Bison Boom

Bison Boom Slot Review

Bison Boom is a hold-and-collect game wearing a five-of-a-kind costume, and it holds back nearly everything that makes it interesting until the round you have to wait longest to reach. The base game pays left to right like a thousand other countryside slots; the real money and the real ideas both live behind three scatters. All of which makes the setting faintly ironic, because the game itself is beautiful – dusk on the Great Plains, a gold-framed reel set, lavender mountains catching the last orange light, and a wooden crate with dynamite on its lid waiting in the long grass.

Northern Lights Gaming have built it on a 5×3 grid with 20 fixed paylines, medium volatility, a 96.15% RTP and stakes from 0.20 to 20.00. The studio’s bison herd has been here before, in Bison Moon Megaways and Bison Moon Power Combo, alongside wider catalogue entries like ClusterBuck. Whether the dynamite in the grass ever goes off is the question the rest of this answers.

Base Game & Features

This is a straightforward left-to-right payer. Wins need matching symbols on adjacent reels from reel one, only the highest combination counts per payline, and the total payout is the sum of every winning line from the spin. The Bear is the symbol worth chasing; the royals are the filler they always are.

Every value below is a multiple of the line stake:

• Bear – 3 pays 2x, 4 pays 4x, 5 pays 8x
• Wolf – 3 pays 1x, 4 pays 2x, 5 pays 4x
• Eagle – 3 pays 0.6x, 4 pays 1.5x, 5 pays 3x
• Raccoon – 3 pays 0.5x, 4 pays 1x, 5 pays 2x
• A – 3 pays 0.4x, 4 pays 0.5x, 5 pays 1x
• K – 3 pays 0.3x, 4 pays 0.4x, 5 pays 0.8x
• Q – 3 pays 0.2x, 4 pays 0.3x, 5 pays 0.6x
• J – 3 pays 0.1x, 4 pays 0.2x, 5 pays 0.5x

Wilds appear in the base game only and substitute for everything except the scatters. Scatters land on reels 1, 3 and 5, carry no payout of their own, and can’t be substituted. They do two jobs, and the game splits them between two systems.

Bison Wild Boom

Mini Dynamite tokens spin in on the reels and collect into the Wild Crate that sits in the grass at the bottom left of the screen. After a spin, the crate can randomly explode and scatter up to 15 Bison Wild symbols across the reels. It’s base game only, it costs nothing extra, and it’s the one thing that breaks up the plain five-of-a-kind routine between bonuses.

Feature Upgrade

Land 2 scatters on reels 1 and 3 in the same spin and a token goes into the Feature Upgrade meter that runs overhead on a banner. Collect 10 tokens and a row unlocks in the Bison Spins feature; collect 40 and all rows unlock. Four padlocked rows sit up there waiting.

The meter resets once the tokens are used in Bison Spins, and progress is saved per bet level. The meter you build at 1.00 isn’t the meter you’ll find if you drop to 0.20. It’s a long build, and the saving grace is that it remembers where you left it.

Bison Boom Bison Spins & Bonus Features

Three scatters trigger Bison Spins, a Link&Win round played on special reels containing only Moons, blanks and feature modifier symbols. It starts with 3 respins and however many rows the Feature Upgrade meter has unlocked. Each blank position spins individually, and any Moon or modifier that lands resets the respins to 3. Moons hold in place, and the round ends when the respins run out or the reels fill.

Moon values split by colour: Red Moons carry up to 7x bet, Blue Moons anything over 7x, and modifiers can upgrade reds to blues. Seven modifier symbols can land during the round:

• Collector – combines all landed Moons into one
• Adder – carries 1x, 2x, 5x, 10x or 20x bet, adds its value to every Moon, lasts one spin
• Persistent Adder – the same, but lasts all remaining spins
• Splitter – splits random Moons into double or quad Moons
• Doubler – doubles the value of random Moons
• Key – removes one padlock from the locked rows
• Bomb – blows away every remaining padlock and adds a random number of Moons

Fill every reel position with Moons and 2,000x the current bet is added to the total, which stands as the game’s top stated prize. What a full board with upgraded Blue Moons and a Persistent Adder running might total beyond that is between you and the maths.

Upsizer

When Bison Spins triggers, the Upsizer offers guaranteed modifiers at a calculated cost. The options:

• No 1x Moons – eliminates 1x Moons landing during the feature
• Bomb – guarantees the Bomb modifier lands
• Splitter – guarantees the Splitter lands 3 times
• Persistent Adder – guarantees the Persistent Adder lands
• Upsizer Max – takes everything on offer

The maths shifts depending on how you enter. Bison Spins triggered naturally runs at 96.15%, and with Upsizer enabled that rises to 96.57%. Buying the feature keeps 96.15%, but buying it and taking Upsizer drops to 96.04%.

That last figure is the one to sit with. The add-ons priced into a purchased round are the one place the game quietly charges you twice.

Buy Feature

A BUY button sits on the left of the screen in the base game. Press it and Bison Spins triggers instantly, at the price displayed for the current bet, and the round plays at that bet. The row unlocks you’ve built carry into a purchased round, so the meter work isn’t wasted if you’d rather skip the wait.

Our Honest Verdict

Overall Rating: 7.7/10

You play Bison Boom mostly for the moment those padlocks give way. Sessions here are long stretches of modest line wins, broken up by an occasional crate of wilds, with four locked rows ticking up overhead like a promise the game fully intends to keep – eventually. That promise is the whole reason to sit down at this particular prairie.

Bison Spins earns it. Because rows can unlock mid-round through keys and bombs, no two rounds play the same shape, and the full-board 2,000x is a target the modifiers genuinely let you chase rather than just admire. It’s the rare hold-and-collect that gets better the more of it you’ve unlocked.

The price of that is patience. Rows arrive ten two-scatter spins at a time, on two named reels, and the shortcut charges you twice – the buy costs its premium, and the Upsizer shaves the return to 96.04%. This one suits players who like watching a meter fill and cashing it in themselves; it’s a poor fit for anyone who wants the finished article from spin one. Stick with it, though, and the dynamite in the grass does go off.

Bison Boom FAQs

Common questions about Bison Boom:

• What is the RTP of Bison Boom?

  96.15%. Enabling the Upsizer when Bison Spins triggers naturally raises it to 96.57%, while buying the feature keeps 96.15% and buying it with Upsizer drops it slightly to 96.04%.
• How do you trigger the Bison Spins feature?

  Land 3 scatter symbols on reels 1, 3 and 5. Scatters can’t be substituted by wilds and carry no payout of their own; 2 scatters on reels 1 and 3 instead add a token to the Feature Upgrade meter.
• What does the Feature Upgrade meter do?

  Each token collected from 2-scatter spins fills the meter. 10 tokens unlock one row in the Bison Spins feature, 40 unlock all rows. Once the tokens are spent in Bison Spins the meter starts again, and progress is saved per bet level.
• What are Red and Blue Moons in Bison Boom?

  Moons are the held cash symbols in Bison Spins. Red Moons carry a multiplier of up to 7x your bet, Blue Moons carry over 7x, and feature modifiers can upgrade Red Moons to Blue.
• Is Bison Boom high volatility?

  No, it’s a medium volatility slot, with a hit frequency of 33.55%, so wins land roughly every third spin on average.
• Can you buy the bonus on Bison Boom?

  Yes. A BUY button in the base game instantly triggers Bison Spins at the price displayed for your current bet, and the round plays at that bet. Your unlocked Feature Upgrade rows carry into a purchased round.
• How many paylines does Bison Boom have?

  20 fixed paylines on a 5×3 grid, paying left to right from reel one, with only the highest combination counting per line.
• When is Bison Boom released?

  Bison Boom’s release date is 10 July 2024. It’s made by Northern Lights Gaming.