Slots with the Avalanche (cascading) mechanic explained

Added: May 25, 2022

Last updated: April 23, 2023

More and more online slots make use of the avalanche feature

We see that the Avalanche mechanic (or Avalanche feature) has become increasingly popular since 2016-2017. This mechanic is also called the Cascading mechanic or Tumbling symbols mechanic.

The idea is simple. If you win, you gain a free re-spin, and the winning symbols disappear and make way for new symbols. This combination is called a reaction. This way,  you get a new chance to make another win.

If you win again, you gain another free re-spin, which continues until you fail to make a new win.

High RTP
Gonzo’s Quest
High RTP
Monopoly-megaways slot review
Monopoly Megaways slot review
High RTP
reactoonz 2 slot play'n GO
Reactoonz 2 slot review (Play’n GO)

In some exceptional cases (e.g. Play’n GO’s Black Mamba), no new symbols appear, and therefore the number of symbols on the grid decreases with the re-spin.

This feature is prevalent, as it offers so many more possibilities for game studios to vary the gameplay.

Most Megaways slots and grid slots make use of this mechanic, and these slots have become incredibly popular over the past couple of years. Experienced slot players seek more challenging slots, and this feature helps!

Netent’s famous Gonzo’s Quest slot (below we show it) was the first to introduce this powerful mechanism. Nowadays, you can ask yourself why they didn’t trademark this feature!

Explanation of the steps of a reaction

Below we illustrate the four steps for a Megaways slot.

Step 1: it starts with a win

The Avalanche mechanic starts once you have a win, as illustrated below. The green symbols on reels 1 to 4 make a winning combination. The green symbols of reel 6 are not part of the win, as there are no green symbols on reel 5.  

Step 2: the winning symbols disappear, and the remaining symbols drop (tumble)

You see that the green winning symbols on reels 1 to 4 are destroyed and disappear afterwards. This way, empty positions appear, and as a result, the remaining symbols (that were non-winning) drop or tumble downwards. These symbols are called the tumbling symbols or the dropping symbols.

In this example, no symbols drop on reel 4, as no symbols are left on reel 4 (both were winning).

Step 3: empty positions on top of the reels

Once all symbols have tumbled, you see empty positions on the top of the reels.

Step 4: new symbols appear

Afterwards, new symbols appear, such that the playing field (or grid) is complete with symbols.

You have two new symbols on reels 1, 2 and 4 and one new symbol on reel 3. Nothing changed on reels 5 and 6.

Noteworthy is that the total number of symbols remains constant and that the number of Megaways is still intact.


Next steps

If you get another win (after the new symbols show up), the whole reaction starts all over again.

These reactions (and therefore free re-spins) continue till you fail to make a new win. 

Some examples of the avalanche mechanic

Below we have four examples of this feature for some of the most famous slots.

We start (and rightfully so) with Netent’s Gonzo’s Quest, a classic 5×3 slot with 20 paylines. If you win, you gain a free re-spin, and the total win multiplier increases from x1 to x2 to x3 to eventually x5 (after three successive wins).

Almost all grid slots make use of the cascading feature, and below, you see it illustrated for Play’n GO’s Reactoonz 2.

We finish our examples with Big Time Gaming’s Monopoly Megaways.

Below (by coincidence), you see that all reels have seven symbols, making the maximum of 117,649 Megaways.

 Additional features, thanks to the avalanche mechanic

Besides the re-spins, you have more possibilities. With grid slots, for example, you often see that you gain the free spins after 4 or 5 successive reactions.

With Megaways slots (like Gonzo’s Quest), you benefit from an increasing win multiplier after each re-spin. If you win many consecutive times, you have a high multiplier.


Nowadays, we cannot think of a world without the Avalanche mechanic!

The number of possibilities is tremendous, and it’s for the reason that Megaways slots and grid slots thankfully make use of this feature.

You may like

How does a grid slot work?

Megaways slots explained

Win-all-ways slots: how do these work?

Play any of these fantastic slots at these online casinos

If you are looking for any of these spectacular slots, you can check out the reputable online casinos in our list below.

These online casinos offer you the chance to play real money casino games or play with practice money.

Available in your country
  • ⚡️ Multiple cryptocurrencies
  • 🎁 Incredible welcome bonus offer
  • 🚀 Easy-to-navigate platform
Let's roll Review

First deposit bonus is 400% up to €3,000. You must make a minimum qualifying deposit of €25 to claim the NonStop welcome bonus. And once the bonus is added, you must fulfil a 45x wagering requirement within 15 days to keep winnings made from it. Apart from the welcome bonus, NonStop has other offers for existing players. Let’s take a look at some of them.

Bonus info & terms
  • 🚀Large collection of slots
  • 🤑First and second deposit bonus offers
  • ⚡️Crypto payment option
Let's roll Review

For your second deposit, you can claim up to 50% of your deposit, up to €500 and 100 free spins.

Bonus info & terms
  • 🤑 No-deposit bonus
  • 🎁 Generous promotions
  • ⚡️ Progressive jackpots
Let's roll Review

The minimum deposit for the welcome offer is $50, which is a bit higher than most other online casinos I gotta admit. However, if you don’t mind the steep deposit, you can get a pretty decent starting bonus to try out what this casino has to offer.

Bonus info & terms
  • 🤩 7000+ casino games
  • 🎁 Various payment options
  • 🤑 24/7 customer service
Let's roll Review

JackBit Casino does not offer a welcome bonus. Instead, you can benefit from 3+1 freebet offer. Minimum bet is $10 along with 1.3 odd for position.

Bonus info & terms
  • 🤑Three welcome bonuses
  • ⚡️Crypto payments
  • 🤩Players worldwide accepted
Let's roll Review

The welcome bonus can be used on slots and from the following providers: EGT, Play’n GO, Amatic, and NetEnt. Make sure to wager it 45x to be eligible to withdraw your winnings. The bonus will expire in 45 days.

Bonus info & terms
  • 🎁 Multiple bonus offers
  • 🤑 Crypto gaming experience
  • 📱 Mobile compatible site
Let's roll Review

The bonus has a 45x wagering requirement and a minimum and maximum bet of €0.50 and €5. In addition, the bonus is only eligible for games from EGT, Amatic, and NetEnt, and it can’t be used with other promotions. Keep in mind that the 45x wagering requirement can be challenging for newbies.

Bonus info & terms
  • ✅Crypto Casino
  • 🍓300 Free Spins
  • ⚡️Fast Cash-outs
Let's roll Review

Deposit: Does not require a minimum deposit Bonus Match Percentage: 110%, 50%, 75%. Maximum Bonus Value: 1 BTC (and Cryptocurrency equivalent) or 100 EUR (and FIAT equivalent) No Deposit Free Spins: 50 Free Spins Free Spins: 300 Free Spins Free Spins Slot Game: Princess of Sky, Brave Vikings, Book of Pyramids, Cherry Fiesta, Desert Treasure, Lucky Lady Clover, West Town, Lucky Blue, Princess Royal, Hawaii Cocktails Bonus Wagering: 35 x Bonus Free Spins Wagering: 40 x Free Spins Remarks: 250 Free Spins offered as part of the 1st Deposit Bonus will be rewarded in a set of 50 spins for 5 days. Minimum deposit required for the spins is 0.05 BTC (and Cryptocurrency equivalent) or 50 EUR (and FIAT equivalent). Full T&C Apply. 18+

Bonus info & terms
  • 🎁 Juicy Welcome Bonus
  • 🔥Various Slots
Let's roll Review

Select the Welcome Casino Bonus option from the menu drop-down and deposit at least €25 to qualify for this offer.

Bonus info & terms
  • ✅Bitcoin Casino
  • 🎁Gigantic Welcome Bonus
  • ❤️Excellent Customer Support
Let's roll Review

Bonus Code: MAX300 Deposit: Minimum required deposit is $20 Bonus Match Percentage: 300% Maximum Bonus Value: $3000 Free Spins: 200 Free Spins over 10 days Free Spins Slot Game: N/A Bonus Wagering: 40 x Bonus + Deposit Free Spins Wagering: 35 x Free Spins Remarks: Slots, Keno & Scratch Cards only to fulfil wagering requirement. The max cash out from free spins is $200. Full T&C apply. 18+

Bonus info & terms
  • 🍒 1,000+ slots
  • 🤩 VIP Club
  • 📱 Mobile-Friendly
Let's roll Review

The wagering requirements on all deposit bonuses are quite decent: 40 x the bonus amount. Don’t forget: If you want to avoid these bonus wagering requirements, you can always choose to decline any bonus. The max bet per spin with bonus money is unusually high at $15 per spin.

Bonus info & terms