Ask the Slot Expert: Changing the hit frequency on a mechanical slot machine

Can you tell me if there's an adjustment on Mills mechanical slots to increase the frequency of payouts? I can't find anything about it in the service manual I have.

Granted, I know it's normally a game of chance, but it would be a little more interesting if it paid out more often. I have a 1948 Golden Nugget machine, most likely a reproduction.

For roughly four score and seven years, the hit frequency on a slot machine was determined by how many times the symbols appeared on the reels. During this time period slot machines were mechanical or electro-mechanical. Each stop on each reel was equally likely to land on the payline and there was no way to alter that (at least no legal way). The machines used complicated mechanisms to randomize where the reels stopped. The machines then sensed where the reels stopped and paid off accordingly. The only way to make a machine hit more frequently was to add more symbols to the reels.

In the mid-1980s, computers took over the slot machine. The result of a spin was determined by the Random Number Generator (RNG) and the machines used (stepper) motors to spin the reels and stop them at the precise locations to display the result determined by the RNG. Once the purpose of the reels was changed from determining the result to merely displaying the result, it became possible to change how frequently a symbol or blank on a reel lands on the payline. The computer program running the slot machine uses virtual reels to control how frequently a blank or symbol lands on the payline. The more frequently a blank or symbol appears on the virtual reel, the more frequently that blank or symbol will land on the payline.

Back to the mechanical slot, the only way to make it hit more frequently is to make winning combinations more likely by adding one or more symbols to the reels.

Making the machine hit more frequently is tough, but making it hit less frequently is relatively easy. I've read stories of dishonest casino operators putting "bugs" on the reels to make it impossible for a reel to stop at that location.

Your question made me reflect on innovations on today's slots versus what counted for innovation generations ago. Today we have high-resolution graphics, high-fidelity sound, even chairs that shake.

I remember an ad for an old mechanical machine that read something like this: "For years, all slot manufacturers have agreed that three cherries should pay 10 coins. On our new super-duper slot, three cherries pays 12 coins."

Now that's innovation.