Slot machines seems to work on a fairly simple concept. Anyone who’s ever played one is probably quite sure that they know exactly how they work, at least on a basic level. You pull the lever or push the button and the reels spin. When the reels stop, if they land in one of a number of predetermined positions, you win something. Simple, right?

What if I told you, though, that not all slot machines work that way? Many gamblers don’t know that in the U.S. there are two different type of slot machines. They are known as class II and class III slots.

The divide between the two came about because of the U.S. federal Indian Gaming Regulatory Act. This act establishes different classes for different types of gambling, with class II being defined as, “the game commonly known as bingo (whether or not electronic, computer, or other technological aids are used in connection therewith) and, if played in the same location as the bingo, pull tabs, punch board, tip jars, instant bingo, and other games similar to bingo.” Class III gaming is defined as any gaming not already labeled class I or class II.”

Most modern slot machines are designed to look and feel like the old mechanical models, but they work on a completely different principle. The outcome of each pull is actually controlled by a central computer inside the machine, not by the motion of the reels. The computer uses step motors to turn each reel and stop it at the predetermined point. Slot machine games have opaque odds and probabilities. The results are generated by a computer program called a random number generator (RNG). The only people who know the exact settings for that RNG are the designers and the casino managers.

The basic result of this law is that in most jurisdictions where gambling is legal and regulated, you’ll find class III slots and games. In Indian casinos, however, they can only offer games based on bingo. So whether you realize it or not, if you’re playing slot machines in an Indian casino, you’re actually playing bingo.

Of course this split doesn’t refer to USA online money slots.

The Birth Of Class II Slot Machines

Originally, Indian casinos did just what the law stated. They offered bingo in large warehouse-type halls. These bingo games were generally high stakes, offering much bigger risks and rewards than typical bingo games held all over the country. Still, it was only bingo. The games just didn’t provide the excitement that many gamblers were looking for. Eventually, the Indian casinos decided that if they were going to survive and thrive they needed to find a way to recreate the real Las Vegas experience.

The Hard Rock properties operated on Seminole land in Florida worked especially hard to devise a way to bring the slot machine experience into casinos where slot machines were technically illegal. They enlisted the help of engineers who had previously worked with some of the biggest class III slot machine production companies to design a backend system that would keep them within regulations. At the same time, they needed to work with slot manufacturers to design machines that would work with their new system.

The Inner Workings Of Class II Slot Machines

Today, class II and class III slot machines look virtually identical. The giveaway that you’re playing on a class II slot machine is the presence of an LED bingo card in the corner of the screen that shows results with each spin.

The reason that little bingo card is there is because that’s what is really determining whether you win or not. You’re not actually playing a slot by yourself the way you would in a Vegas casino. You’re playing along with a pool of players, in a game of bingo.

The Vice President of Operations at the Seminole Hard Rock Casino explains how it works like this, “We have a 20-millisecond window, and anyone (in the casino) pushing the Play button during that window is put in the game for that common ball draw. It must be at least two players, but the maximum is unlimited. If it is a minimum of two, one of them gets a bingo—a winning pattern.”

So, in reality, it is the bingo draw that determines if you win, not the reels. The symbols that land on the reels are really just reporting the bingo results in a way that replicates the class III slots. They are not based on an individual random number generator unique to that machine like their class III counterparts. Now, cleverly and perfectly disguised, we have a class II game that replicates the results and experience of class III gaming.

Class II Slots Vs. Class III Slots

Some people feel that class III slots are somehow “more fair” to the player because they are standalone machines that deliver results based on their own random number generator. In reality, however, the payout percentages on both types of machines are basically identical.

The class II systems can be programmed to replicate the payout combinations and rates of any class III machine. Just like there are certain odds of any one winning combination hitting on a class III slot machine, there are certain odds of any winning combination occuring in a bingo game. The programmers can match the different bingo results with the hit rate and payout scheme of any class III slot to replicate results exactly.

The bottom line is that neither type of slot is “more fair” than the other. Players will get the same odds and payouts on both type of machines. The only difference is in how the results are determined. Think of it as two roads that both go to the same destination.

To find out more about slot machines and how they work, check our Slots Guide page. Meanwhile, here are the best online casinos to play slots. Btw, online, all slots can be considered Class 3 slot machines.

Best Online Casinos to Play Slot Machines

The first time I saw people use member cards for slot games, I didn’t know what they were. I asked the man sitting next to me and he explained a few details about the rewards club. But he wasn’t using a card himself.

When I asked him why, he said he once had a card but stopped winning when he played with the card. He thought the casino was monitoring his playing and adjusting the slot game results.

This rumor has circulated both online and offline for many years. It’s normal for people to hear something repeatedly and wonder if there is truth to it. But I’ve never found any proof that casinos can change the way slot games play by flipping a switch.

What makes it difficult to combat this idea and other rumors about slot machines is the many different markets where you find them. Slot machine games are regulated by each country. Complying with different regulations may mean that a slot maker must change how its games work.

The clearest example I can give is how slot games are decided in the United States. Class II slot games decide the outcome on the basis of one random number then configure the display to match that result. Class III games use several random numbers to control the reels.

How Modern Slot Machine Games Work

There aren’t many physical slot games left. They’re all electronic now, and the electronic machines use random number generator chips to decide results.

But there is more involved than just generating a random number. The “slots” in the slot games are spaces on reels. The computers now simulate these reels.

Former and current slot machine manufacturing employees answer questions about game design on several websites including Quora. This answer was posted in September 2014, and it explains how the simulated reels are managed by software.

The programs to simulate the reels and assign the random numbers are etched into ROMs, Read-Only Memory chips. These ROMs must be physically changed by a technician to change how the game payout percentages work.

Legitimate Online Casino Operators Lease Games From Service Providers

There are over 2,000 online casinos. It’s impossible to be sure about how they all manage their slot games. But what is known about the most popular casinos is that they don’t run their slot games from their own servers.

Instead the online casinos lease game services from secure data centers. These gaming platforms are run by companies like Blue Ocean and EveryMatrix. Some of the game design companies also run their own servers, leasing resources to online casinos.

Although it would be simple for online gaming companies to switch things up, they would risk losing independent certifications if they allowed the games to be rigged.

There’s no need for casinos to adjust the percentages. They can order the percentage breakouts for house edge and return to player that they want to offer. This way, they maintain competitiveness and support long-term profitability.

Many Games Publish the Theoretical Return to Player

Some slot games include the theoretical return to player in their help screens.

If the players see that RTP has been adjusted downward, they can play elsewhere. If players only suspect that the RTP has been adjusted without proper notification, they might still leave.

Casinos need players. The best strategy to grow their customer base is to keep game rewards high enough to make the risk worthwhile.

Some Governments Regulate Return to Player Percentages

Licensed gaming casinos must comply with local laws governing their businesses. Some countries provide more regulation than others.

In the United States, commercial land-based casinos are regulated by their states. However, Native American casinos are mostly regulated by the tribal governments that own them. Each jurisdiction has the authority to set minimal RTP percentages to ensure the casinos don’t make too much money.

The 1988 Indian Gaming Regulatory Act creates the legal framework used by tribes to protect their traditional gaming activities from state regulatory laws. The act also defines the three classes of gaming and how they are to be regulated.

Class II games are regulated by the tribes but only in states that allow any kind of gaming. Only Class III games are subject solely to state regulation.

True slot machine games are Class III games. Native American casinos offer Class II bingo games that are made to look like slot games. The game cabinets must display the casino bingo games that are used to determine wins.

Class II slot machines may have reels and bonus games but they’re not really slot machine games as defined by federal law.

How Do You Determine the Odds That a Slot Game Pays?

Casinos may or may not be required to declare the return to player for their slot games. Some casinos place a plate or sticker on their slot games with a notice. Other casinos leave it to the game help screens (thus, the manufacturers) to inform players.

The games’ odds may be reported as a theoretical RTP percentage, but they could also be reported as a ratio, similar to the way lottery games declare chances of winning a prize. Either way, these games don’t have to tell you how often to expect to win a prize of any amount.

Some players merely judge the looseness of slot games by how much money they win or how often they win as they play the games.

Some players judge the looseness of slot games by how popular they appear to be. This observational strategy assumes that the crowd knows more than the individual.

One of my friends tells me he only plays slot games with low jackpots. His reasoning is that players need to lose less money for someone to win $10,000 than for someone to win $20,000.

Slot Machines May Have Programmed Payout Limits

In another post on Quora from 2016, someone claimed to have industry experience in the Caribbean.

In his post, he said that a machine won’t pay more than it has accumulated after the first month of operation. That first month establishes the limit based on the profit the machine made.

The system is designed to be random within a range of percentages. The software decides when and how much to pay but won’t go over the monthly limit.

It should be obvious that this limit could be reset.

The Games Are Designed to Be as Random as Possible

People who design and repair slot machine games express much trust in the random number generator chips these games use. The RNGs, as they are called, use the latest available algorithms at the time they are manufactured.

Math has not yet progressed to the point where truly random numbers can be generated. Mechanical devices require input from an outside source to be truly random.

The way slot game designers handle this limitation is they design the chips to generate thousands of random numbers every second. The random numbers each take a turn at being available for use by the game.

Because of the percentage payouts and internal limits they use, slot machine games don’t have to be reprogrammed to improve casino profits. Everything is designed to run with as little intervention as possible.

And that is better for the casino because the more they can intervene in a game’s function, the more likely they’ll face regulation over that intervention.

Casino game techs often say that replacing chips in slot machines must follow a special procedure (in the United States). They are closely monitored and every part must be accounted for. So, it’s less expensive for casinos if they don’t tweak the games.

Conclusion

An honest casino doesn’t need to control who wins at a slot game. They already control who can play a slot game. They can ask anyone to leave for any reason.

How Do Slot Machines Work In Indian Casinos

Naturally, casinos don’t do that. Instead. they purchase gaming systems that are designed to create an entertaining experience for patrons while legally retaining a profitable percentage of wagers.

How Do Slot Machines Work In Indian Casinos Near Me

No matter how much one’s frustration tempts a player into wondering about Big Brother Casino tweaking the game, it’s more profitable for the casino to let nature take its course.