What You Need to Know Before Putting Money Into a Slot Machine

Casino Slot Machines, Dollar Bill, Yellow Caution Sign
Since slot machines make up the overwhelming amount of most casinos’ revenue, it’s a safe bet to say that you’re probably going to play them if you visit any top real money casinos.

When you walk in, you’ll probably notice how much of the casino is actually taken up by these ringing and spinning machines.

But you shouldn’t play slot machines at all until you know what you’re getting into. This post provides you with everything you need to know before putting your money into a slot machine.

You Can Play Free Slot Machines and Save a LOT of Money

I don’t know how you’re going to feel about this, but you might want to take a look at the variety of free slot machines available online. Sure, it’s difficult and borderline impossible to win money at these games.

But if you’re on a budget, or care a lot about your bankroll, playing free slots might be a good place to start.

The way most of these games work is, they provide you with a certain amount of play money to use on the game. Any money you win or lose is just play money.

Think of it like playing poker for pennies or for toothpicks. It’s just a way to keep score.

If you’re someone who plays slots and loses an average of just $50 per week, you’re blowing $2600 a year on slot machines. You might be better off putting that money into a bank account and playing free slots instead.

Most Modern Slot Machines Are “Video” Slots

I don’t think you should play any kind of game without understanding the rules.

Everyone knows that a slot machine has spinning reels with symbols on them, and the goal is to line up symbols across a pay line. Early slot machines used springs and gears to randomize the spinning of these reels.

Modern slot machines, though, use a computer program called a random number generator to provide results. Many of these games don’t even have physical reels anymore; they just have videos of reels on a computer monitor or TV screen.

Casino Video Slot Machine

But even the games which still have physical reels use that same random number generator to determine their results.

It’s important that you understand this, because it makes it almost impossible to estimate your payback percentage or likelihood of winning when you don’t know what the probability of hitting a specific symbol is.

Some symbols come up once every 10 spins, on average. Others might only come up once every 30 or even every 100 spins, which leads me to my next topic…

The Payout Percentage and the Pay Table

The pay table is the guide to how much each set of matched symbols pays off at.

For example, if you get sevens across all three reels, you might win 100 to 1 on your money, or if you get three Megabucks symbols in a row, you might win $10 million.

The payout percentage for the game is a function of the probability of winning a prize compared to the prize amount. Over time, you should get payouts that are commensurate with the payout percentage.

Here’s an example: If you played a simple slot machine game with 1000 possible outcomes, and only one of those outcomes paid out at 1000 to 1, you’d have a game with a payout percentage of 100%.

You’d lose most of the time, but if you played long enough, you’d most likely break even. But that you had 1100 possible outcomes, and only one of those outcomes paid off at 1000 to 1, the payout percentage would be significantly lower than 100%.

In fact, it would be 1000/1100, or 91%. On average, you’d win 91 cents for every dollar you wagered on the game.

Since a game that only pays off once in every 1000 spins, you wind up with slot machine games where the prizes are smaller but more frequent. You still have a jackpot, but you also have all these other smaller prizes.

But the payout percentage for the game is still less than 100%. Which means that over time, if you keep playing, you’ll eventually lose all your money.

Are Slot Machines Legal Where You Live?

If you’re playing in a land-based casino with a sign that’s visible from the street, slot machines are probably legal there. Yes, underground, illegal casinos exist in the United States, but they’re not well-publicized.

Most states, though, have strict laws regarding who can own slot machines and which kinds of slot machines you can own.

Court Gavel, United States Map

In states that allow ownership of slot machines, you can usually count on them being illegal if they’re not antiques, unless you’re operating a legal, licensed casino. But what counts as an “antique” slot machine varies from state to state.

The states have these laws in place to prevent places like bars and gas stations from offering illegal gambling. But if you live in Texas, you probably already know that many businesses ignore such laws.

How Likely Are You to Become Addicted to Slot Machines?

You’re probably more likely to become addicted to slot machines than you think. No, you’re not ingesting a substance that interferes with your ability to think clearly. But you are engaging in an activity that causes significant changes in your brain chemistry.

The release of dopamine in the brain happens when you trigger a win, or even a “near-miss,” on a slot machine.

In fact, on many multi-payline, multi-reel slot machine games, a winning spin can actually result in a net loss for the player. The brain responds the same way.

How does that happen? Well, imagine that you’re playing on a game with 15 paylines, and you bet $1 on each payline, putting $15 into action.

You get a winning combination on two of those paylines, and one of those pays off at 2 to 1, and the other pays off at 3 to 1. You win $5, but you’d put $15 into action, so you actually lose $10.

But your brain responses as if you just had a win. Slot machine manufacturers have also used the concept of a near-miss to reinforce your desire to keep playing. Gambling addiction is a big problem in some people’s lives.

Enjoy slot machines if you wish, but when it stops being fun, stop playing. If you can’t stop playing, even though you’re no longer having fun, you may have a problem and should seek professional help.

Online Slot Machines Are Similar to Land-Based Casino Slots

The mechanisms behind online slot machines and the mechanisms behind land-based casinos are the same. All the results are determined by the same kind of computer program – a random number generator.

Casino Slot Machine, Online Slot Machine Reels

How does a random number generator work? It’s not that hard to understand. A random number generator cycles through hundreds or thousands of numbers per second. When you hit the “spin” button on a slot machine, it stops on whatever number it’s “thinking of” at that instant.

You have no way of watching or following this cycle to predict when the game is ready to pay off either. You don’t have to worry about online casinos or land-based casinos cheating at slot machines. They have literally no incentive to do so.

The games are designed so that the casino has a mathematical edge that can’t be overcome unless you cheat in some extraordinary way.

Consider Video Poker or Table Games Instead

I discussed payout percentage earlier, but I want to compare that to the house edge. That’s the amount of each bet that the casino expects to keep based on the math behind the game. If you subtract the payback percentage of a game from 100%, you get the house edge for the game.

Why does the house edge matter? If you multiply the house edge by the amount you wager per hour, you’ll get an estimate of how much money you’re expected to lose.

The average slot machine player makes 600 spins per hour. If you’re betting $3 per spin, you’re putting $1800 per hour into action.

An average slot machine might have a payout percentage of 91%, which means the house edge is 9%. $1800 x 9% is the same thing as $162. That’s a lot of money to lose in an hour.

Here’s the good news! Video poker games generally have a much lower edge. The house edge varies from one game to another, but you’ll rarely find a video poker game with a house edge much higher than 4%.

This means your expected loss on that same amount of action is only $72. If you do your homework, you can find video poker games where the house edge is only 0.5%, which reduces your average loss per hour to $9 per hour.

Table games are great, too. Much of the time, you can find a game with a house edge of between 1% and 2%. But you’ll also make far fewer bets per hour at a table game. If you assume an average of 50 bets per hour at a table, even if you’re betting $10 per game, you’re only putting $500 per hour into action.

This means your average hourly loss on table games is between $5 and $10. And you’ll have just as much fun as you would playing slots.


Slot machines can be fun, but I don’t recommend making them the center of your gambling activity. Try to find games where you face a lower house edge and place fewer bets per hour.

If you just enjoy the sights and sounds of such games, try some of the free slots games you can play online. A few free spins might earn you some coin.

Playing table games or video poker are great ways to employ an actual strategy while gambling online. If slots aren’t your thing, then these alternatives might do the trick!