Apr

12

2017

# Slot Reels and the Frequency of Winning Symbols

Not all slot reels are created equal, regardless of whether you’re playing video slots or games with mechanical reels.

Video slots were on the mind of a reader recently who asked if all five reels have to bet the same.

“If I know one video reel is 100 symbols long before it comes around again and has one of the highest-paying symbol, does that mean the others have to have one of that symbol too?” she asked. “Can they have two or three or none?”

The short answer is that the reels don’t have to be the same.

You can see that in games that have bonus trigger symbols only on reels 1, 3 and 5, for example. Clearly, those three reels are different than the other two.

Video slots can have different quantities of each symbol on different reels. However, all payoffs advertised must be available. If the pay table for a five-reel video game shows a jackpot for five exploding star symbols, for example, then programming a reel with no exploding stars is not an option. That would make the advertised five shooting star payoff impossible, and that’s illegal.

Outside those constraints, game designers are free to vary the frequency of symbols. If the gamemaker wants players to get frequent payoffs for three shooting stars but make the five-star combo rare to make big payoffs possible, then it can use more star symbols on reels 1, 2 and 3 and fewer star symbols on reels 4 and/or 5.

The same principal applies to reel slots, although the method is different. Reels have to be small enough to fit inside machine casings, which limits the number of symbols per reel. So programmers use a virtual reel, assigning different quantities of random numbers to each symbol or space.

Each reel might have only one jackpot symbol, but the programmer could assign three random numbers to that symbol on the first reel, two on the second and one on the third.

That’s just an example. The programmer can assign whatever quantity of numbers is needed to each symbol to arrive at desired odds for the game. And just as on video slots, jackpot symbols can occur with different frequencies on each reel.