Online Casino Slot Machines

Slot games are (generally) games of chance which makes online Slot machines pretty straightforward. Or at least to a certain extent and there are Slots and there are Slots.

The payouts vary according to the Slot games. Generally these are set between 92% and 97%. Variance is a key factor in online Slot games. Many players complain of long stretched losing streaks on the higher variance Slots, but that’s something you’ll have to live with if you want the occasional big win. The lower variance Slot machines offer smaller wins, but you’ll ‘get lucky’ more often. If you are a low roller looking for a small profit then low variance Slot machines suit you better. If you have a larger bankroll and are hoping for a larger win, then you should simply try to be patient and give the higher variance Slot games a go.


  1. How to play online Slot machines
  2. How to pick the number of paylines
  3. How to decide on the bet size
  4. How to understand the different symbols
  5. How to read and understand the paytable
  6. Progressive online Slot games vs regular online Slot games
  7. Free Slots
  8. Types of Slots
  9. Online Slot machine strategy
  10. What is the % Return To Player (RTP)

Odds & Expected Percentage Returns

Now this is where it gets tricky! Obviously to a large extent, what you expect back from a game will depend largely on your strategy. And of course there are games where you canot generally affect the outcome so much – slots and keno being prime examples. It is worth noting however that online casinos generally (and this is a generalisation) offer a better return on games of chance than their Bricks & Mortar counterparts. In the UK for example, “fruit machines” are typically set at between 70% and 80% payouts, whereas the majority of online casinos will typically have expected retuns of 90% to 95% on slots. The main difference is that online slots tend to offer higher “top payouts” and therefore you are likely to hit longer losing streaks before you hit the big payouts. These big payouts often make up a fair chunk of the expected return, so without them you may find the slots seem meaner than their hardware counterparts.

Before I get into where to play for the best percentages, a final word on slots. You may find that the casinos publish payout percentages for certain groups of games, as determined by independently audited statistics.

That’s about the closest you are going to get to knowing exactly how much online casino slots pay out. However, Wagerworks software also publishes the expected returns on their slots in the “paytables”. Log into the game, view the paytable and go to the last page and you’ll find the info. In general, their slots are set to about 95%-96%, and I’d say this was a fairly accurate indicator for online casinos in general. Much better than land casino slots in general, but it’s still a muddy area, with many operators not publsihing exact figures at game level – yet anyway.

However there are some games, like Video Poker, where you can calculate the expected returns and there are several sites out there that will provide you with this information. A great example is Michael Shackleford, highly respected math-head . Michael has a reputation for integrity and mathematical prowess and he also acts as an independent auditor to OddsOn (Vegas Technology) casino software licencees. Typically, online casino video poker games will pay out between 97% and 99.5% when played to the correct strategy. Check Michael’s site for expected payouts. And even a small deviation from strategy can make a big difference, so it pays to know your game. Or alternatively, play at a Microgaming “Viper” casino where the software’s “expert mode” holds the cards for you and plays to the optimum strategy!

If anyone has any more information on odds of their favourite games, please let me know and I’ll add any good information here.

My Conclusions

Personally, as a slots and video poker player primarily, I love Microgaming software. RTG and Playtech is pretty good, but I’m put off by the fact that they don’t regulate their licenceesas as strictly, but casinos like iNetBet (RTG) and Tote (Playtech) would be good places to play. Cryptologic software is okay, but doesn’t offer me a lot over what i get at Microgaming casinos. I rarely take a signup bonus because of the restrictions, and I always use the Neteller eBank as my source of depositing and Withdrawing, mainly for faster cashouts.

How to play online Slot machines

After loading an online Slot game from an online download casino or instant online play casino, you’ll be presented with a game screen filled with reels. The classic online Slot machines will have three vertical reels but most modern online Slots will have five reels. Each reel will have 20-25 symbols on them, designed in accordance with the Slot game’s theme, and the goal is to spin the reels and hit winning combinations of symbols as the reels come to a full stop. With so many symbols on the reels this can add up to millions of possible combinations to hit! Playing online Slot machines is pretty straightforward: simply click the Spin button of the Slot game to make the reels of the Slot machine spin and sometimes you win, sometimes you lose. Some online Slot games will have a Skill Stop button so that you can stop the reels yourself. You can also choose for the Autoplay function that each Slot machine will have included. You simply click the Autoplay button to auto-spin for you and you can stop the Autoplay after each spin by clicking on the Stop button. This may all sound easy-peasy, but if you want to get the most out of your Slot games and you are a newbie to online Slot machines, you’ll want to take some time to read up on our elaborate ‘How to…’ Slot machine pages.

This step-by-step guide pretty much sums up the basics of playing an online Slot machine:

  1. Pick an online Slot machine (go with whatever design or theme appeals to you);
  2. Decide on the amount of money you want to play with;
  3. Decide on the bet size (the higher the bet amount, the higher the reward);
  4. Decide on how many paylines you want to bet (again, the higher the risk, the higher the reward);
  5. Decide whether you want to click the Spin button yourself or you prefer the AutoPlay;
  6. Happy spinning!

Note: you can easily change your parameters in between each spin. This is a pretty good way to get a feel of the game and get an idea of how different combinations p(l)ay out.

How to pick the number of paylines

Online Slot machines, one of the most popular casino games in the world, offer 3-5 reels and a winning streak could be all over the place! It might be on the top or bottom row, but it could also be diagonal or completely zigzagged. The Slot game’s software will show you each time you have a win as there are usually 9 to 30 different winning lines or paylines for each Slot game. With online Slot machines, a win doesn’t necessarily mean that symbols need to match or need to be located right next to each other. As mentioned before, they can be all over the place, but still give a win due to a certain payline. Regarding these paylines, before every spin you’ll need to decide on how many paylines you want to bet. You can’t choose which paylines you want to bet on though, just the number of paylines. If you bet on 1 line, you play for 1 coin with each spin. If you bet on 6 lines you play for 6 coins with each spin. The more paylines you bet on, the higher the chance to win and thus the higher the amount of money you spend on each spin. However, note that some Slot machines will actually have fixed paylines, meaning that you have no choice in how few or how many paylines you get to play.

How to decide on the bet size

Before you start to play a real money online Slot machine, you have to decide on the bet sizes and number of paylines you want to play. For the previously mentioned lower variances online Slot machines, you’ll find betting starting from as little as €0.01 a line. Next, you need to pick how many coins you would like to bet on a particular line. You can usually bet anything from 1 to 10 coins per line. So, for example, let’s say that a certain online Slot machine has 25 paylines, and betting which ranges from €0.01 to €1.00 a coin, and this particular Slot allows you to bet up to 10 coins per line. This means that your lowest bet would be one coin at €0.01 on one payline, so every spin you’re betting just €0.01. Or when looking at the other extreme, you could bet €1.00 a coin, 10 coins per line AND the maximum 25 paylines. This would mean that your bet per spin would be €250.00. You can look for the Max. Bet button to jump straight to this option. Every real money Slot has one. By betting a Max. Bet, you increase your chances to win and you will also have a bigger chance of triggering Bonus rounds.

How to understand the different symbols

Besides the zigzagged, 3-5 reeled, paylined craziness, online Slot machines also include an exciting feature that is called Wild symbol. Which means that you can win with just two identical symbols IF somewhere along one of the paylines, you also happen to get a Wild symbol. There could also be a multiplier attached to the win with a Wild symbol, which means that your win could be doubled, tripled, quadrupled and more! One symbol and two Wilds, will also turn out as a win. Of course each Slot machine has its own theme, features and design and Wild symbols therefore also come in all sorts, shapes and sizes.

Another intriguing symbol you should keep an eye out for is called the Scatter. The rule in general is that if you happen to collect 3 or more Scatters (in no specific order or payline location) they could generate a number of different outcomes. They could reward you either with Free spins, Bonus rounds, multipliers or coin prizes. However, please keep in mind that a Wild symbol cannot substitute for a Scatter symbol!

Most of the online Slot machines will have exciting Bonus rounds integrated that you can trigger by collecting the Scatter symbols. In general a Bonus round means that you get invited for a certain amount of Free spins. During this Bonus round, it’s usually the software that takes over in a separate (pop-up) game screen and performs an auto-spin for you. Inside the Bonus round it’s still possible to collect more Scatters and trigger even more fun freebies.

How to read and understand the paytable

Before you touch the spin button, you should take a look at the Paytable or Info icon on the game screen. By clicking on this icon you will be able to view all the game information that you need to know. You will find the different types of payouts for hitting different winning combinations, the list of symbols explained, details of Bonus rounds (if there are any) and sometimes you will also be able to see the Return to Player % (RTP).

Progressive online Slot games vs regular online Slot games

On regular online Slot machines, you will notice that the Jackpot is a fixed amount, however progressive online Slot games have a cumulative Jackpot that increases as players play the online Slot machines. It can either be a standalone machine, meaning that the Jackpot increases only on that particular online Slot, or it can be an actual network of machines where the Jackpot increases across the entire network. A game can be networked across multiple online casino’s or the network can exist just within one online casino.

Of course the Jackpot has to be “fueled” constantly. Therefore the game takes a very small percentage of each bet, hereby allowing the Jackpot to become much larger than on “regular” online Slot machine games.

Free Slots

Free Slots refer to online Slot machines that you can play and enjoy without having to wager any of your real money. The online Slot machines that offer this functionality are exactly the same as the ones you’ll find at online casinos but will generally be accessed through a demo version or ‘Free Players Mode’. But why would anyone be interested in playing free Slots without wagering and without a chance to win? Well actually, playing free online Slot machines can work in a player’s advantage.

The main reason that people play free Slots is to familiarise themselves with a new Slot game before they decide to play with real money at online casinos. By getting to know the casino games before playing, players are more likely to get a basic understanding of the way the game works. Most online casino games have their own unique Scatter symbols and Bonus rounds that differentiate them from other games. These mechanics may take a new player by surprise, especially when they are playing at an online casino for real money.

Another important reason, is that through playing and practicing with the online free Slot, a player will be able to get an idea of the variance in any specific game. This way, players will be more prepared when they deposit real money and play a real online casino Slot machine.

Then last but not least: It’s also just a lot of fun!

Types of Slots

Classic Slot Machines:

A classic online Slot machine has 3 reels and just 1 single payline.  You can also see the paytable which is the area containing symbols and numbers on the right hand side, the 3 reels with the 1 payline are on the left. On the bottom you will find the buttons which are the controls for the game.

Classic online Slots machines are traditional games based on the type of Slot games that first appeared in land-based casinos. The symbols that you will find in a Classic online Slot machines could be unique, however, more often you will find traditional fruit symbols such as cherries, melons, lemons and oranges. Other traditional symbols are single, double and triple bar symbols as well as lucky 7’s and high playing card symbols.

Although Classic online Slots are probably the most simple sort of Slot games they can also contain Wild, Scatter, multiplier or Bonus symbols and some will also have additional features such as Free spins or Bonus games. Some Classic Slot games are also progressive and a common feature is the ability to bet more than 1 coin per spin. In general, Classic Slots are 1, 2 or 3 coin Slot games.

Bonus Slot Machines:

Some Slot machines have Bonus games or other Bonus features and these are known as Bonus Slot machines. They give the player a chance to win extra prizes which is often the case with online Video Slot machines, but Classic Slot machines also sometimes offer Bonus features.

A Bonus game is triggered by 3 Bonus symbols and there are various special features to be found within the Bonus Slot machine such as Free spins, game features, gamble features or ‘pick-an-item’. It could also be a combination of all of these features and some online Bonus Slots even offer multiple Bonus games.Some Bonus games will require a degree of skill.  For example, you may have to aim and shoot at moving objects and you will be awarded a prize for each item you hit.  This is known as a skill based game.

One quality that all Bonus games share is the fact that they make your game play a lot more exciting and diverse and add an extra dimension to your online Slot machine experience.

Fruit Machines:

A Fruit machine is traditionally a British game which is often found in pubs and arcades all over the UK. Fruit machines are way more skill based than other types of Slot games and they have unique features that distinguish them.

During a game, a player will be randomly awarded a Nudge or a Hold. If awarded a Hold, this will allow the player to hold 1, 2 or 3 of the reels and keep them still during a spin. If awarded a Nudge, the player will be able to move (or ‘nudge’) 1, 2 or 3 of the reels to help complete a winning combination.

This type of Slot is not very common in other parts of the world. Due to the skill element involved, the risk to make mistakes is also higher, but that makes the Fruit machines just a bit more exciting. Usually there’s also a gamble feature involved which allows players a chance to gamble their winnings, mostly in the shape of a ‘higher-or-lower’ type of guessing.

The Cash Ladder and the Bonus Board are more reasons why Fruit machines are popular. The Cash Ladder will give you the chance to determine the next move or to gamble by guessing higher or lower by pressing either the Collect or the Start button.

Video Slot Machines:

Video Slots are computer animated Slot machines that you can play from your PC, laptop, or from a mobile device. Since Video Slot machines aren’t mechanical devices, their designs are way more creative with detailed graphics and gameplay.

Video Slot machines can be Classic Slots or have 5 reels and offer an incredible amount of paylines, even up to 100 per game. Video Slots can be found in both land-based and online casinos and the sort of themed animation that you can expect to find are highly innovative and animated symbols.  For example, during a winning combination, the symbols that create the winning combo will light up, flicker, spin around and do all sorts of crazy things, or a player is treated to some fun piece of animation. Video Slots will also have an introduction video and storyline, themed songs and sounds, Scatter symbols, Bonus games, Wild symbols, gamble features and of course Free spins. Video Slot machines are therefore way more engaging and interactive and closer to videogames than to the actual mechanical Slot machines.

3D Slot machines:

3D Slot machines can be considered the King of all animated Slots. Jam-packed with Bonus features and amazing graphics and storylines. 3D Slots can be compared to Video Slots, but with the difference that with a 3D Slot machine you get way more of everything. 3D Slot machines can be operated via touchscreen or physical buttons and the 3D part comes in with the animation, video footage, animated characters and special Bonus features.

As with Video Slots, 3D Slots bets are set via the Coins and Max. Bet buttons, and multiple paylines can be selected before playing. 3D Slot machines usually have more in-depth and rewarding Bonus features. Sometimes you can even save your position half way through a Bonus game and continue to play when you revisit and the Bonus games usually require some type of skill.

Online Slot machine strategy

Now that you’ve learned all about online Slot machines and the different types of Slots, you might want to know whether there is a strategy for online Slot games. And the answer is: YES, as a matter of fact, there is. Even though Slots are (generally) games of chance and Slots play is pretty straightforward, there certainly are a couple of online Slot machine players tips to maximize the expected returns.

The payouts vary according to the games and the casino. Generally these are set between 92% and 97%. Microgaming Slots tend to pay between 94% and 96% and offer a wider range, some less volatile (low variance) than others. Variance is a key factor when it comes to playing online Slot machines. Many players complain of long losing streaks on the higher variance Slots, but that’s something you have to live with if you want the occasional big payout. The lower variance Slots offer smaller wins more often. If you are a low roller looking for a small profit, low variance is better. If you have a larger bankroll and are hoping for a larger hit, then again, be patient and try higher variance Slots.

The only software vendor to be transparent regarding payouts are Wagerworks who publish the payouts of each Slot in the paytables. These casinos are Flash-only and are not available to US residents.

Finally worth noting are Slot tournaments that you can find at some Microgaming casinos. These are similar in concept to Poker tournaments with freerolls and buy-ins running on a regular basis. Good for the low-roller in particular.

What is the Return To Player % (RTP)

The Return to Player percentage (RTP) is the payout percentage that varies from online Slot game to online Slot game, and from developer to developer. You will be looking for an online Slot machine that has a minimum of 95%, preferably more than that. But let’s say that an online Slot has a 95% RTP. That means that (over time) out of 100 coins (100%), 95 (95%) go back to the real cash online Slot player. The rest of that percentage is obviously the online casino’s margin. Some online Slot machines will not even reach 91%, and unless for some reason you feel extremely drawn towards this particular online Slot game, you really shouldn’t stick with low payout games like that.  


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