Cascades, tumbles and avalanches: how one spin becomes a chain of wins

Following a single spin through Figure 1

First the spin lands and is checked under the game’s pay system: lines, ways or groups (how slots pay sets them out). In Figure 1 the only payline is the middle row, so the three A symbols there make payout 1, worth 0.5x the total bet, and the three K symbols on the top row pay nothing. The studio pages quoted here say “win” for a paying combination of any size; this guide says payout, because a payout can be smaller than the stake.

Next, the paying symbols go, or as Habanero puts it for Hey Sushi, “Winning symbols are replaced with new symbols.” Then the gaps fill and the game looks again. NetEnt’s page for Gonzo’s Quest, a payline game, has both moves: “When you form a winning combination of symbols on a payline, the icons explode, and their empty spaces are filled with new symbols cascading down the screen like tumbling rocks.” In the third frame the K symbols have dropped onto the payline for payout 2, worth 0.3x, and the running total is 0.8x. New symbols, drawn dashed, fill the three gaps in the top row with Q 9 J. When the K symbols go in turn, the Q 9 J above them drops onto the payline, which then reads Q 9 J 10 Q. That pays nothing, so the chain stops after two payouts.

Nothing new is staked between the steps. No studio says so outright, so this is our reading. NetEnt’s page for Gonzo’s Quest II: Return to El Dorado does write of “all Avalanches for a spin” in its Free Spins section, and none of the pages quoted here mentions a further stake partway through a chain.

When the chain stops, and why it is still one spin

Pragmatic Play gives a plain stopping rule for Sugar Rush 1000: “A tumble feature sees these groupings removed from play, with empty positions being filled from above until no more wins appear as part of that sequence.” NetEnt ties Gonzo’s Quest II’s Expanding Reels feature to the same point: “In the base game, the feature ends when no more Avalanches happen, and the reels reset to the original 6-reel, 4-row setup for the next spin.”

The clauses below are written for money play; here the stake and the balance are virtual credits. GLI-19, the testing standard introduced in the paytable guide, may be adopted in whole or in part by any regulator (1.3.3). Its game cycle runs from one wager to the next (4.3.3(a), glossary) and ends once the stake is lost or the last award is credited to the balance (4.3.3(d)). A new game cannot start before then, barring an orderly end to the current one or a granted exception (4.3.3(e)).

In Great Britain, compliance with the Gambling Commission’s remote technical standards (RTS) is a licence condition for the remote gambling and gambling software businesses it licenses. Guidance to RTS 14D runs a game cycle from the start press until everything staked or won has been lost or made available and the start button works again. A 2021 consultation response adds that feature or bonus rounds awarded from the base game belong to the same cycle when no extra funds are wagered.

Neither text names cascades, tumbles or avalanches, but on both definitions a chain plays out before the next spin can start, so it belongs to the spin that set it off. That is our reading, not a ruling; no GLI-19 or Commission text we read deals with it.

South Africa’s National Gambling Board says “gambling machines and devices” must meet SANS 1718 and be tested by licensed, SANAS-accredited laboratories; its page does not mention online games (see what South Africa’s testing rules cover). We have not read SANS 1718, which is not freely published, and no South African text we read deals with cascades or game cycles. GLI-19 and the British standards are not South African law.

Cascading reels, tumbles, avalanches: what the studios’ pages call it

None of the studio pages quoted here says “cascading reels”. Where a page names the feature, it uses its own word. Pragmatic Play’s page for another of its games talks of “tumbling reels”.

The third column shows the feature on lines, ways, connected groups and pay-anywhere grids, and in Techno Tumble with no reels at all.

Where the new symbols come from

Which symbols fill a gap, and from where? On Gates of Olympus 1000, “a tumble feature sees winning combinations removed from play, being replaced by new icons which fall from the top of the gameboard”. On Sugar Rush 1000, too, empty positions are “filled from above”.

Moon Princess keeps the drop within each column: “Symbols in winning combos disappear, allowing symbols in the same column to drop into place”. Not every winning position simply empties, though: “The Wild Moon may appear in place of the middle symbol in a winning combo”.

Habanero describes Techno Tumble by physics: “15 - 45 symbols tumble into the game zone by way of physics.” The page does not say whether only the winning symbols leave, or how a gap is filled.

In Gonzo’s Quest II the chain changes the grid’s shape: “Each Avalanche adds one row to the top, up to a maximum of 4 extra rows.” In the base game, the reels then reset to four rows for the next spin. On Moon Princess, clearing all 25 symbols sets off a feature of its own, a series of free spins “with an ever-increasing multiplier”.

Multipliers along the chain

Several of the games above attach a multiplier to the chain. GLI-19 asks a game to show any change in award value during play and to state the criteria for it (4.4.1(g)); on our reading, a multiplier climbing during a chain is such a change. What a multiplier applies to is in step 4 of the paytable guide; here the question is when it changes.

Steps that climb as the chain goes on

Habanero’s page for Hey Sushi says that “Each cascade increases the multiplier” and lists the steps: “Base Game multipliers are x1 x2 x3 x5.” For the main game of Gonzo’s Quest, NetEnt gives a step and a ceiling, “Each Avalanche™ action increases the Win Multiplier by 1, up to a maximum of 5x”, and adds that “A non-winning spin resets the Win Multiplier progress”.

On multipliers, Habanero’s overview of Techno Tumble has one sentence: “Additional cascading rounds with increased multipliers are awarded for winning games.” Play’n GO says the Moon Princess multiplier rises each time new symbols drop. Neither description gives the steps, or says how far the multiplier climbs in the base game.

A made-up case, tied to no studio: if Figure 1’s game applied a multiplier of x1 to its first payout and x2 to its second, payout 2 would double from 0.3x to 0.6x. The spin would then return 0.5x + 0.6x = 1.1x the total bet.

Values gathered during the chain and applied at the end

In a made-up game whose rules add its multipliers, an x2 and an x5 on screen when the chain ends combine into one x7 multiplier for the chain’s total payout; multiplied, they would make x10. Both Pragmatic Play games below hold their values back until the chain ends.

On Gates of Olympus 1000 the multiplier symbols “can hit randomly during both spins and tumbles”, and their values wait: they are “combined at the end of a tumble sequence and applied to the player’s win”. Pragmatic does not say how they are combined. The game’s free spins keep a total for the round instead, a pattern covered in the same paytable step.

Pragmatic’s list for Sweet Bonanza 2500 puts its candy bomb multipliers in the bonus game, where they wait in a similar way: “Multipliers remain on screen during tumbles before being added together and applied to the total win.”

What resets after a spin, and what lasts the round

On Sugar Rush 1000 the multiplier belongs to a square: “Whenever a winning symbol explodes, its spot is marked on the grid. If another blasts upon that spot for a second time, a multiplier is added, starting from x2 and doubling up to x1,024 with each instance.” It is then “added to all winning combinations that are formed on top of it”. In free spins, “marked spots and their multipliers will remain in place until the round ends”. For base-game spins, the page does not say.

In the Free Spins mode of Gonzo’s Quest II, the global multiplier “starts at x2 and increases by 2 with each Avalanche” and goes back to x2 for the next spin. New rows, by contrast, “remain in place for the next spin, up to a maximum height of 8 rows”. On entering free spins, NetEnt writes, “Any expanded reels or increased multipliers from the main game do not carry over.”

The studio pages leave open where the Gonzo’s Quest ladder starts, which payout each step of a ladder applies to, and what happens if a cap on a multiplier or on the spin’s total is reached partway through a chain. Look for those in a game’s own rules, with what resets after each spin and what lasts the round; step 5 of the paytable guide lists the questions to ask of any feature.

Adding up the spin

In Figure 1’s made-up game the payouts in the chain are added up, and that total is what the spin returns. Set against the stake, 1x in the figure, 0.5x + 0.3x = 0.8x comes back: 0.2x less than was staked, although the spin paid twice. Each payout is the paytable’s value for its combination, which can be below the stake (step 1 of the paytable guide reads such a row), so a chain of small payouts can add up to less than the stake.

For the last completed game, GLI-19 asks that the outcome and the amount won be shown (4.3.4(e)). We take that to cover the whole chain.

Britain’s RTS 14F bars a game from celebrating a return no bigger than the total stake, and its guidance defines celebrating as using the sounds or visual effects associated with a win. The guidance also lists ways to tell the player the result of their game cycle: a display of the total amount awarded, winning lines shown briefly, a brief sound.

The Commission said it had not consulted on banning returns at or below the stake, only on the celebration, so that a net losing spin can be told from a net winning one. It gave two reasons. One was fairness: players should be able to tell whether an outcome returned more than their total stake. The other was that signalling wins more often than they occur could bring on a state associated with gambling-related harm (our responsible gambling page lists help in South Africa).

Applying this to cascades is our step, not one taken in any Commission text we read. If that step holds, a chain whose payouts add up to the stake or less is not a true win in the Commission’s sense, so under RTS 14F it may not be celebrated. The volatility guide covers losses disguised as wins.

Do the chains pay on top of a game’s return? Pragmatic calls the tumble a feature on its Gates of Olympus 1000 and Sugar Rush 1000 pages, and where a return to player (RTP) figure is shown, GLI-19 asks that the contribution of features to it be disclosed (4.7.2(c); step 6 of the paytable guide). Our reading is that a chain’s payouts are part of the published RTP, not extra to it.

Where a game’s cascade rules are written

For the full rules of a game’s cascades, look in its own help or rules pages; the paytable guide shows how to read them. Every demo on this site runs on virtual credits: nothing is deposited and nothing is paid out, and a demo is not practice for playing with money.

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If gambling has stopped being fun for you or someone close to you, the responsible gambling page lists where to find help in South Africa.

Sources

Quotes were matched to the pages below on 29 October 2026. The rules screens inside a game may phrase a rule differently, or say more.

• NetEnt game pages for Gonzo’s Quest and Gonzo’s Quest II: Return to El Dorado.
• Pragmatic Play game pages for Gates of Olympus 1000, Sugar Rush 1000 and Sweet Bonanza 2500, and the Gates of Olympus page for the phrase “tumbling reels”.
• Habanero game pages for Hey Sushi and Techno Tumble.
• Play’n GO: the Moon Princess game page.
• Gaming Laboratories International, GLI-19 Standards for Interactive Gaming Systems, version 3.0, revised 17 July 2020: sections 1.3.3, 4.3.3, 4.3.4, 4.4.1 and 4.7.2, and the glossary.
• UK Gambling Commission: About us; Remote gambling and software technical standards: the introduction and RTS 14, responsible product design.
• UK Gambling Commission, consultation response Online games design and reverse withdrawals, and its summaries of responses on introducing speed of play limits and on prohibiting effects that give the illusion of false wins.
• National Gambling Board, Technical Standards (SABS).