Play Demo
Every spin lands blank. That is not a flaw, that is the whole point! 3 Coin Volcanoes by 3 Oaks Gaming (also distributed under the Booongo label) strips out regular play payouts entirely, banking everything on a Hold & Win bonus that can arrive packing up to three distinct volcanic features at once. Play the free demo and you will understand the logic within a few spins.
The grid runs four reels by three rows, with one to three horizontal paylines available. Each active line costs a separate stake, so selecting all three triples your total bet while tripling the chance of triggering the Bonus Game. That trade-off sits at the centre of every session: commit to one line cheaply, or maximise your trigger odds by spreading across all three.
No symbol on the reels pays anything in regular play. The reel set contains the special symbols described below, and they exist only to set up the Bonus Game or to stick around until it arrives.
Sticky Coins appear at random during regular play and hold their position on the reels until the Bonus Game launches. Each one carries a cash value between 5x and 9x your base bet. There is one important catch: changing your bet stake while Sticky Coins are on the reels removes them entirely. They are tied to the bet level that generated them and will not carry over if you adjust your wager.
Fire Marks are overlay symbols in three colours. Green marks feed the Life Volcano counter above the grid, red marks feed Multi Volcano, and blue marks feed Grow Volcano. Collecting enough Fire Marks of a given colour activates that volcano’s feature for the Bonus Game alongside the standard trigger.
Both Mystery types sit on the reels and reveal their identity at the end of the Bonus Game, one by one. The standard Mystery symbol can transform into any other bonus symbol except Sticky Coin. The Mystery Jackpot variant is more restricted: it converts exclusively into Mini, Minor, or Major jackpot coins. Neither type reveals during the bonus itself, so their value accumulates as a surprise at the close.
When a Coin Collect symbol lands during the Bonus Game, it immediately sweeps the value of every coin and jackpot currently visible on the reels into a single collected total. Any multipliers active at that moment are applied to those prizes before collection takes place. After collecting, the Coin Collect symbol sticks to its position and remains there until the bonus ends.
The Bonus Game triggers when four symbols cover at least one active payline. It runs as a Hold & Win format: three respins at the start, with the counter resetting to three every time a new symbol lands. The bonus ends when the respin counter runs out or all positions fill.
Which volcano features are active during the bonus depends on which Fire Mark types were collected beforehand, or on which Buy Bonus option was selected.
Active when green Fire Marks were collected. Life Volcano grants one guaranteed respin counter refill during the bonus. In practical terms this functions as an insurance spin: when the counter would otherwise reach zero and end the session, Life steps in and resets it to three.
Active when red Fire Marks were collected. Multi Volcano triggers the Eruption feature at least once during the bonus, and the feature can fire multiple times. Each Eruption places between one and eight multipliers on random grid positions. If two or more multipliers land on the same cell, the values combine rather than stack separately: the cell’s multiplier increases by one for each additional hit. All multipliers are applied to the final total at the end of the Bonus Game, not as they land.
Active when blue Fire Marks were collected. Grow Volcano expands the grid by adding two rows, converting the layout from 4×3 to 4×5. This unlocks the Royal Jackpot, which requires filling all twenty positions on the expanded grid. If Grow Volcano is not active and all twelve standard positions fill, the Grand Jackpot pays instead.
All five jackpots pay at fixed multipliers of the base bet per line. The full ladder confirmed in the in-game rules panel is below.
| Jackpot | Value | Condition |
|---|---|---|
| Royal | 2,000x | Fill all 20 positions (Grow Volcano active) |
| Grand | 500x | Fill all 12 positions (standard grid) |
| Major | 50x | Random appearance during bonus |
| Minor | 20x | Random appearance during bonus |
| Mini | 10x | Random appearance during bonus |
Standard coin prizes range from 0.2x to 4x base bet. The complete set of possible bonus symbol values confirmed by the in-game panel is 0.2x, 0.4x, 0.6x, 1x, 1.2x, 1.4x, 2x, 3x, 4x, 5x, 6x, 7x, 8x, and 9x , with values at the higher end exclusive to Sticky Coins.
Bet range runs from £0.10 to £55 per active line, giving a total stake range of £0.10 to £165 depending on the number of lines selected. Three Buy Bonus options are available where the feature is permitted.
| Option | Cost | What you get |
|---|---|---|
| Random Bonus | 40x base bet | Bonus Game with 1, 2, or 3 features randomly assigned |
| Bonus Trio | 75x base bet | Bonus Game with all three volcano features active |
| Multi Madness | 300x base bet | All three features plus Eruption are guaranteed on every single respin |
One detail worth noting: any Sticky Coins on the reels at the time of a Buy Bonus purchase do not carry into the purchased Bonus Game. The bought session runs independently, and the existing sticky symbols are excluded.
