Free Spins in Slots: How the Bonus Feature Works
Free Spins are one of the most familiar bonus features in slots, and they’ve changed more than most since I started in 2005.
Developers keep finding different ways to use them. This guide is about the Free Spins built into a game’s rules, not the free spins offers advertised by casinos. The names are the same, but they’re different things.
Quick answerIn-game Free Spins are bonus spins awarded under a slot’s rules without an additional stake for each spin. The trigger, starting count, feature changes and ending conditions depend on the game.
What are Free Spins in slots?
A Free Spins round can look much like the base game, or it can change the reels, the symbols and the way wins are worked out.
Book of Hidden Tombs is the familiar pattern: three or more Book symbols trigger 10 Free Spins, one non-Scatter symbol is picked at random as the Golden Expanding symbol, and three or more Books during the feature add another 10 spins. The Dog House shows how quickly that picture changes: before its feature begins, a grid decides whether you get anywhere from 9 to 27 spins.
How do in-game Free Spins work?
Buffalo King is 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 handles the spin count quite differently. You start with three spins, but every winning spin resets the counter to three, and the feature only ends after three losing spins in a row. There’s a counter on screen, but nobody knows the total when the round begins.
Compare Free Spins between games
Pick any two games to compare how their Free Spins start, what changes during them and how they end.
Compare how two games award Free Spins, what changes during them and what keeps the bonus running. Free Spins are extra game spins played without another stake. The number awarded, the rules during the round and the ways it can continue differ from game to game. Some have a fixed counter, while others use collections, stages or a resetting spin counter. Sources: Pragmatic Play in-game rules; Pragmatic Play game overview Sources: Hacksaw Gaming in-game rulesCompare Free Spins in two slots
At a glance
The Dog House Chaos Crew How do the spins start?
Three Bonus symbols on reels 1, 3 and 5 lead to a 3x3 randomiser. Its nine values add up to 9 to 27 Free Spins.
Three Free Spins symbols start the feature with three remaining spins, rather than a fixed total for the entire round. What changes during them?
Wilds on reels 2 to 4 become sticky, keeping their 2x or 3x multipliers for the rest of the feature.
Each reel has a value above it. Cranky and Sketchy symbols raise or multiply those values during the feature, and their combined total is awarded at the end. How do they continue or end?
The bonus cannot retrigger: Bonus symbols are absent during Free Spins. The round ends after the awarded spins.
Each non-winning spin uses one of the remaining spins. Three consecutive non-winning spins end the feature. See how Free Spins rules differ
The Dog House
Free Spins featureRandom starting spinsFree Spins
Chaos Crew
Free Spins featureThree-spin reset counterFree Spins
How does a Free Spins feature start?
Scatter symbols are the usual trigger, but not the only one. 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 for 15 Super Free Spins. At the start, you pick one of two hidden options, which reveals whether you get the Storm or Thunder version.
How many Free Spins are awarded?
The starting count can be fixed, determined by the trigger, randomised before play or kept open by a reset rule.
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, line wins are doubled and any Wild that lands stays put.
Gonzo’s Quest uses NetEnt’s name Free Falls. One triggering line awards 10 Free Falls; two lines award 20.
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, above, is the clearest case: its counter keeps resetting, so there is no total to award.
Can Free Spins be retriggered?
Often, but not always, and not always by landing the same symbols again.
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.
What can change during Free Spins?
The bonus can also alter the reels, the Wilds or the way values carry forward from one spin to the next.
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 Cash Collect 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.
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 is a clear example. 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. The same marked cells therefore have a longer lifetime in the bonus.
Gates of Olympus uses another form of persistence. Qualifying multiplier values can build a running total across the Free Spins feature. That total isn’t applied to every later win, though: it multiplies a winning spin only when a multiplier symbol is on screen.
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.
Free Spins, Super Free Spins and upgraded modes
“Super Free Spins” sounds like a standard term. It isn’t: each game decides what makes its version super.
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.
How do Free Spins end?
Most rounds end when the counter reaches zero. Not all of them.
Chaos Crew ends after three losing spins in a row. Big Bass Bonanza can end early if its 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.
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 means choosing between known feature options. Thor’s Rage 2 looks like a choice but isn’t one: you pick a hidden option, and it reveals Storm or Thunder. With a real Bonus Selection, you know what you’re choosing. The resulting round is still a Free Spins feature.
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 FAQ
Can you buy Free Spins?
Some games sell direct entry to their bonus round, usually called Feature Buy or Bonus Buy. It’s not available in games offered by GB-licensed operators. See the Feature Buy guide for why UK versions differ.
Do Free Spins change a game’s RTP?
A game’s stated theoretical RTP includes the effects of its bonus features, including Free Spins, under the applicable game configuration. Triggering the feature does not by itself change that published overall figure. Different game versions or configurations can have different RTPs, so the presence of Free Spins alone tells you nothing reliable about a game’s return.
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
Where this guide comes from
Every example here is checked against the game’s own rules and the developer’s material.