Mechanics Behind Slot Machines

Mechanism of a Classic Slot

The original mechanical design was built around a series of levers, axels, gears and a brake. When a coin is entered into the slot, it activates the release of the brake. The central axle has a metal shaft supporting the reels. There is a second axel located below the central axle which supports a kicker (the two axles are connected by a series of cog wheels). The second axel is just a length of metal that has three pedals attached to it.

The pedals on the kicker are designed to push against notches on sides of the three reels. The axel is joined to the handle. When the handle is depressed, it initiates the movement of the machinery. The pedals push against the notches and initiate a spin. The timer is activated and this controls the length of the spin. The length of the spin is determined by the rotation of a flywheel and is set by the manufacturer.

Different manufacturers arranged the mechanics of their machines in different ways. The outcome, however, is the same. The pedals on the kicker initiate a spin when the handle is depressed. When the spin is completed the brake locks again until the next coin is inserted. When this occurs, the whole process is repeated.

Mechanism of an Electronic Slot

The invention revolutionized the classic slot. The new generation of slots had no mechanical moving parts. A computer chip, called a Random Number Generator (RNG) was incorporated into each machine. The RNG selects thousands of numbers per second which govern the outcome of the spin – win or lose.

At the exact moment the “Start” or “Play” button is depressed, the RNG uses the number generated at that exact moment to determine the outcome of the spin. With the RNG system in place in electronic slots there is no way to forecast when a jackpot will be paid. Theoretically the probability of a jackpot being chosen and the start button being depressed at the same time are astronomic.

The manufacturers of electronic slots have built in a program that is called a “payout percentage”. This is set by the casino and not by the manufacturer. In some casinos there will be an announcement of the average payout of slots. This is not a legal requirement and is only done to encourage players to keep playing.