Online slot machines : Our detailed review

70% of the revenue earned in online casinos comes from slot machines, making it one of the most popular games. In concrete terms, they aim to provide an interactive gaming experience, reproducing their physical counterparts on the internet. Slot machines do not require any particular strategy. In an online casino, all you have to do is bet a small amount of money, press the button and wait for the result. If the screen shows similar patterns, you win! The principle is therefore simple, but be careful: there are several types of slot machines and this article aims to give you an overview of them.

3-reel slot machines

It was in the 1990s that Microgaming launched the first online slot machines. At that time, they had three reels. These machines are thus the oldest. They are also the ones with the highest probability of winning. It’s mathematical. With a machine with 40 symbols on each of the 3 reels, we will have 1 chance in 16,000 of winning. On the other hand, on a machine with 5 reels with 40 symbols each, the probability of winning is 1 in 6.4 million. Machines with a lower probability of winning, however, offer a bigger jackpot!

 5-reel slot machines

Five-reel slot machines were developed in the 2000s, notably by Cash Splash.  They are currently the ‘standard’ in online casinos. By switching from three to five reels, you will have a completely different gaming experience. Indeed, technological developments have led to the introduction of 3D slot machines with powerful algorithms and greater possibilities in terms of animations, movies or even treasure boxes with mini-games. The aim here is to satisfy the requirements of the customers by offering an atmosphere as close as possible to the casino. Many suppliers are involved in these slot machines, from Rival Gaming, Topgame Technology, Cryptologic, Microgaming or Playtech. This movement goes hand in hand with a story telling of the slot machines: So you can play with your favourite characters from series or films or relive historical events.

These advances can sometimes make the game a little complex to understand as the paytable becomes less easy to understand and the features you need to understand may differ from one game to another, between bonus, scatter, wild or free spin.

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Multiline slots

These are machines that have several payment lines. The objective is to bet on some of them to win. There are up to 50 paylines that intersect.

Slots in « avalanche » mode

They are also known as « cascade rolls ». This mode is one of the novelties of video slot machines. The principle is simple: it consists of changing the symbols of one winning combination by others which in turn result in bonus combinations. Bonus combinations usually give you the opportunity to increase the payout multiplier. This type of game increases the chances of winning by allowing players to clear an entire line of symbols. Avalanche mode can be found on Sugar Pop 2 or Gonzo’s Quest.

Double or Quit Slots

The notion of « double or nothing » has the merit of being clear. The player can bet double his winnings. This is a risky bet, but also a trick to be used with caution. It’s best to be aware of the rate of return and the volatility of the winnings of the slot machines involved. Double or nothing is built into most slot machines and always comes in the form of a draw, as in Deuces Wild.

Progressive Slots

Here, the jackpot is progressive and increases according to bets placed on the same location. Unlike traditional jackpots where the starting bet never changes, progressive jackpots start with a small amount and this increases as the players’ bets increase. This means that players have a better chance of winning a lot, since several people are playing at the same time on the same machines and therefore raise the jackpot. Some progressive jackpots can take more than a year to be won and it is likely that a machine that has just offered a jackpot will not do so again in the near future. However, there is no proof of this. This feature is built into the slot machines of Microgaming with Mega Moolah or PlayTech with Gold Rally or Diamond Valley.



We see continuous innovation in the world of online slot machines. Since the birth of online casinos, slot machines have always been at the centre of the casino offer. The growth of online gaming software publishers has led to the development of a huge range of online slots. The competition is great and therefore boosts creativity. The explosion of new functionalities, the attractiveness of progressive jackpots and the valorisation of official licences (series, films or video games) have seduced players. Today, slot machines represent the sinews of the casino war. Now there are even online casinos specifically dedicated to slots, with multiplayer slot machines. The most popular slots in recent years are Sweet Bonanza from pragmatic play, The Dalai Panda in Europe from iSoftBet, Narcos, Vikings from Netent, Wild Warriors from Playson or Force of Nature from Leander Game.

FAQ : Slot machines

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    What are the best casinos to play slots at?

    Here is our selection of the top online casinos for playing slots:

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    How to win at the slot machines?

    There are three tips that can help you maximise your chances of winning:

    • Minimum bet
    • Redistribution rate
    • Payment Bank

    Consult our complete guide by clicking here

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    How do I play the slot machines?

    You need to know the rules of the slot machines. Also pay attention to the type of machine (classic, progressive …) and start betting. You must also take into account how paylines and symbols work.

    Click here to follow our dedicated guidelines.

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    How do I choose a slot machine?

    There are several ways to choose to play slots:

    • volatility
    • Bonuses and jackpots
    • Betting possibilities

    Click here to see everything!