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Prairie Thunder: a free Bison Fury alternative

Built like Bison Fury: five reels, four rows, 1,024 ways, free spins where wilds hold and respin, and a jackpot wheel that starts at random. Played with chips that are worth nothing, with the machine's real numbers and a session coach beside it.

  • Stampede80,000
  • Supercell10,000
  • Tempest2,000
  • Squall800
  • Breeze320

Play chips

4,000

Bet

40

Win

0

Pick a bet and spin. All 1,024 ways play on every spin.

1,024 ways for 40 coins at 1 a coin. No real money, no prizes, nothing to buy.

Session coach

Last round

Nothing played yet. After each of your spins the coach says what the round cost and what decided it.

Decide the cost before you start

Gambling is entertainment with a price, like a concert ticket. The useful question is not how much you might win but how much the evening is allowed to cost. Pick that number first, and treat reaching it as the end of the session. You can set one below and the coach will hold you to it.

Next bet

40 chips at a 4.08% house edge: an expected cost of 1.6 chips.

This table is for practice and entertainment only. How to keep gambling safe

What the ways pay

What one way of three, four and five of each symbol pays in chips at a bet of 40
Symbol345
Bison40100250
Pronghorn3070180
Coyote2255120
Meadowlark1845100
Ace123075
King123075
Queen61860
Jack61860
Ten51240
Nine51240

Chips paid for one way at a bet of 40. A symbol pays for three, four or five reels in a row from the first reel, times the number of ways it was made: its count on each of those reels, multiplied together. The dimmer figures are smaller than the bet, so a win of one way at those costs more than it returns.

  • The Thunderhead is wild on reels 2, 3 and 4 and pays nothing of its own. In the free spins each one holds for 1 to 5 respins, each number equally likely, and respins are extra.
  • The Windmill pays nothing. 3 in view give 8, 4 in view give 20, 5 in view give 50 free spins, in the free spins too, up to 200 in one feature.

The jackpot wheel

The five jackpot prizes at a bet of 40, each one's share of the wheel and its odds on any one spin
PrizeChipsWheelAny spin
Stampede80,0000.5%1 in 200,000
Supercell10,0002.5%1 in 40,000
Tempest2,00012.0%1 in 8,333
Squall80030.0%1 in 3,333
Breeze32055.0%1 in 1,818

The wheel starts on 1 paid spin in 1,000, at random, at every bet. The reels have no say in it and no spin is closer to it than any other. The prizes are fixed multiples of the bet. There is no pooled prize here, because play chips have no pool to feed. The reels pay at most 10,000 times the bet in one round.

What this machine costs

Return to player
95.92%
The machine keeps 4.08%
Expected cost of a spin
−1.63
At a bet of 40
Spins that pay anything
23.7%
11.2% pay less than the bet
Spins that gain chips
11.9%
Free spins on 1 spin in 60
Return from the paid spin
59.4%
Counted from the strips
Return from free spins
33.3%
Jackpot 3.3%

The paid spin's return and the odds of the free spins are counted from the reel strips, and the jackpot is arithmetic. The free spins and the hit rates are simulated over 200,000,000 rounds of this machine. See what a return like this does to a bankroll over a session

This session

Spins
0
Chips staked
0
Net chips
0
Expected at this return
0
Spins that paid
0
Paid less than the bet
0
Free spin features
0
Jackpot wheels
0

The machine lights up for every paying spin. The count of spins that paid less than the bet is how many of those left you with fewer chips than before.

Built by Alexander Korsager · last updated October 3, 2026 · corrections

Of the chips bet, paid back over the long run
95.92%
Ways in play on every spin
1,024
Of all spins, the share that pay nothing
76.3%
Of the spins that pay, the share that pay less than they cost
47%

01 / 03

Held wilds and a wheel that starts at random

Prairie Thunder is a free Bison Fury alternative: our own slot machine, built to play the way Entain's Bison Fury plays.

Five reels, four rows and 1,024 ways that pay from the first reel. A wild on the three middle reels. A scatter that pays nothing and starts 8, 20 or 50 free spins, where every wild that lands holds its place for 1 to 5 respins. And a jackpot that no symbol triggers: any spin can start the wheel, at random. If you came looking for a free game like Bison Fury, this is that mechanic. The name, the art, the sound, the reel strips and the pay table are ours. It is not Bison Fury, and it is not made, licensed or endorsed by Entain.

Wilds that hold, and the respins each has left

A free spin lands

The first respin

Each wild is given a number from 1 to 5, every one equally likely. It keeps its place while every other position spins again, the number drops by one, and at nothing left it lets go. A respin is extra: it does not use up a free spin.

One thing is necessarily different.

Bison Fury's jackpot is a pooled progressive, fed by a share of every bet. Play chips have no pool to feed, so the wheel here pays five fixed prizes, each a multiple of the bet, and the chance of the wheel is the same at every bet size.

The wheel, laid flat at its true size
PrizePaysOf the wheelPaid spins
Breeze8x55.0%1 in 1,818
Squall20x30.0%1 in 3,333
Tempest50x12.0%1 in 8,333
Supercell250x2.5%1 in 40,000
Stampede2,000x0.5%1 in 200,000

Fixed multiples of the bet, with no pool behind them. Any paid spin starts the wheel 1 time in 1,000, at every bet, and once it starts it pays 32.65 bets on average.

What a real machine leaves out is on this page.

Prairie Thunder returns 95.92% of the chips bet on it and keeps 4.08%. 76.3% of spins pay nothing. Of the 23.7% that pay, 47% pay less than the spin cost, so only 11.9% of spins leave you with more chips than before. The machine lights up for all of them. The status line under the reels and the coach beside them tell you which kind you just had.

One hundred spins, sorted by result
pay nothing
76.3%
pay less than the spin cost: a loss
11.2%
pay back exactly the spin cost
0.6%
pay more than the spin cost
11.9%

Each mark is one spin in a hundred, rounded to whole spins. The machine lights up for every one that pays, the losses included.

There is no decision in a slot to get better at.

This page is for entertainment, and for seeing clearly what this kind of machine does: how little 1,024 ways has to do with how often it pays, how much of the return waits inside a feature that is rare, and why a random jackpot is not something a session can work toward.

Where the return comes from, per 100 chips bet
  • The paid spins59.35%

    All 1,024 ways are in play on every one, and 76.3% of spins pay nothing.

  • The free spins33.30%

    They start on about 1 spin in 60.

  • The jackpot wheel3.26%

    It starts on 1 spin in 1,000, at random, whatever came before.

Together they return 95.92%. The machine keeps the other 4.08%.

02 / 03

Rules at this table

What one way pays, in coins. A spin costs 40
SymbolFive reelsThree reels
Bison25040
Pronghorn18030
Coyote12022
Meadowlark10018
Ace7512
King7512
Queen606
Jack606
Ten405
Nine405

One way of Nine across three reels pays back 5 of the 40 coins the spin cost: a payout smaller than the bet, which is a loss. A win is the pay times the ways it was made.

  • Five reels, four rows and 1,024 ways. Every spin plays all of them for 40 coins, at a bet of 40, 80, 200 or 400 chips.
  • A symbol pays for sitting on 3, 4 or 5 reels in a row counted from the first reel, anywhere on those reels. The win is the pay for that symbol and that run, times the number of ways it was made: how many of the symbol each reel of the run shows, multiplied together. Each symbol is paid once, for its longest run.
  • There are 10 paying symbols. Bison is the highest: one way across five reels pays 250 coins. Nine is the lowest: one way across three reels pays 5 coins, which at a bet of 40 is 5 chips back on a 40 chip spin.
  • The Thunderhead is wild. It appears on reels 2, 3 and 4 only, stands in for every paying symbol, does not stand in for the Windmill, and pays nothing of its own. There are no win multipliers.
  • The Windmill is the scatter and pays nothing. 3, 4 or 5 Windmills anywhere in view start 8, 20 or 50 free spins.
  • In the free spins, every Thunderhead that lands is given a number from 1 to 5, each equally likely, and holds its place for that many respins while every other position spins again. A respin is extra: it does not use up a free spin. The number drops by one with each respin, and the wild lets go when it runs out.
  • A Thunderhead that lands during a respin holds too, with its own number. Respins go on for as long as any held wild has one left, and every screen is paid.
  • Windmills during the free spins and their respins award more free spins on the same table, up to 200 free spins in one feature.
  • The jackpot is not on the reels. Every paid spin has a 1 in 1,000 chance of starting the jackpot wheel, whatever the reels show, and the chance is the same at every bet. The wheel pays one of five fixed prizes: Breeze at 8 times the bet, Squall at 20 times the bet, Tempest at 50 times the bet, Supercell at 250 times the bet and Stampede at 2,000 times the bet. Each prize's share of the wheel is drawn at its true size.
  • The reels pay at most 10,000 times the bet in one round, the paid spin and its free spins together, and a feature that reaches that ends there. A jackpot prize is paid on top.
  • The whole round is decided when Spin is pressed: the spin, every free spin and respin, and the jackpot draw. The animation plays it back and cannot change it.
  • Autoplay plays 10, 25, 50 or 100 spins at the current bet. It needs a loss limit before it starts, and it stops at that limit, when a bonus feature begins, when the spins run out, or when you stop it. Ordinary wins and the wild on a paid spin play through. The free spins and the jackpot wheel both stop it: a round with free spins is its last, and the wheel is handed back to you before it turns.
  • Turbo shortens the animation. It does not change the odds, the return or any result, and it does not hurry the jackpot wheel while it waits for your press.

  • Sound starts on, and the Sound button switches it off.

    Enter
    Spin, or turn the jackpot wheel when it is waiting

FAQ

Is this slot played for real money?
No. The table uses play chips that have no value, cannot be bought, and cannot be cashed out or exchanged for anything. If you run out, you are handed another stack for free. There is no account and nothing to download.
What is the RTP of Prairie Thunder?
95.92%, so the machine keeps 4.08%. It is made of three parts: 59.35% from the paid spin, counted exactly from the reel strips; 33.30% from the free spins, simulated over 200,000,000 rounds; and 3.26% from the jackpot wheel, which is arithmetic. At the smallest bet of 40 chips that works out at about 163 chips per 100 spins on average, with wide swings around it in any one session.
Does 1,024 ways mean it pays often?
No. The ways are the paths a matching symbol can take across the reels, and every one of them depends on the same five reel stops. 76.3% of spins pay nothing. 11.2% of spins pay something smaller than the bet, which is a net loss that looks like a win. Only 11.9% of spins, about 1 in 8, pay more than they cost. The free spins start on about 1 spin in 60.
Is Prairie Thunder a free alternative to Bison Fury?
Yes. It is built like Bison Fury: five reels, four rows, 1,024 ways from the first reel, a wild on reels 2, 3 and 4 with no pay of its own, a scatter that awards 8, 20 or 50 free spins, wilds that hold for 1 to 5 respins during those free spins, and a jackpot wheel that starts at random with no symbols involved. It is free, it needs no account, and it is played with chips that have no value. It is not Bison Fury itself, which is Entain's game, and it is not made, licensed or endorsed by Entain.
How is it different from Bison Fury?
The mechanic is the same family and everything else is our own: the name, the art, the sound, the reel strips and the pay table. So the numbers are different too. Prairie Thunder returns 95.92% with a 23.7% hit rate, and those are this machine's figures only. They say nothing about Bison Fury's. The jackpot differs in kind: Bison Fury's is a pooled progressive whose chance rises with the bet, and ours is five fixed prizes with the same chance at every bet, because play chips have no pool. The other difference is what sits beside the reels: the published figures, a status line that calls a payout smaller than the bet a loss, and a session coach.
Do autoplay and turbo change the odds?
No. Every spin is drawn the same way and the return stays 95.92%. The jackpot's chance stays 1 in 1,000 on each spin, however the spin was started. What they change is speed: more spins fit into an hour, and the cost of an hour is the number of spins times the 4.08% the machine keeps on each. That is why autoplay here will not start without a loss limit.
What are the odds of the jackpot, and can I improve them?
The wheel starts on 1 paid spin in 1,000. On any one spin the odds of each prize are: Breeze 1 in 1,818, Squall 1 in 3,333, Tempest 1 in 8,333, Supercell 1 in 40,000 and Stampede 1 in 200,000. Nothing improves them. The draw looks at nothing, so no spin is closer to the jackpot than any other, a long run without it does not make it due, and a bigger bet does not make it likelier here. A bigger bet makes the prize bigger and the spin cost more by the same proportion. The jackpot is 3.26% of the 95.92% return, and most sessions never see the wheel.
Can I tell when a win or the free spins are coming?
No. Each reel stops on its own, every stop on a strip is equally likely, and a spin starts from nothing. A run of blank spins does not make a win due. Two Windmills in view with no third is not a sign of anything: it pays exactly what any other losing spin pays, and the next spin has the same chance of the free spins as every other.
What is the most a spin can pay?
The reels are capped at 10,000 times the bet in one round, and the Stampede jackpot adds 2,000 times the bet, so the ceiling is 12,000 times. That is a limit, not an expectation: the largest round in 200,000,000 simulated rounds of the reels paid 4,800 times the bet. A round that pays 100 times the bet or more comes up about once in 1,787 spins.

How this game works

Each reel is a fixed strip of symbols, 83, 84, 82, 81, 78 symbols long from reel 1 to reel 5, printed in the code this page runs. A spin picks one stop on each strip with your browser's random number generator, every stop equally likely, and the 4 symbols from that stop down are what shows. The free spins use the same strips. A held wild's number of respins is one more draw, 1 to 5 with equal chance, and the jackpot is two: one for whether the wheel starts and one for where it stops.

The 95.92% return has three parts, and they are arrived at three ways. The paid spin returns 59.35%, and that is counted, not sampled: a ways win is a product of how many of a symbol each reel shows, the reels stop independently, and so its average is worked out exactly from the strips. The same goes for the chance of three or more Windmills, 1 spin in 60, and the 22.3% of paid spins that show a win themselves. The house edge on the common casino bets puts the 4.08% this machine keeps in context.

The free spins return 33.30%, and that figure is simulated, because held wilds make the feature impractical to count: what a respin pays depends on where every earlier wild landed and how long each one holds. The engine that runs the machine on this page was played for 200,000,000 rounds (8 runs of 25,000,000, with fixed seeds starting at 20261003) and the totals were recorded. An automated test replays the opening of that run from its seed and requires the identical totals, and checks that the simulated return of the paid spin agrees with the counted one. An average feature runs 11.3 free spins and 6.2 respins and pays 20.0 times the bet, and 14.6% of features pay less than the bet.

The jackpot returns 3.26%, and that is arithmetic: a 1 in 1,000 chance of the wheel, times the wheel's average prize of 32.65 bets. The shares of the wheel are Breeze 55.0%, Squall 30.0%, Tempest 12.0%, Supercell 2.5% and Stampede 0.5%, which makes the odds on any one spin Breeze 1 in 1,818, Squall 1 in 3,333, Tempest 1 in 8,333, Supercell 1 in 40,000 and Stampede 1 in 200,000.

Put together, 62% of what the machine pays back comes from the paid spin, 35% from the free spins and 3% from the jackpot. The whole-round rates come from the same simulated run with the jackpot's exact odds added: 23.7% of spins pay anything, 11.2% pay something smaller than the bet, and 11.9% pay more than the bet. The standard deviation of one spin's result is 7.95 bets, which is the size of the swings around the average.

The expected figure in the session panel is the share the machine keeps multiplied by the chips you have bet on finished spins. The coach's count of spins in the last minute is taken from when you pressed Spin.

Limits

  • The reel strips, the pay table, the jackpot prizes and the jackpot odds were designed for this page. They are not a copy of Bison Fury or of any other real machine, and these figures describe this machine only.
  • Bison Fury is Entain's game and its name belongs to its owner. Prairie Thunder is an independent alternative built on the same kind of mechanic. It is not made, licensed or endorsed by Entain.
  • The jackpot here is fixed prizes, not a progressive. A real progressive's prize grows with every bet placed on it, and its chance can depend on the size of the bet. Neither is true of this wheel.
  • The free spins' return and the whole-round rates are simulated, not counted. A run of 200,000,000 rounds has a standard error of about 0.05 points on the return, so the last digit shown could move with a different seed.
  • A real slot is usually shipped in several return settings and the casino chooses one. The same title can keep noticeably more than the figure quoted for it, and a real machine does not print its reel strips.
  • The reels are stopped by an ordinary browser random number generator. It is not an audited or certified generator, and nothing here should be read as a test of one.
  • Autoplay and turbo are here because Bison Fury has autoplay and a quick spin mode. Both make a machine cost more per hour, so autoplay will not start without a loss limit, it ends when a bonus feature begins, and the coach prices the pace while it runs.
  • Play chips do not feel like money. A long blank run is harder to sit through, and to stop after, with a real stake.

This is a practice game for adults. It has no real-money play and links to none. Bison Fury, or any slot played with money, keeps its share of every spin, and no way of timing or sizing the spins changes that. On this machine 47% of the spins that pay anything still cost more than they return, and the jackpot is one random draw in 1,000 that no spin is ever closer to.

Gambling can cause serious harm. The National Problem Gambling Helpline is free, confidential and open 24/7, call or text 1-800-MY-RESET (1-800-697-3738), or chat at ncpgambling.org/chat.

03 / 03

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