Free Spins in Slots: How the Bonus Feature Works
Free Spins sound straightforward: the game awards a sequence of spins and you do not place a fresh stake for each one. That is the easy part. What happens after the feature starts varies much more. Some games change the reels, some make Wilds sticky, some carry multipliers from one spin to the next, and some do not even have a fixed total number of spins at the outset.
Quick answerIn-game Free Spins are a bonus feature that awards a sequence of full game spins without an additional stake. The sequence begins with a game-defined starting count or continuation rule, may use different reels, symbols or persistent modifiers, and ends under the game’s own termination rule.
What are Free Spins in slots?
In-game Free Spins are a bonus feature in which the slot gives you a sequence of spins without a fresh stake for each awarded spin. The round can look much like the base game, or it can change the reels, symbols and other mechanics substantially.
Book of Hidden Tombs shows the familiar pattern: three or more Book symbols trigger 10 Free Spins, one non-Scatter symbol is chosen as the Golden Expanding symbol, and three or more Books during the feature add another 10 spins. The Dog House shows how quickly that simple picture starts to vary. Its starting award is randomised between 9 and 27 spins before the feature begins, and its Sticky Wild multipliers remain in place for the rest of the round.
The core ideaFree Spins define the awarded-spin sequence. The trigger, starting count, retrigger rule and any changes to the reels or symbols belong to the individual game.
In-game Free Spins vs casino promotional free spins
This page is about the feature built into the slot itself. When its trigger or entry rule is met, the game moves into the Free Spins round and plays the awarded sequence under that feature’s rules.
Casino or operator promotions that are also called “free spins” are different. They are account-level promotional offers, not part of the game’s internal feature logic. They may use the same words, but they are not the mechanic Slotathon classifies as Free Spins.
The shared wording is the confusing bit: a promotional offer tells you nothing about how the in-game Free Spins feature actually works.
How do in-game Free Spins work?
The quickest way to make sense of a Free Spins feature is to follow six questions: what starts the round, what determines the starting count, what changes once it begins, what carries from one spin to the next, what can add or upgrade spins, and what finally ends the feature.
Buffalo King shows the familiar version. Three, four, five or six Bonus symbols award 8, 15, 25 or 100 Free Spins. During the feature, Wilds can carry random 2x, 3x or 5x multipliers, and Bonus symbols can add more spins, again depending on how many land.
Chaos Crew works differently. It starts with three remaining spins, but a qualifying win resets that counter to three. The feature ends only after three consecutive non-winning spins. So although the game displays a spin counter, the total number of spins is not fixed when the feature begins.
How does a Free Spins feature start?
Scatter symbols are a common trigger, but they are not part of the definition. Different games use different entry conditions.
Eye of Horus uses three or more Scatters to trigger its Free Games. The Dog House uses three Bonus symbols on reels 1, 3 and 5. Chaos Crew uses three Free Spins symbols. Thor’s Rage 2 uses four Scatters for 15 Free Spins or five Scatters for 15 Super Free Spins, followed by a choice between its Storm and Thunder bonus paths.
So “land three Scatters” describes many Free Spins features, but it is not the rule.
How many Free Spins are awarded?
There is no standard number. The starting award can be fixed, depend on the trigger, be randomised before the round, or be governed by a continuation rule instead of a predetermined total.
Fixed awards
Book of Dead starts with 10 Free Spins when three or more Book symbols trigger the feature. Book of Hidden Tombs also starts its standard feature with 10 Free Spins. Thor’s Rage 2 starts either its regular or Super version with 15 spins. Legacy of Dead starts with 8 Free Spins when three or more Scatter symbols trigger the feature.
Dead or Alive starts with 12 Free Spins when three or more Scatters trigger the feature. During those spins, bet-line wins are doubled x2 and landed Wilds become sticky.
Gonzo’s Quest uses NetEnt’s name Free Falls. One qualifying trigger line awards 10 Free Falls, while the Game Sheet awards 20 when the triggering condition occurs on two paylines.
Trigger-dependent awards
Buffalo King ranges from 8 to 100 starting Free Spins depending on whether three, four, five or six Bonus symbols trigger the round. Sugar Rush awards 10, 12, 15, 20 or 30 spins for three through seven Scatters.
Randomised or adjusted starting counts
The Dog House uses a 3×3 pre-feature grid in which nine cells each reveal one, two or three spins. Their total becomes the starting award, producing 9 to 27 Free Spins. Raging Rhino Double Danger starts its optional Free Spins Gamble from 15 spins: a winning gamble adds five and can be followed by another gamble, while a losing gamble removes five and starts the feature. The resulting starting range is 10 to 30 spins.
When the total is not fixed in advance
Chaos Crew has no predetermined total: qualifying wins restore its three-spin counter, so the round can continue beyond the opening three spins.
Can Free Spins be retriggered?
Often, but not always. A retrigger or extension adds more spins after the feature has started, but what causes it varies by game.
Buffalo King uses more Bonus symbols, with the number landed deciding how many additional spins are awarded. Book of Hidden Tombs awards another 10 Free Spins when three or more Books land during the feature. Eye of Horus does something different again: one, two or three Horus Wilds award one, three or five additional Free Games.
Big Bass Bonanza separates the extension rule from its Scatter trigger. The 4th, 8th and 12th collected Fisherman Wilds each award 10 extra Free Spins, and those retriggered spins are queued to play after the current batch.
Retriggers are not universal. In The Dog House, Bonus symbols are absent from the Free Spins reels and the feature cannot retrigger.
No universal retrigger ruleA retrigger might use the original trigger symbols, a Wild count, a collection threshold or another game-specific condition. Some Free Spins features do not allow retriggers at all.
What can change during Free Spins?
Sometimes very little changes beyond the spin counter. In other games, Free Spins are where the slot changes gear.
Reels and symbol sets
The Dog House removes its Bonus symbols from the feature reels. Wolf Gold changes the middle of the screen so reels 2, 3 and 4 spin together as one 3×3 Giant Symbol.
Wilds and multipliers
Buffalo King gives each Free Spins Wild a random 2x, 3x or 5x multiplier. In The Dog House, Wilds landing on reels 2 to 4 become Sticky Wilds and keep their assigned 2x or 3x multiplier through the rest of the feature. Raging Rhino Double Danger uses 2x, 3x and 5x Wilds in Stampede Free Spins.
Collection and progression
Big Bass Bonanza combines Free Spins with Money Collection and Symbol Collection. Fisherman Wilds collect visible Money values while the accumulated Fisherman count separately drives retriggers and collection-multiplier progression.
Razor Shark changes the Mystery-symbol behaviour instead. During Free Games, reels 2 and 4 fill with Mystery symbols that nudge down one position with each spin, and every nudge increases the feature multiplier.
The important point is that Free Spins provide the round in which those other mechanics operate. Collection, multiplier, Wild and symbol behaviour still have their own rules.
What can carry from one Free Spin to the next?
Some changes last for one spin. Others become part of the feature until it ends.
Sugar Rush makes that distinction unusually clear. In the base game, marked multiplier cells persist only through the current tumble sequence. During Free Spins, those same marked cells and multiplier values remain active across later spins and can keep increasing. In other words, the bonus makes those multipliers last beyond a single tumble sequence.
Gates of Olympus uses another form of persistence. Qualifying multiplier values can build a running total across the Free Spins feature. That stored total is not automatically applied to every later winning spin, however – the reviewed rules show a separate application condition when a qualifying multiplier symbol is present.
The Dog House uses persistence in a different way. Once a qualifying Wild lands, its reel position and 2x or 3x multiplier stay fixed until the final Free Spin.
That sort of carry-over appears in several games Slotathon has reviewed, but it is not part of the definition. A Free Spins feature can change symbol or modifier rules without carrying a growing state from one spin to the next.
Free Spins, Super Free Spins and upgraded modes
“Super Free Spins” sounds as though it should mean the same thing everywhere. It does not. The rules are game-specific.
In Thor’s Rage 2, five Scatters trigger 15 Super Free Spins instead of the regular version. During ordinary Free Spins, four Scatters add five spins and upgrade the remaining spins to Super Spins. Once Super Spins are active, Scatters can no longer land.
Book of Hidden Tombs has its own Super Free Spins route tied to Golden Scatters and a Scatter Collector. It is still a Free Spins round, but the Super version adds a progressive multiplier.
So “Super” tells you that the game has an enhanced bonus state. It does not tell you which symbols change, how the upgrade happens or whether the enhanced version can retrigger.
How do Free Spins end?
In many of the games Slotathon has reviewed, the feature ends when the remaining awarded spins are played and the counter reaches zero. That is not the only way a Free Spins round can finish.
Chaos Crew ends after three consecutive non-winning spins rather than after a fixed total award. Big Bass Bonanza can end early if its documented 2,100x maximum-win cap is reached, with remaining Free Spins forfeited. Sugar Rush likewise ends immediately if its 5,000x cap is reached.
In The Dog House, the Sticky Wild state lasts until the final awarded spin. In Sugar Rush, marked multiplier-cell state clears when the Free Spins feature ends. Other games handle the reset differently, so that part has to be checked game by game.
Free Spins vs other bonus mechanics
Free Spins vs Hold & Win / Money Respins
Money Respins hold qualifying prize-bearing symbols in place while the remaining positions respin under a finite continuation rule. Free Spins are an awarded sequence of full game spins. The two can coexist: Wolf Gold allows its Money Respin feature to trigger during Free Spins.
Free Spins vs Bonus Feature Selection
Bonus Feature Selection is about choosing between feature paths or variants. Thor’s Rage 2 makes the difference clear: choosing Storm or Thunder determines the bonus path, while the spins that follow are still the Free Spins round.
Free Spins vs Feature Buy / Paid Bonus Access
Feature Buy changes how a player enters a bonus where that option is available. It is not part of the Free Spins definition. Availability is game- and jurisdiction-specific, so the presence of Free Spins does not mean a buy option exists.
Free Spins examples compared
| Game | Starting structure | What changes | Extension / end rule |
|---|---|---|---|
| Buffalo King | 8/15/25/100 spins from 3/4/5/6 Bonus symbols. | Wilds carry random 2x/3x/5x multipliers. | Bonus symbols can add 5 to 100 more spins depending on count; feature ends when awarded spins are used. |
| Big Bass Bonanza | 10/15/20 spins from 3/4/5 Scatters. | Fisherman collection, feature progression and collection multipliers. | Every fourth Fisherman adds 10 spins, up to three times; 2,100x cap can end the round early. |
| The Dog House | Randomised 9 to 27 spins from a 3×3 pre-feature grid. | Wilds on reels 2-4 become sticky with persistent 2x/3x multipliers. | No retrigger; ends when the randomised count reaches zero. |
| Chaos Crew | Starts with 3 remaining spins. | Feature runs under a resetting continuation counter. | A win resets the counter to 3; three consecutive non-winning spins end the feature. |
| Sugar Rush | 10/12/15/20/30 spins from 3-7 Scatters. | Multiplier cells persist across the whole feature. | The same Scatter counts add the same quantities; 5,000x cap can end the feature early. |
| Book of Hidden Tombs | 10 spins from 3+ Books. | A Golden Expanding symbol is selected; an enhanced Super Free Spins mode also exists. | 3+ Books add 10 more spins in the standard feature. |
| Eye of Horus | Free Games triggered by 3+ Scatters. | Horus Wilds drive symbol upgrades during the feature. | 1/2/3 Horus Wilds add 1/3/5 Free Games. |
| Thor’s Rage 2 | 15 Free Spins from 4 Scatters or 15 Super Free Spins from 5. | Storm/Thunder path and possible upgrade to Super state. | 3 Scatters add 5 spins; 4 add 5 and upgrade remaining regular spins to Super Spins. |
| Raging Rhino Double Danger | Optional Free Spins Gamble starts from 15; the permitted starting range is 10-30 spins. | 2x, 3x and 5x Wilds. | 2/3/4 Bonus symbols add 5/10/15 spins; total retriggered spins are uncapped. |
What the Free Spins label does not tell you
Knowing that a slot has Free Spins does not tell you how the feature triggers, how many spins it starts with, whether it can retrigger, whether the reels change, which symbols appear, whether modifiers persist, or whether an upgraded version such as Super Free Spins exists.
It also tells you nothing by itself about RTP, volatility, hit frequency, Free Spins frequency, maximum win or the likelihood of winning. Those are separate game properties that need their own evidence.
Likewise, the presence of Free Spins does not mean the feature can be bought directly, that an Ante Bet is available, or that either option is permitted in a particular jurisdiction.
Free Spins FAQ
What are Free Spins in slots?
They are an in-game bonus feature that awards a sequence of game spins without an additional stake for each awarded spin. The starting count or continuation rule and any feature-specific changes are set by the individual game.
How do Free Spins work in slots?
The game enters a bonus state, starts with a defined spin count or continuation rule, applies any feature-specific reel, symbol or modifier changes, and continues until the game’s termination condition is reached.
Are in-game Free Spins the same as casino promotional free spins?
No. In-game Free Spins are a game mechanic. Casino promotional free spins are account-level promotional offers and do not define how a slot’s internal bonus feature behaves.
How are Free Spins triggered in slot games?
The trigger is game-specific. In the games Slotathon has reviewed, examples include Scatter symbols, Bonus symbols, dedicated Free Spins symbols and other bonus-entry rules.
Do all Free Spins use Scatter symbols?
No. Scatters are common, but The Dog House uses Bonus symbols and Chaos Crew uses dedicated Free Spins symbols. Trigger symbols and positions have to be checked game by game.
How many Free Spins are awarded?
There is no standard number. A game may award a fixed count, vary the count with the trigger, randomise it before the feature, alter it through a pre-feature rule, or use a continuation counter instead of a fixed total.
Can Free Spins be retriggered?
Some can and some cannot. Buffalo King, Book of Hidden Tombs, Eye of Horus and Big Bass Bonanza all add spins under different rules, while The Dog House explicitly cannot retrigger.
Do all Free Spins retrigger the same way?
No. Extra spins can be tied to the original trigger symbols, a Wild count, a collection threshold or another game-specific condition, and the number of added spins can also vary.
What can change during Free Spins?
The game may change reels, symbol sets, Wild behaviour, multiplier rules, collection features, grid or reel state, or how long another mechanic remains active. None of those changes is universal.
Can multipliers, Wilds or other modifiers persist between Free Spins?
Yes, where the rules specify it. The Dog House keeps Sticky Wild positions and multipliers for the rest of the feature, while Sugar Rush keeps marked multiplier cells active across later Free Spins.
Do Free Spins use different reels or symbol sets?
They can. The Dog House removes Bonus symbols during the feature and Wolf Gold changes the middle reels into a 3×3 Giant Symbol. Other games may retain more of the base-game setup.
What are Super Free Spins?
They are a game-specific enhanced Free Spins mode, not one universal mechanic. Thor’s Rage 2 and Book of Hidden Tombs both use enhanced versions, but their upgrade rules and feature changes are different.
Can Free Spins be bought directly?
Some games offer paid bonus access in permitted configurations, but Feature Buy is a separate access mechanic. Its availability is game- and jurisdiction-specific and is not part of the Free Spins definition.
How do Free Spins end?
Most reviewed features end when their remaining awarded spins are exhausted, but exceptions exist. Chaos Crew ends after three consecutive non-winning spins, and some games terminate early when a documented maximum-win cap is reached.
Do Free Spins change RTP or the chance of winning?
The presence of Free Spins does not establish anything by itself about RTP, volatility, hit frequency, Free Spins frequency, maximum win or the likelihood of winning. Those properties need separate evidence for the game and configuration being discussed.
Sources reviewed
The examples on this page were checked against primary material wherever possible. Linked game names below lead to the software provider’s public game page where available. The evidence reviewed may also include in-game rules, developer game sheets, certification documents and authenticated developer material that is not publicly accessible.
Pragmatic Play
Pragmatic Play / Reel Kingdom
Hacksaw Gaming
BGaming
Blueprint Gaming
Red Tiger
Atlantic Digital / Light & Wonder
How we research slot mechanics
Slotathon starts with primary evidence such as game rules, in-game help, developer documentation and game sheets. Published mechanic claims are based on the strongest available primary evidence.
When primary sources differ, we keep those distinctions visible in the research rather than quietly forcing them into one version.