Slots Machine game review Online & Mobile

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Slot machines (also called slots) are the most popular games in online casinos, as well as in land-based casinos in Las Vegas, Macau, Monaco or other places in the world. The success can be explained by the simplicity of the games, as well as the fact that you can win a huge amount of money in just a single spin. 

It is similar to a lottery game and it is not uncommon to see a player win €1 million or more with just a small bet of only €1. Another similarity to lottery games is that there are no particular strategies that help you win, although there are still some tricks and techniques that can help you increase your chances of winning.

On this page you can find a selection of online slots that can be played with or without registration. You can play the games for free with play money for as long as you like without having any risk of losing money when you discover the different types of games. You can even find a list showing you the most played slots and the most profitable slots in 2016.


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How does a slot machine at an online casino work?

To play the games in demo mode is a great way to try them out and test different strategies without taking any risks of losing money. However, if you want to experience the real thrill of a slot machine you will have to play it for real money. But before you place real money bets you should know the rules of the games, and you can find them in more detail on this page.

Playing a game

Slot machines are very simple games. You just have to push a button (or pull a lever) to start the reels spinning. Once the reels have come to a stop you can see if you have managed to get a combination of paying symbols, usually a sequence of identical symbols on a pay-line. If that is the case you will get your winnings paid out, and you can start a new game.

This is a simplified summary of what happens in a spin. Some slot machines have special features or special symbols, which you will find out about more later. Before you start a spin you can choose your wager and select how many coins you wish to play. The coin value determines the amount of money you assign to one of the credits that you are playing with. You can also often choose to change the number of pay-lines played. You will soon also find out more about pay-lines and reels.

The reels (mechanical or digital)

Mechanical Slot Machine

The reels are probably the elements that you will notice first when you look at the slot for the first time. The reels are like large wheels with symbols drawn on them, and you can win money with those symbols.

The first slot machine in history had three reels that were rotated mechanically. Today, these types of 3-reel games are still called mechanical slot machines. They are also sometimes referred to as one-armed bandits.

Over time, more reels were added to the games. The mechanical games made room for the digital screens, that spin the reels in the same manner as the mechanical games. These digital types of games are called video slot machines.

If you are playing on the Internet, everything is displayed on a screen, which means that technically all slot machines are video slot machines. However, it is still distinguished between mechanical slot machines that simulate real reels and the digital video slots.


The first slot machine in history paid you a win when you managed to get three matching symbols in the centre line in the middle of the reels. The game had only one pay-line, and more pay-lines appeared in later games. You were then able to win with symbol combinations on horizontal connections on any reel or even diagonal combinations stretched overall reels. The games usually offer you the option to select how many pay-lines you want to enable before starting the game. The amount of pay-lines you play also has an effect on your bet size.

A video example on Youtube

To finalise this section about the rules of a slot machine, here is a video that shows you what happens during a short game session. The game in question is The Wild Chase, an excellent slot.

Tip: how to increase your chances at winning at a slot machine

So, this is the basic functionality of a slot. But I will also go a little further and tell you more about slots, such as the concept of optimising your chances of winning (without using complex strategies), which will make the games a lot more thrilling and rewarding!

Knowing the return to player rate on your bets

I hope that this expression, which is a bit of a mouth full, will not scare the readers, but it is a very important piece of information that should not be neglected. The return to player rate, also called payout rate is the percentage that indicates how much the players will get back on average from their bets in the form of winnings. For example, a slot machine that has a return to player rate of 97% pays back 97 cents to every euro spent.

You can sometimes find the return to player rate of the slot game in the pay-table, other times you have to look on the Internet. The return to player rate can be an interesting factor to keep in mind when choosing a slot, as it can increase the chances of winning when you only play slots with a high payout.

How the volatility affects the winnings

The return to player rate indicates whether or not a game has a generous payout. However, it does not really tell you what type of game you can expect. The slot machine volatility (also called variance) indicates the risk of a game and the payout frequency of higher and lower winnings.

A slot machine with lower volatility will regularly pay out smaller amounts of money. On the other end is a slot with higher volatility that pays out higher amounts, but less frequently. There are also games with medium volatility where you can win lower and higher amounts more or less frequently.

Knowing how much you can win according to the pay-table

So, now you have information about the payout rate and the volatility, but this tells you very little about how much you can actually win at a slot machine. This information can be easily found in the pay-table of the game. This table shows you the amounts of money or credits you can win according to different winning combinations on the screen. You can also see how the pay-lines are distributed on the reels, and find information about the special symbols and features (you will find out more about them soon). Ohe pay-table gives you all the information you need to understand what the game has to offer in terms of winning possibilities.

Paytable example

Winning a jackpot

You can find the amount of money that you can win in the pay-table of the game, including the jackpot. This is the maximum amount that you can win in a single spin. The jackpot is usually fixed, but there are some that can grow as players play the game. These are called progressive jackpots and they gradually increase in value, sometimes they can even reach more than 1 million euros.

Online slot machines bonus features

Online Slot Machine Bonus FeaturesSpinning the reels in an attempt to get a combination of identical symbols in order to win money is the same in most slot machines. However, some of these games have bonus features that give you additional opportunities to win money. These can either be individual symbols with special abilities or special features. You can find out more about the symbols and features in the paragraphs below.


Some symbols have the ability to stand in for other symbols in order to create the most profitable winning combination possible. The symbol is called the wild symbol, and it can come in different forms, such as:

  • the Stacked Wild which is a symbol stack that can occupy more than one field on the same reel, usually up to 3 or 4 spaces,
  • the Expandable Wild that transforms as soon as you get it on the screen. It usually expands onto all the positions on the reel,
  • the Sticky Wild that will be locked in its position for subsequent spins,
  • the Multiplier Wild that multiplies winning combinations achieved with the wild symbol.


Some symbols have the power to award you money without the symbol having to appear on a dedicated pay-line. It is simple enough to have a certain amount of these scatter symbols anywhere on the reels in order to receive a payout.

Free spins

Some slot machines have a free spins feature that starts when you get at least three scatter symbols. The free games are played without you having to bet any money, and you can win some decent amounts of money in them. Depending on the slot that you are playing, there may also be other ways to trigger the free spins feature.


Free spins are usually between 10, 20 or 100 free games. When you receive a lower amount of free spins, there are called Re-Spins, and they can be 1, 2 or 3 game rounds are sometimes played with certain symbols held in place.

Bonus games

Some slot machines also offer the chance to trigger a bonus game. These are usually mini-games that are not played on the reels. The bonus games are played on a second screen where you can choose between different items that award money. There are also some more advanced bonus games that allow you to play more elaborate strategy games, or they look like a videogame or a board game. These are called skill games.

Click Me

Many slots have a feature called Click Me which shows you usually 3 or more symbols can look the same or different. You will then have to click on one or more of these items in order to win money.


Some slot machines offer you the opportunity to stake your winnings in a gamble feature. This gamble is usually not played on the reels, but on a different screen, just like the bonus game. The gamble game can be a coin toss or a card game where you have to guess the colour (black or red), or the card suit (heart, clubs, spades, diamond) of the next card, and when you guess correctly your winnings will be doubled or quadrupled. It is usually possible to play the gamble more than once in a row.

Tumbling reels

The features mentioned above are triggered when you get the corresponding symbols on the screen. The tumbling reels feature is a little different and characterises a particular type of slot machine. These slots have no reels that are spun, instead, the symbols fall from the top of the screen. When you get a winning combination, the symbols of the combination disappear and make room for the symbols above them. This gives you a chance to get a new configuration of symbols on the screen which in turn may lead to subsequent winning combinations. This will continue until you get no further winning combinations.

How to choose a slot machine type in an online casino

You can enjoy a large selection of different slot machines when playing in an online casino or in a land-based establishment. These games can be divided into different categories, and I will introduce you now to the most popular types. For example, in the category of online slot machines are free slot machines, flash slot machines or no-download slot machines. However, these games do not really need their own category, because any online slot machine can potentially be played for free, without flash for without a software download.

Aztec Gold Megaways slot on different screens

Mechanical slot machines

I have already mentioned the mechanical slot machines at the beginning of this text. These games use real reels that are operated mechanically. These were the first games ever developed and they usually have only a few pay-lines (sometimes only one) and usually 3 reels, but sometimes also 3 or 5. These games also normally do not have special symbols or features, although there are some games that do.

Video slots

Video slot machines usually have at least 5 reels, but there are also some games that have 3 or 4 reels. They usually also have special symbols and features and a lot more pay-lines than traditional games.

3D slot machines

Over the last few years, a new video slot category emerged and became more and more successful. These are the 3D slot machines with animated 3D graphics that remind of video games or movies. These games offer funny animations and stunning cinematic that make the games a lot more entertaining.

Slot machines on smartphones or tablets (iOS / Android)

There are slots you can play through the internet from your computer, and you can also find HTML5 slots that can be played from a mobile device, such as iPhones, smartphones, iPads or tablet computers using iOS or Android operating systems. This applications (apps) for online casinos are the perfect way to spend time while waiting for someone or when you are on the go. You can also play these games when you are on vacation, during your lunch break at work or when you are with friends or family.

You can also find many other types of slot machines, such as multi-reel machines, fruit machines (in pubs in the UK), virtual reality slots, interactive slot machines, social media slot games, etc.

Slot machine developers and popular game categories available on FeedBACK Casino

As you can see, the universe of slot machines is very diverse and varied. There are games for virtually every taste. Above you can find a filter system that lets you choose filters to find the games that might be of interest to you. In the filters, you can also select from different developers.

The online casinos do not develop the games that you can find in the game lobby. The software developers are responsible for designing those games. Not all these developers are equal, and not all casinos offer the same games. Some of the most popular developers are Betsoft, Playtech, Microgaming, Netent, Rival, Play'n GO, NextGen Gaming and Leander Games. You can find them in our selection of games as well.


To finish this guide, I would also like to mention the video poker slot machines. These games are a different type of game that we talk more about in a separate section. They are a mix between a slot machine and a solitaire version of the draw poker variant. In order to win money, you have to manage to get a poker hand (one of the common poker hand combinations), and you usually get two attempts. One is the first hand of which you can select a few cards to keep and then have the rest exchanged in the second deal.

feedback FAQ - Slot Machine
How do I play slot machines?
To play a slot machine, you simply have to spin the reels by pulling a lever or pressing a button. Depending on which combinations of symbols you get on the screen, you will win money or lose your bet.
What is the coin value of slot machines?
This is the value of coins, sometimes called credits that are used when playing with slot machine money.
How to win a jackpot at a slot machine?
You win the jackpot of a game if you get a symbol combination with the rarest symbols on all paylines. The maximum payout of a game round is also known as a jackpot in a slot machine.
What is a progressive jackpot at slot machines?
A progressive jackpot is a jackpot that is not fixed but grows slowly with the bets of players. In such a game, a small portion of each bet is withheld and put into the jackpot.
What is a wild symbol at slot machines?
The wild symbol plays the role of a joker and therefore can stand for other symbols to form or complete winning combinations.
What is a scatter symbol in slot machines?
The scatter is a symbol that you can use to win if it appears a minimum number of times on the screen, but it does not matter what position it is on the reels.
What are free spins at slot machines?
Free spins are free game rounds. The reels will then spin without you having to spend money and you have a chance for great wins with them.
What is a payline on slot machines?
In order to win at a slot machine, you have to get several identical symbols on a pattern of spaces on the reels. These patterns can be laid horizontally or in other patterns over the reels, some even vertically.
What is the payout on a slot machine?
This is the average percentage of the wager that will be re-distributed to the players. This means that if you play a slot machine with a theoretical payout of 97%, you will receive an average of 97 cents for every euro you play, but this value is theoretical and would require you to play several million rounds of play.
What is the variance of a slot machine?
The variance describes the risk that you can expect at a slot machine. Low variance means frequent, but lower profits, and high variance means rare wins, but the chance to win much higher sums.
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