Every Megaways slot that isn’t made by Big Time Gaming exists because of a deal Diamond Mine made possible in 2018 — it was the very first game BTG licensed its own engine to, before Blueprint’s desert-canyon miners had even proven the mechanic could travel. Eight years and five sequels later, if you’re hunting for slots like Diamond Mine you’ll find the family is still Blueprint’s flagship — a cascading, gold-hunting dynasty with the industry’s best claim to “the game that started it all.” This guide reviews every generation.
Where to Play Diamond Mine Slots
Every Diamond Mine version at a glance
Six generations of the same mine, all Blueprint Gaming. Figures checked 5 July 2026:
| Game | Year | RTP | Standout |
|---|---|---|---|
| Diamond Mine Megaways | 2018 | 96.43% | The industry’s first third-party Megaways licence |
| Diamond Mine Extra Gold | 2019 | 96.43% | Adds the Gold Spins gamble wheel |
| Diamond Mine All Action | 2020 | 96.7% | Bonus-buy-only structure, no base game |
| Diamond Mine Megaways Jackpot King | 2020–21 | 94.5% | The Deluxe pot attached, up to 50,000x |
| Diamond Mine Extra Gold Megaways All Action | — | 97.03% | The family’s best published RTP |
| Diamond Mine 2 Megaways | 2023 | 95% | The redesigned sequel, high volatility |
The dynasty’s honest headline: RTPs swing nearly two and a half points across six titles, and the bonus-buy-only editions aren’t available to UK players under current feature-buy restrictions.
Every Diamond Mine game, reviewed
1. Diamond Mine Megaways (the original)
Blueprint’s May 2018 debut is quietly one of the most important slots ever released: it was the first game Big Time Gaming licensed its own Megaways engine to, before any other studio had built one. Underneath that history is a solid Wild West gold rush — 6 reels, up to 117,649 ways, cascading wins, and a TNT mystery symbol that doesn’t just substitute but actively transforms into whichever symbol completes your win. Free spins stack an unlimited multiplier on top. Published at 96.43% with a 10,000x ceiling, it still holds up nearly a decade later.
2. Diamond Mine Extra Gold
2019’s first sequel keeps the 96.43% RTP and adds a Gold Spins gamble wheel: land the bonus and you can spin to double your extra-spins total, or risk losing the feature entirely on a red segment. Same cascading engine, same TNT wild — just with a higher-stakes decision bolted onto the trigger.
3. Diamond Mine All Action
May 2020’s third entry strips out the base game entirely — you buy straight into the bonus round, at 96.7% RTP and medium-high volatility. The gamble wheel returns with sharper stakes, and scatter retriggers add five or ten extra spins depending on how many land. It’s built for players who want the free-spins feeling on demand, though UK operators can’t offer this bonus-buy structure under current feature-buy restrictions — it’s one for other regulated markets only.
4. Diamond Mine Megaways Jackpot King
Blueprint wired its flagship into the Jackpot King progressive network in 2020–21, and the toll is the family’s steepest: 94.5% published against the standalone’s 96.43%. The trade is a shot at the Deluxe pot on top of a 50,000x maximum — five times the original’s ceiling, if you never hit the jackpot at all.
5. Diamond Mine Extra Gold Megaways (All Action)
The Extra Gold engine rebuilt on the bonus-buy-only All Action structure, publishing the family’s best RTP at 97.03%. Its Golden Bet feature guarantees three-plus scatters for 50x your stake — a paid shortcut straight to the free spins, again outside UK availability under feature-buy rules.
6. Diamond Mine 2 Megaways
July 2023’s numbered sequel is the first real redesign in five years: a returning miner character, refreshed symbols, and the same Gold Bet mechanic priced into a standard base game rather than a buy-only one. Published at 95% with high volatility — a touch below the 2018 original, but the closest thing to a proper reboot this family has had.
Close cousins outside the family
Big Time Gaming’s own Bonanza is the ancestor that made this whole family possible in the first place — comparing the two is a direct lesson in how the licensor and the licensee handled the same mechanic differently. Within Blueprint’s own catalogue, Genie Jackpots and Slots O’ Gold share the studio’s house style for cascading, jackpot-linked reskins.
The complete family tree
| Game | In one line |
|---|---|
| Diamond Mine Megaways (May 2018) | The industry’s first third-party Megaways licence |
| Diamond Mine Extra Gold (2019) | Adds the Gold Spins gamble wheel |
| Diamond Mine All Action (May 2020) | Bonus-buy-only, no base game, 96.7% |
| Diamond Mine Megaways Jackpot King (2020–21) | The Deluxe pot edition, 94.5%, 50,000x ceiling |
| Diamond Mine Extra Gold Megaways All Action | The family’s best RTP at 97.03%, Golden Bet guarantee |
| Diamond Mine 2 Megaways (Jul 2023) | The redesigned sequel, 95%, high volatility |
Checked 5 July 2026. Blueprint has re-released this engine roughly every two years since 2018 — the pattern suggests a Diamond Mine 3 is only a matter of time.
The original: quick facts
| Provider | Blueprint Gaming, under licence from Big Time Gaming |
|---|---|
| First released | May 2018 |
| Layout | 6 reels, up to 117,649 ways |
| RTP | 96.43% published |
| Volatility | Medium |
| Max win | 10,000x |
| Signature feature | TNT mystery symbol that transforms into whichever symbol completes a win |
✓ Facts checked 5 July 2026
The maths: a two-and-a-half-point spread
Here’s what a hundred £1 spins costs on average, game by game:
| Game | House edge | £1 × 100 spins |
|---|---|---|
| Extra Gold Megaways All Action (97.03%) | 2.97% | £2.97 |
| Diamond Mine All Action (96.7%) | 3.30% | £3.30 |
| Original / Extra Gold (96.43%) | 3.57% | £3.57 |
| Diamond Mine 2 Megaways (95%) | 5.00% | £5.00 |
| Megaways Jackpot King (94.5%) | 5.50% | £5.50 |
✓ Calculated from the published RTPs — checked 5 July 2026
The pattern here runs opposite to most families on this site — the newest mainstream sequel (Diamond Mine 2) actually costs more per spin than the eight-year-old original, and only the buy-only All Action editions beat the 2018 game’s maths. Worth a paytable check before assuming “newer means better.” Session tools on our Responsible Gambling page.
History and legacy
Big Time Gaming invented Megaways with Bonanza in 2016 and kept the mechanic to itself for two years — until Blueprint Gaming struck the first-ever third-party licensing deal, announced by BTG’s own CEO as “ground-breaking.” Diamond Mine Megaways, released in May 2018, was the result: proof that Megaways could travel beyond its inventor and become an industry-wide standard rather than one studio’s house mechanic. Every Megaways game made by anyone other than Big Time Gaming — Reel King Megaways, Genie Jackpots Megaways, hundreds more — exists because this deal worked. Blueprint kept building on the foundation: Extra Gold in 2019, the buy-only All Action structure in 2020, a Jackpot King edition soon after, and a full redesign in Diamond Mine 2 Megaways in 2023.
Why this family still matters
Few slot franchises get to claim they changed the industry’s business model rather than just its own catalogue. This one can. Diamond Mine is the proof-of-concept that turned Megaways from Big Time Gaming’s proprietary trick into the shared mechanic that now powers thousands of games across dozens of studios — including several other families reviewed on this very site.
Beyond the reels
The Megaways licensing model Diamond Mine helped establish became one of the most consequential business decisions in modern slots — Big Time Gaming now licenses the mechanic to most major studios, turning a single 2016 invention into an entire sub-genre. Blueprint itself, a subsidiary of Germany’s Gauselmann Group, treats Diamond Mine as a flagship brand, regularly returning to the well for new editions rather than letting the franchise lapse.
What players say
The 2018 original still draws real affection from players who value its TNT mystery symbol over flashier modern mechanics, and its 96.43% RTP is frequently cited as one of the fairer bets in Blueprint’s whole catalogue. The All Action editions split opinion sharply — buy-only structures always do — while Diamond Mine 2’s redesign earns praise for visuals but occasional grumbling that the RTP dipped for a sequel that otherwise plays it safe.
The biggest Diamond Mine wins
The Megaways Jackpot King edition’s 50,000x ceiling is the family’s outright record, five times the standalone original’s 10,000x cap. But the sessions players actually rewatch are cascading free-spins runs where the multiplier climbs uncapped. Here’s a recorded session with a 25x multiplier mid-flow:
Recorded session for flavour — the mine gives up its gold on its own schedule.
Picking the best Diamond Mine slot for your session
| If you want… | Play | Why |
|---|---|---|
| The historically important original | Diamond Mine Megaways | 96.43% and the deal that started the genre |
| The best published maths | Extra Gold Megaways All Action | 97.03%, if buy-only features are available to you |
| A modern redesign | Diamond Mine 2 Megaways | Fresh visuals, the Gold Bet built into the base game |
| A progressive chase | Megaways Jackpot King | 50,000x ceiling for a lower 94.5% RTP |
Slots like Diamond Mine from other studios
Buffalo Blitz offers marathon free games, Big Bass Bonanza collects fish values, and Money Train concentrates action in the Money Cart. Diamond Mine is the medium-volatility Megaways contrast, where TNT mystery symbols transform reel outcomes.
| Series | Choose them if… | Choose Diamond Mine if… |
|---|---|---|
| Buffalo Blitz (Playtech) | You'd rather have high volatility, closer to Diamond scatters award 8–100 free games with x2/x3 wilds | You want medium volatility and Blueprint Gaming's TNT mystery symbol |
| Big Bass Bonanza (Reel Kingdom, published by Pragmatic Play) | Reel Kingdom's Fisherman wilds collect all fish values sounds more like your kind of session | You're after Blueprint Gaming's take instead — TNT mystery symbol |
| Money Train (Relax Gaming) | Relax Gaming's The Money Cart sounds more like your kind of session | You'd rather have medium volatility, built around TNT mystery symbol |
Choose the rival for free-spin volume or collection; choose Diamond Mine for variable ways combined with the TNT mystery reveal.
Our verdict on Diamond Mine Megaways
Sister Slots score: 8/10 — we’re scoring the 2018 original, the version with the strongest claim to greatness.
| Features | 8/10 — the transforming TNT wild still feels distinctive eight years on |
|---|---|
| Win potential | 7/10 — 10,000x is solid, if not the family’s biggest |
| Design | 7/10 — the canyon aesthetic has aged well |
| Playability | 9/10 — 96.43% published, and it wrote the rulebook everyone else followed |
Dig here if you want the game that made Megaways an industry standard, played at maths that still hold up. Look to the sequels if you specifically want a bigger jackpot ceiling or a fresher redesign — just check which build’s RTP you’re actually getting.
Diamond Mine FAQs
Who makes Diamond Mine?
Blueprint Gaming, under licence from Big Time Gaming for the Megaways mechanic — the very first such licence BTG ever granted.
Why is Diamond Mine historically important?
It was the first Megaways game released by any studio other than Big Time Gaming itself, proving in 2018 that the mechanic could be licensed industry-wide rather than staying one company’s proprietary trick.
How many Diamond Mine games are there?
Six main entries: the 2018 original, Extra Gold (2019), All Action (2020), Megaways Jackpot King (2020–21), Extra Gold Megaways All Action, and Diamond Mine 2 Megaways (2023).
What is the RTP of Diamond Mine?
The 2018 original and Extra Gold both publish 96.43%; the All Action editions run 96.7% and 97.03%; the Jackpot King edition drops to 94.5%; Diamond Mine 2 sits at 95%.
Which Diamond Mine has the biggest max win?
Megaways Jackpot King, at 50,000x via its progressive pot — five times the standalone original’s 10,000x ceiling.
Can UK players access the All Action bonus-buy editions?
No — UK Gambling Commission rules prohibit direct feature-buy options, so the buy-only structure of All Action titles isn’t available on UK-facing sites.
What is the TNT mystery symbol?
The original’s signature wild — rather than simply substituting for other symbols, it explodes and transforms into whichever symbol you need to complete a winning combination.
Are Diamond Mine slots fair?
Yes — Blueprint Gaming is UK Gambling Commission licensed with independently tested RNGs, and each edition’s RTP is disclosed in its paytable.
Sources & Verification
Primary sources checked 9 July 2026: Blueprint Gaming’s own corporate site; and the UK Gambling Commission’s public register (Blueprint Gaming Limited, account 6516).
Paul edits Sister Slots’ UK slot-family guides. He researches provider histories, mechanics and published game data, checking material claims against provider sources and relevant public records. Unless a page states a dated hands-on method, it reflects documented editorial research rather than real-money play. More about Paul →