Slot Machine Odds Explained – Slots Probabilities and Payouts

Sergio Zammit
Sergio Zammit | Verified by Mark Hoover
Last updated: | 12 min read

While some elements of a slot are predictable, like Return to Player (RTP) and volatility, slot machine odds are not. Slot machines work on Random Number Generators (RNG), which generate anywhere between one and a million outcomes every second. Understanding how RNG works will help you understand slots odds better and master your game plan.

We will take a more in-depth look at the math behind the odds. We will also provide some slot machine options and explain why we recommend them. Keep reading to discover all there is to know about slots odds.

bonanza slot slots odds

What are Slot Machine Odds

While you probably want to know what are the odds of winning on a slot machine when you play, slot machine odds are random, and various factors can determine the winning chances.

Software developers go through various testing processes when developing their games. This includes looking at the number of symbols, the frequency of payouts, and any bonus features like free spins, multipliers, or wilds, which also affect the odds.

The developers will run millions of spins on a simulator, and once they have the results, they can establish the win percentage of the slot and adjust the number of symbols and payouts if they are higher or lower than intended.

However, we must point out that the developer cannot manipulate a slot’s mechanics once it is released.

Factors Affecting Slot Machine Odds and Outcome

Every casino game has different types of odds, and various factors will influence slot machine odds. Let’s look into what they are and how they affect your gameplay.


The RTP or Return-to-Player is the return to the percentage of the money paid into them that online slot games will return to players over their lifetime. The industry average is 96%, with some higher and others much lower.

An example of how RTP works is as follows. Suppose you were spinning a slot machine with an RTP of 96%. Theoretically, for every $100, the casino will retain $4, and $96 will be paid out again as winnings. However, this doesn’t mean that you will personally win $96 for every $100 you play, as there are no guaranteed ways to beat the odds. Every player will have an entirely random outcome, even if playing the same slot game at the same wager.

Slot Volatility

The slots’ volatility is another essential factor to know and will also affect your outcomes. Volatility is usually rated as:

  • Low
  • Medium
  • High

However, you can also have a slot with a low to medium or medium to high volatility. If you play a low volatility slot, you will have more frequent winning spins but with smaller payouts. A high volatility slot typically has a high winning potential but will pay less frequently. You should have a good mix of winning and non-winning spins on medium volatility online slots.

House Edge

The house edge is what the casino keeps from any games you play with them; essentially it is the opposite of RTP. For example, if a slot has an RTP of 96.50%, the house edge is 3.5%. So, theoretically, for every $100 spent on the game over an extended period of time, the casino keeps $3.50.

However, this is not cast in stone, as it takes millions of spins to get an accurate house edge. Same goes for other casino games and if you go in depth on the roulette odds, for example, you’ll see that calculating house edge can be a science.


The basic calculation for the probability of winning on a slot is to find the number of possible symbol combinations and divide it by the total possible winning combinations. However, a combination of factors determines the probability of winning at online slots, including the number of reels, the symbols on each reel, and the game’s rules, so even with this calculation there are no guaranteed results.

Payout Percentages

The payout percentage is another name for RTP. It’s a good idea to remember both terms when researching slot machine odds, as some sites will only use one or the other.

online slot odds vs land-based casino odds

Online and Land-Based Slot Odds – Comparison

While the basic principles behind land-based Vegas slot machine odds and online slots are the same, there are also differences in the gameplay experience. The first one you might notice is that you have an expanded selection on casino sites since there is no shortage of space when playing at online venues.

Online casinos also have significantly lower overheads than their land-based counterparts. When you play online slots, the slot machine odds are a few percentage points higher due to lower costs. Online casinos don’t require as many staff and don’t have to pay rentals, electricity, etc., so they pass the savings on to the player and increase the RTP for us.

Another thing to factor in is accessibility. With online slots, you can play anytime and anywhere. Accessing a land-based casino will usually involve traveling. However, nothing will beat the thrill of the land-based real-life casino experience for some players. If you want to know more on this topic, check our guide on how to play slots online.

Slot Machine with the Best Odds

If you want to find the best slot machine odds, then there are a few factors to consider. The main areas you want to explore are as follows:

  • RTP Rate: The higher the rate, the more chances of having winning spins.
  • Low Volatility: If you play slot machines with low volatility, you will have more frequent smaller wins.
  • Number of Paylines: The more paylines, the more ways you can win. While some machines have fixed paylines you cannot adjust, others you can play on fewer lines. We always advise playing maximum lines to ensure you don’t miss any winning spins.
  • Bonuses: Triggering a bonus feature, like free spins, Increases the odds of more significant wins. Look for slot machines that have one or more bonus rounds.

While some slot machines may have all four criteria mentioned above, some may only tick two or three boxes. If the slot’s other features compensate for the missing element, it may still be a good option.

Let’s take a look at five very different slot machines. We will compare the RTP, volatility, paylines and any bonus features. It will help you understand more about what to look for and help you make your slot picks.


Starburst, by NetEnt, is one of the most iconic slot games you can play. It was an instant hit when it was released in 2012 and has remained a player favorite with its fun and glittering space theme. It is an ideal slot for beginners, and has a straightforward layout of 5X3 and ten fixed paylines. You can form winning combinations across the paylines from left to right and right to left.

starburst slot slot machine odds

Its main appeal is its high RTP of 96.1% and low volatility. There is only one bonus feature: an expanding Starburst wild. When a wild lands on one of the middle three reels, it will expand to cover the reel and reward a respin. If you land another wild, both remain on the reels, and you get another respins. You can trigger this up to a maximum of 3x. It triggers frequently, and due to this slot’s low volatility and high RTP, you will usually have small but frequent wins.

Starburst’s maximum win potential of 500x the wager is lower than other slot machines with the best odds, but when you play, your funds should last longer than with a high volatility option.

Sweet Bonanza

Pragmatic Play is the brains behind this slot loaded with sweet candy treats. It has a layout of six reels and five rows, but there are no paylines. It is one of the ‘pay anywhere’ slot machines. At least eight matching symbols must fall anywhere on the reels to form a winning combination. Another feature of this slot is its cascading reels, where on every winning spin, any winning symbols drop off the reels, and new ones drop in until no more wins are possible.

slot machine odds sweet bonanza slot

Sweet Bonanza is an excellent choice if you have been considering what slot machines have the best odds. It has an above-average RTP of 96.48% and medium volatility. So when you play it, there should be a mix of winning and non-winning spins.

The main appeal of this game is its free spins feature and the maximum winning potential of up to 21,100x the wager. To trigger free spins, four lollipop scatters must land together. You will receive ten free spins, and candy bomb multipliers also land. They start at 2x the bet and go up to 100x. If they land during a cascade, they remain on the reels. If more land, they remain, too. At the end of the cascade, any multipliers combine and multiply by the amount of that winning spin.

Money Train 3

Money Train 3 is part of a series of four Money Train slot machines from Relax Gaming. It has a layout of five reels and four rows with 40 fixed paylines. It has a futuristic Western theme and an RTP of 96.1%, which is slightly above average.

It has high volatility, so your odds of winning spins decrease but the value of any wins may be larger, with a maximum win potential of 100,000x your bet. It is more suited to high rollers and players with significant bankrolls, as it can deplete your funds quickly.

slots odds Money Train 3

If you land three scatters, you enter the respins feature with persistent symbols. These symbols will add 12 modifiers to the reels, such as money, wilds, expanding, and collector symbols. Cash values are added to your balance when money and collector symbols land together. Any new symbols that land set the reset counter back to three.

Mega Moolah

Mega Moolah is one of the top progressive jackpot slots from the software developer Games Global. Its layout is three rows and five reels with 25 fixed paylines. The theme is safari-based, and even though it was released in 2006, it remains as popular today as when it was launched. The progressive jackpot has made many players millionaires. Its biggest jackpot prize was €19.4 million to a Belgian player in 2021.

Mega Moolah slots odds

With an RTP of 88.12%, it rates lower than our other slot game examples in this regard. However, you have a chance of winning one of the four jackpots on offer. It has low volatility, so you have a fair mix of winning versus non-winning spins. The maximum win potential is 1,920x the bet in the base game.

The progressive jackpot feature is triggered randomly. You will spin a wheel with various segments, and win the jackpot amount that it lands on. You can also trigger 15 free spins with three scatters; here, the payouts are tripled, and you can retrigger with more scatters.

Mega Joker

The best odds slot machine is Mega Joker by NetEnt, which has a classic fruit theme and an RTP that can go up to 99%. To achieve the highest RTP, you have to bet the maximum amount, but this will make your jackpot prize much higher. It was released in 2013 and has high volatility.

Its layout is as straightforward as slot machines get, with three reels, three rows, and five fixed paylines. You must land three matching symbols left to right to form a winning combination. The features are the Super Meter and the Jackpot.

Mega joker slots machine odds

Suppose you bet a maximum of ten coins on all active paylines and land a winning combination. In that case, you have two choices. You can collect your winnings or activate the Super Meter, which increases the risk and your chance to scoop a payout of up to 2,000 coins.

You can see the value of the progressive jackpot at the bottom of the screen. You have to spin the maximum wager of $20 and land three jokers on a winning payline to receive the jackpot balance.

Can You Trick a Slot Machine?

The simple answer is no, you cannot. There is no way to make a slot game payout due to the RNG and the complete randomness of each spin. Each player’s chances of winning slot games are the same as the next. Some slot games, like Money Train 3, have a bonus buy feature. There is no guarantee you will win more than you pay, though, and the average price is 100x the wager. If you want to find out more about this topic, check out our guide on how to win at online slots.

Don’t Forget to Play Responsibly

Online slots are a game of chance; you must ensure you play them responsibly. However, due to their engaging graphics, colorful symbols, and enticing background music, it is easy to lose track of time when playing slots. Therefore, we recommend that you follow our safe gambling principles. These include:

  • Be mindful of the time you are spending gambling and that it does not interfere with your personal or professional life.
  • Only ever deposit and play with money you can afford to lose, and set a monthly or weekly budget, whatever suits your bankroll for the best. If you deplete your funds, do not deposit more to attempt to chase your losses, as it can quickly spiral out of control.
  • Take regular breaks. You can set handy session limits where a pop-up will remind you how long you have been playing online or log you out until your next session.

There are many other tools and resources for players on our website and at reputable online casinos. If you feel you may be at risk, you can take a self-assessment test and assess if any next steps are needed.

Slot Machines Best Odds FAQ

What are the odds of winning in slot machines?

Slot machine odds are entirely unpredictable. Although each slot game will have an RTP percentage, the randomness of each spin means that the odds are impossible to calculate at an individual level.

What slot machine game has the best odds?

The Mega Joker slot from NetEnt has the best odds. It has an RTP of 99%. However, to achieve that RTP, you must bet the maximum. The lower you bet, the lower the odds. Another slot game with some of the best odds is Blood Suckers, also from NetEnt, with 98%.

Is there a secret to winning on slot machines?

No, there isn’t. It is a game of chance, and if there were a secret, the casinos would be out of business. The house edge means that the casino will always be up over time.

What is the 5-slot machine strategy?

The 5-slot machine strategy was developed by a YouTuber going under the name of Professor Slots. He claims your chances of winning increase if you only play five spins on a slot machine. No matter the result, you move on to the next slot, play another five, and so on.