on the discs, spinning the reels rapidly. The whole while, the control cam is slowly returning to its original position, after which it pushes the cam plate back, releasesing the stoppers. Each stopper springs forward and locks into a notch, holding the reel in position once again.
The Modern Slot Machine
For the most part, the modern slot machine is designed to look and feel like older models, but its operation is completely different. As discussed in our The Secret of Slots: The RNG section, the outcome of each pull is determined by a central computer. This computer controls step motors that turn each reel and stop it at a point determined by the numbers generated by the computer. The motors are driven by short pulses of electricity controlled by the computer. Check it out here to learn more!
What are the Odds?
The law requires that the payback percentage of a slot machine is above a certain level. This varies from region to region, but usually it is somewhere around 75%. However, the payback percentage of most slot machines is much higher than the minimum - often between 90 to 98%, excluding progressive slot machines (learn more about progressive slots here). This is for the simple reason that higher payouts attract more people, and casinos don't want their competitors to have an edge. Some people have also surmised that slot machines at airports and other places besides casinos have significantly lower payout rates in comparison.