3 Jewelling Diamonds Slot Review
A jewel-encrusted cabinet floats in a blue nebula, three cut-glass gems hanging above it on red, green and blue nameplates, waiting to be fed. 3 Jewelling Diamonds is that rare collector that treats patience as currency rather than an inconvenience: the progress you build towards its bonus survives stake changes, and a full gem buys certainty instead of hope. Iron Dog Studio has committed fully to the slow build, and it gives the base game a reason to exist.
It runs on a 5×4 grid with 20 winlines, pays out at 95.07% RTP and takes stakes from 0.20 to 25 per spin. The Grand Jackpot sits at 5,000x, and there’s a route to doubling it. Fans of 1 Million Fortunes Megaways and Dwarven Gems Megaways will know the studio’s fondness for collection mechanics, but this one is more patient than either. The diamonds do the work here, one coin at a time.
Base Game & Features
Wins need matching symbols on consecutive reels from reel 1 along an active winline, and wins on multiple lines add together against the total bet. Every payout follows the paytable. That’s the whole base mechanic, and it stays out of the way.
The interesting part of the game happens above the reels, where the three cut-glass gems sit waiting to be fed. Before that, one housekeeping symbol deserves a mention. Wilds appear on all five reels and substitute for all non-special symbols.
If a run of wilds is broken up by a special symbol, the win is simply calculated from the paytable. Useful, but never the point: the real business is the coins and where they go.
Jewelling Diamonds
Three coloured coin types exist, one each tied to Extra Board, Extra Spins and Extra Pays. When a coloured coin lands and doesn’t trigger Hold & Win, it’s thrown up to the matching coloured group of Jewelling Diamonds above the reels. Each hit increases that group’s fill by a random amount.
There’s a limit on supply: up to one coloured coin can appear per reel at a time, so the fill advances in single hits rather than floods. The three modifiers those coins carry are the whole toolkit of the feature. Extra Board adds a second board to the Hold & Win session, Extra Spins adds respins, and Extra Pays boosts what the round pays.
Filling a Jewelling Diamond triggers Hold & Win, and if a diamond is already full when the feature fires, that modifier is guaranteed active in the session regardless of which coins landed on the triggering spin. It’s a design that rewards staying put. The diamonds hold their value per stake level, so dropping your stake and coming back later returns them to exactly the state you left.
That progress isn’t permanent, though. At the end of a Hold & Win session, the progress of any diamond whose coloured coin effects were triggered goes back to empty. A full bonus round costs you the fill you built. The Special Multi Diamond, when it lands, activates all three coloured coin effects at once.
3 Jewelling Diamonds Bonus Features
Any of the coloured coins, or the Special Multi Diamond, can trigger the feature. Once it fires, every Hold & Win symbol locks in place: the coins, the Special Bonus symbols, the Multi Diamond and the Mini, Minor, Major and Mega Prize symbols all stick.
You start with three respins. Only positions not already occupied are active, and every new symbol that lands locks in and resets the counter back to three. The twist is the board itself: it duplicates, creating two separate Hold & Win sessions running at once.
A coin that didn’t appear on the triggering spin but lands during the feature activates its effect immediately, so a session can pick up extra modifiers as it runs. That matters when the boards are filling slowly and the respin counter is counting down.
Only Hold & Win symbols and blanks appear during the round, and blanks have no value and contribute nothing. Special Bonus symbols carry the cash values:
- 0.5x stake
- 1x, 1.5x, 2x, 2.5x, 3x stake
- 4x, 5x, 6x, 7x, 8x, 9x, 10x stake
The Jackpot Ladder
Five prize tiers climb the left rail, and they all scale with your stake:
- Mini: 15x stake
- Minor: 50x stake
- Major: 150x stake
- Mega: 1,000x stake
- Grand: 5,000x stake
Covering every position on one board with Hold & Win symbols pays the Grand tier, and there’s a step beyond it. If the Extra Board coin is in play and you fill both boards, the Grand pays out twice for 10,000x. That double Grand is the number the whole design points at, and it’s the reason the Extra Board fill matters more than the other two put together.
Bonus Buy
There’s a Bonus Buy that takes you straight into the Hold & Win, and it presents two options, of which one is priced:
- Option 1: Hold & Win with 1 random feature, 60x your stake
Sixty times the stake for one random modifier is a premium price when the same feature can arrive free off a full diamond. The buy does guarantee you skip the fill, which is the long part of the game. The random feature also means you can’t choose which modifier you get.
One safeguard applies either way. Coins collected during a round are retained if the game resets or you’re disconnected, so a session in progress is never lost to an interruption.
The bulk of any win comes from the locked symbols and prize tiers rather than the base lines, so the round is decided by how densely the boards fill. Blanks are the enemy: every respin that lands nothing burns one of your three. A full board needs 20 positions covered on a single grid.
Our Honest Verdict
Overall Rating: 7.2/10
Most of a session here is spent watching three gems fill, one coin at a time, and that’s exactly why somebody would pick it over a dozen louder games: the gems remember you, and a full one turns a bonus trigger into a sure thing. It’s a slot you settle into rather than chase.
The best thing Iron Dog has done is make that patience permanent. Progress survives stake changes, and the bonus you’ve earned arrives with its modifier locked in. The worst is what the round costs afterwards: a triggered diamond resets, so every payoff burns months of fill in a single spin, and the twin-board Grand needs everything to land right on top of that.
This suits the patient kind of player, the one who enjoys a long build with a jackpot at the end of it. Anyone after fast triggers and constant action will find the gaps between coins long. For the builders, though, the gems stay lit, and that’s a rarer pleasure than it sounds.
3 Jewelling Diamonds FAQs
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What is the RTP of 3 Jewelling Diamonds?
3 Jewelling Diamonds has an average RTP of 95.07%, which sits a little below the figure most modern slots run at. -
How many paylines does 3 Jewelling Diamonds have?
The game has 20 winlines running from left to right across the reels. Wins need matching symbols on consecutive reels from reel 1, and wins on multiple lines are added together. -
What is the grid size of 3 Jewelling Diamonds?
It’s a 5×4 grid: five reels, each four symbols high, with 20 winlines across them. -
What is the minimum and maximum bet on 3 Jewelling Diamonds?
Stakes run from 0.20 to 25.00 per spin. Changing your stake doesn’t lose your Jewelling Diamonds progress, which returns to its previous state if you switch back. -
Who makes 3 Jewelling Diamonds?
3 Jewelling Diamonds is made by Iron Dog Studio. -
How do you trigger the Hold & Win in 3 Jewelling Diamonds?
Hold & Win can be triggered by any coloured coin (Extra Board, Extra Spins or Extra Pays) or the Special Multi Diamond landing on the board. It also triggers automatically when a coloured coin hits a fully filled Jewelling Diamond, and any diamonds already full at that moment guarantee their modifiers for the session. -
What does the Special Multi Diamond do in 3 Jewelling Diamonds?
The Special Multi Diamond activates all three coloured coin effects at the same time for the whole Hold & Win session, and it can also trigger the feature on its own. -
Does the Hold & Win in 3 Jewelling Diamonds retrigger?
You get 3 respins to start, and every new Hold & Win symbol that lands locks in place and resets the counter back to three. The board also duplicates at the start of the feature, giving you two Hold & Win sessions at once. At the end of the round, any Jewelling Diamond whose coin effect was used resets to empty.
