Gambling with Random Number Generators and Spinning Wheels

Number Sequence Background, Poker Cards Spread, Slot Machine, Roulette Wheel
A few months ago, a colleague of mine wrote about 2 staples of gambling – playing cards and dice. I thought it would be fun to write a sequel to that post looking at 2 more gambling staples:

Random number generators and spinning wheels.

In a sense, all gambling games use a random number generator online of some kind. After all, a spinning wheel with numbered spaces is generating random numbers. A deck of cards is, too.

But when most gambling writers and gamblers talk about an RNG, they’re talking about something more specific. I’ll cover the specifics of that on this page.

Spinning wheels with numbers on them are used in multiple games, too – the most notable of which is probably roulette. I’ll have some observations to share about spinning wheels, too.

This might lead you to think that this page is just about roulette and slot machine games, but, as you’ll see, it’s about more than that.

Possibilities and Probabilities in Gambling

All gambling, including and especially casino gambling, involves probability.

Probability is a way to measure how likely something is to happen.

As such, it involves numbers.

Before you can understand the first thing about gambling, you need at least  general understanding of probability.

First, understand that the word “probability” has 2 meanings:

  1. It’s the study of how likely things are to happen. It’s a branch of mathematics.
  2. It’s also the unit with which you measure how likely something is to happen. In that respect, probability is like distance or time – it’s something you can measure mathematically.

The entire field of probability math starts with one definition – the probability of something is a number between 0 and 1.

Something with a probability of 0 will never happen.

Something with a probability of 1 will always happen.

Crowd of People and Casino Dealer by Roulette Table, Number Sequence

Most events have a probability of between 0 and 1. The closer the probability gets to 1, the likelier the event is to happen.

And if you know much about math, you know that any number between 0 and 1 is a fraction.

To determine the probability that something will happen, you take the number of ways it can happen and divide it by the total number of potential outcomes.

If you have a spinning wheel with 24 stops on it, and each of them has a different number, the probability of getting a specific number is 1/24.

This probability can be expressed as a fraction, but it can also be expressed as a decimal, a percentage, or as odds.

1/24 as a decimal is 0.041667.

As a percentage, it’s 4.1667%.

As odds, it’s 23 to 1.

Stating a probability as odds can be especially helpful when talking about gambling, because odds are also used to express how much you get paid when you win a bet.

For example, if the payout for picking a specific number on a spinning wheel is 23 to 1, you’d have a game where you’d break even in the long run.

If the payout were 22 to 1 (or less), you’d lose money on that game in the long run.

If the payout were 25 to 1 (or more), you’d win money on that game in the long run.

That’s the secret to how casino games are so profitable for the casino. They always pay out at odds that make you a long-term loser.

Spinning Wheels in Casino Games

The most common game using a spinning wheel is roulette, and it does have a single number bet. But it doesn’t have 24 stops – it has 38 different numbers.

To make things more interesting, each number is also assigned a color, which you can also bet on. That’s what makes roulette interesting, in fact – the number of bets available.

And all those bets offer payouts that ensure the house will win in the long run.

The inside bets have the lowest payouts. The most basic of these is the single number bet, which pays off at 35 to 1 odds. The odds of winning this bet, since there are 38 numbers on the wheel, are 37 to 1.

But you can also bet on 2 numbers, and if either of them win, you get paid off at 17 to 1. The odds of winning, though, are 18 to 1.

The most basic of the other bets are the bets on the colors red or black. If you bet on black, you win ALMOST half the time. But only 18 of the numbers are black, and 18 are red. The other 2 numbers – the 0 and the 00 – are green.

All the bets at the roulette table are scheduled to pay out in such a way that the house wins an average of 5.26% of each bet in the long run.

Another spinning wheel game that’s still found in some casinos is called the Wheel of Fortune. You don’t see it as often in modern casinos, but sometimes you do. The odds on this game are even worse than those in standard roulette.

Row of Wheel of Fortune Slot Machines, Fifty Dollar Bill

The way the Wheel of Fortune works is that you win an amount equal to the dollar amount on the stop that lands. If it lands on a slot labeled $1, you win $1 on a $1 bet. If it lands on the $2 spot, you win $2, and so on – usually up to a $40 or $50 prize.

The trick is that you have to guess which number it will land on.

You only win $1 on the $1 spot if you bet on that one to win.

You only win $20 on the $20 spot if you bet on the $20 spot.

The house edge on the bets in this game change based on which bet you’re making. If you bet on nothing but the $1, you’re facing a house edge of 11.11%. If you bet on the $20, the house edge is 22.22%.

Remember, the house edge is the average amount you expect to lose. It’s based on the difference between the odds of winning and the payout odds when you do win.

Using Random Number Generators

Most of the time when a gambler talks about random number generators, he’s talking about the computer program inside a gambling machine that generates the results. This is true of the slot machines in the casino, but also the video poker games, which are the most common games using this RNG to generate results.

The casino has other gambling machines available, too, though – video blackjack and video roulette are also becoming more common.

The biggest user of a random number generator online software, though, is the online casino.

Even though the animation for each game LOOKS like the actual game in a real casino, the results are generated by a random number generator online program.

This is true of online roulette, online blackjack – even multiplayer poker uses an RNG to generate results.

This doesn’t imply that any of these games are cheating. The odds programmed into a random number generator on those games are the same as the odds of the same game in a regular casino. It’s easy to generate a random number generator online for a roulette game, for example:

You just need a program that generates numbers 1 through 38, each of which corresponds to a stop on the roulette wheel. When you push play, the computer stops on that number.

Guy On His Laptop, Laptop Displaying Online Roulette Game with Red Stop Button

Since the machine runs through hundreds or thousands of numbers per second, it’s effectively impossible to predict any kind of pattern.

But not all online casino games use “fair” random number generators.

One popular no download casino launched a blackjack game (called “Spacejack”) a few years ago. It looks like blackjack, but it’s just a slot machine game. In other words, even though you get playing card pictures on the screen, the probabilities aren’t the same as you’d see from a deck of cards.

99% of the online casinos use a fair random number generator that has the probabilities you’d expect.

Just watch out for the 1% that don’t.

This site, of course, only recommends casinos that offer fair games with RNGs that produce the kinds of results commensurate with a brick and mortar version of that same game.

Also, when it comes to slot machines, it’s traditionally impossible to calculate the odds of getting a specific symbol and a specific combination of symbols anyway.


It’s fun to talk about the different ways casino games use randomizers to create games for you to gamble on. It gets more interesting when you compare the odds of winning with the odds you get paid off at when you do win.

Most of these methods of randomization are familiar with anyone who gambles – playing cards, spinning wheels, random number generators, and dice are the most common.

Which kinds of casino games do you prefer?