Jammin’ Jars was the game that put Push Gaming on the map. Released in September 2018, it landed on the UK slots scene doing something most games weren’t doing: a proper 8×8 cluster pays grid, no paylines, disco fruit aesthetic, and a Wild Jar mechanic built around multipliers that compound through cascades with no cap. Seven years later it’s still regularly appearing in big win charts.
It’s not a game without caveats. The high volatility is genuinely brutal — this is a session-eater that requires a proper bankroll to sustain. The base game can feel like dead air between Rainbow Features. And there’s a variable RTP element that’s worth understanding before you commit to a specific casino.
Here’s the full picture.
Jammin’ Jars — Quick Stats
| Category | Detail |
|---|---|
| Developer | Push Gaming |
| Released | 14 September 2018 |
| RTP | 96.83% (variable — see below) |
| Volatility | High |
| Max Win | 20,000x stake (highest recorded: 19,998.5x) |
| Grid | 8×8 |
| Win mechanic | Cluster pays — 5+ matching symbols horizontally or vertically |
| Paylines | None — cluster pays only |
| Min Bet | £0.20 |
| Max Bet | £100 |
| Wild symbol | Jam Jar — sticky, with growing multiplier |
| Scatter / Free Spins trigger | Jam Jar — 3+ anywhere triggers Free Games |
| Bonus buy | Not available in UK (UKGC banned) |
| Mobile compatible | Yes — HTML5, all devices |
The Cluster Pays Mechanic — How Jammin’ Jars Actually Works
If you’ve only played traditional payline slots, Jammin’ Jars requires a mental reset. There are no paylines. No left-to-right symbol paths. Instead, wins form when five or more identical symbols are connected horizontally or vertically anywhere on the 8×8 grid.
Think of it like a tile-matching puzzle game. A cluster of 6 blueberries touching each other in an L-shape across the grid is a win. A diagonal connection is not — symbols must share an edge, not a corner. The win pays based on the number of symbols in the cluster, not a fixed payline multiplier.
After a win, the matching symbols are removed and new symbols cascade down from above to fill the gaps — the avalanche / cascading mechanic. This can create chain reactions where new clusters form from the refilled positions, and those wins then also clear, triggering further cascades. A single spin can chain multiple wins from one set of falling symbols.
For a deeper breakdown of how cascading symbols work mathematically, see our Cascading Reels Explained guide — the principles apply directly to Jammin’ Jars’ grid format.
The Paytable
There are six fruit symbols. Payouts are per cluster, scaled by cluster size. Strawberry is the highest paying; lower-value symbols contribute to clusters but build toward wins with multiple jars more than they deliver standalone payouts. The Jam Jar itself contributes to clusters as both a wild and a cluster-forming symbol — which is unusual and important for understanding how big wins build.
| Symbol | 5 in cluster | 8 in cluster | 12+ in cluster |
|---|---|---|---|
| Strawberry | 1x stake | 2x stake | 5x stake |
| Orange | 0.75x | 1.5x | 4x |
| Raspberry | 0.5x | 1x | 3x |
| Apple | 0.4x | 0.8x | 2x |
| Plum | 0.3x | 0.6x | 1.5x |
| Blueberry | 0.2x | 0.4x | 1x |
Base game cluster payouts are modest — the paytable above shows why. A 5-symbol strawberry cluster at £1 stake pays £1. You’re not building to 20,000x through base game symbol payouts. You’re building through the Wild Jar multiplier system, which is where the game’s max win potential lives entirely.
The Wild Jar — The Core Mechanic Worth Understanding
The Jam Jar symbol is simultaneously a Wild, a Scatter, and the game’s primary win-building mechanism. Here’s how it works:
As a Wild: substitutes for all fruit symbols to form or extend clusters.
As a Multiplier: each Jar has its own multiplier value, starting at 1x. Every time the Jar is involved in a winning cluster — either by substituting or by being part of a cluster itself — its multiplier increases by 1x for the next cascade. A Jar that contributes to three consecutive wins has a 4x multiplier (1x start + 3 increments). Two Jars in the same cluster combine their multipliers multiplicatively: a 4x Jar and a 3x Jar in the same win = 12x on that cluster pay.
As a Sticky Wild: after any winning cascade that involves a Jar, the Jar moves to an adjacent empty position and stays on the grid. It doesn’t disappear with the winning symbols — it persists, repositions, and its multiplier carries over.
The maths of escalation: this is what creates the 20,000x max win potential. Multiple Jars on the grid during a cascade chain, each accumulating multipliers independently, can combine to produce multiplied payouts of extraordinary scale. Two Jars each at 10x in the same cluster = 100x multiplier on that cluster pay. The base cluster payout of even modest symbols multiplied by 100x on a larger cluster produces numbers that turn a £1 bet into hundreds of pounds.
The honest caveat: reaching multiplier values of 10x+ on multiple simultaneous Jars during a cascade chain requires both triggering the feature and sustaining a long win sequence. It’s possible — you’ll see it in real-money big win clips regularly — but it’s rare enough that sessions without it are the norm, not the exception.
The Rainbow Feature
The Rainbow Feature is randomly triggered after any spin that produces no win. A rainbow animates across the grid and deposits one or more oversized “Mega” fruit symbols (3×3 blocks) onto the board. Because a 3×3 block occupies 9 positions and counts as 9 connected identical symbols, it immediately forms a winning cluster by itself — and can extend into massive clusters if the surrounding grid contains the same symbol.
Key detail: the Rainbow Feature is not available during Free Games — it only triggers in the base game. This distinction matters because it means the base game has a random win guarantee mechanic that free spins don’t have. Base game dead spins don’t chain indefinitely; eventually the Rainbow Feature fires and delivers something.
The Rainbow Feature doesn’t interact with Jar multipliers in the same way as cascading wins. If a Mega symbol from the Rainbow lands adjacent to an existing Jar, the Jar can be part of the resulting cluster win and gain a multiplier increment. But the Mega symbol itself doesn’t carry a multiplier — it’s a cluster-size bonus, not a multiplier bonus.
Free Games — Where the Max Win Lives
Trigger: 3 or more Jam Jar symbols anywhere on the 8×8 grid.
Base award: 6 Free Games.
Jar carryover: all Jars that triggered the feature remain on the grid throughout Free Games as sticky Wilds, with their current multiplier values intact.
The number of Jars entering Free Games is critical to outcome potential:
| Jars at trigger | Practical impact | Max win potential |
|---|---|---|
| 3 Jars | Standard free spins — Jars grow multipliers across 6 games | Moderate — depends on cascade chains |
| 4 Jars | Significantly higher multiplier ceiling — 4 Jars multiplying together creates much larger combined values | High — 4 multipliers combining can reach 4-figure stake wins |
During Free Games, Jars continue their behaviour from the base game: after each win they’re part of, they move to an adjacent empty position and their multiplier increments by 1x. There’s no reset between Free Games spins — a Jar that enters Free Games at 3x and contributes to four wins during the feature ends that feature at 7x. Multiple Jars compounding through 6 free spins with productive cascades is what creates the documented 19,998.5x observed maximum win.
The Rainbow Feature does not trigger during Free Games. This is a meaningful variance consideration: the base game has a safety net (Rainbow fires on non-winning spins); Free Games don’t. Free Games sessions without cascade chains produce very little — the 6 spins can expire with minimal wins if the grid doesn’t connect clusters around the Jars.
The Variable RTP — What to Check Before Playing
This is the section most Jammin’ Jars reviews don’t cover adequately. Push Gaming publishes “RTP may vary per casino” on the game’s official page. The headline RTP of 96.83% is the full version — but casinos can and do operate the game at a lower RTP setting.
This matters. A casino running Jammin’ Jars at a lower RTP setting (Push Gaming offer variants) means you’re playing a mathematically inferior version of the game with no visible indication at the slot interface. The difference between 96.83% and a reduced setting could be 1–2 percentage points, which compounds significantly over a session.
Practical approach: check whether your chosen casino publishes game-specific RTP data. Most major UKGC-licensed operators do — usually accessible through the game’s information screen or the casino’s responsible gambling section. Casumo and 10Bet are transparent about RTP settings. If a casino won’t disclose the specific RTP variant it runs, that’s a red flag worth acting on.
Bankroll Requirements — Be Honest With Yourself
Jammin’ Jars is high volatility in a category (cluster pays with multiplier mechanics) that can feel deceptively approachable due to the cheerful aesthetic. The 8×8 grid, bright colours, and disco soundtrack create a session feel closer to a casual mobile game than to, say, Dead or Alive 2. Don’t let that mislead you.
The base game between Rainbow Features and free spins triggers can run 50–100+ spins with nothing significant. At £1/spin, that’s £50–£100 potentially in dead play before the game does anything interesting. At £2/spin, those same dry spells cost £100–£200.
Minimum recommended session bankrolls:
| Stake per spin | Minimum session budget | What you’re buying |
|---|---|---|
| 20p | £15–20 | Enough spins for Rainbow Features and a reasonable free spins trigger probability |
| 50p | £40–50 | Comfortable session — sustains variance without depleting on a short dry spell |
| £1 | £80–100 | Standard session — covers typical dry spell duration at this stake |
| £2 | £160–200 | Required for meaningful high-variance sessions |
| £5 | £400+ | Serious play — equivalent to Bonanza-level bankroll commitment |
The 20p minimum stake is a genuine differentiator. For players who want to experience the mechanics without significant bankroll risk, the 20p minimum allows proper engagement with the cluster pays system, Rainbow Feature, and free spins triggers at very low absolute cost.
Jammin’ Jars vs Jammin’ Jars 2 — Which Should You Play?
Push Gaming released the sequel in 2021. Here’s the comparison:
| Jammin’ Jars (Original) | Jammin’ Jars 2 | |
|---|---|---|
| RTP | 96.83% (variable) | 96.40% (increases with Gold Vinyl level) |
| Max Win | 20,000x | 50,000x |
| Grid | 8×8 | 8×8 |
| Volatility | High | Very High |
| Core mechanic | Wild Jar + Rainbow Feature | Wild Jar + Rainbow Feature + Giga Jar + Gold Vinyl collection |
| Giga Jar feature | No | Yes — 8 free spins, 3 Wild Jars, up to 4×4 Giga Jar with random coin prize |
| Gold Vinyl mechanic | No | Collect Vinyls across sessions to level up RTP (max +0.5% at MAX level) |
The verdict: the original has a higher base RTP (96.83% vs 96.40%) and lower volatility. For players who want the Jammin’ Jars experience with better mathematical efficiency and more manageable session variance, the original wins.
Jammin’ Jars 2 is the right choice if you specifically want the 50,000x max win ceiling and don’t mind the additional complexity of the Gold Vinyl collection mechanic and the higher volatility that comes with it. The Giga Jar free spins mode adds a genuinely distinct feature layer — starting a Giga Jar round with only coin symbols on the grid and 3 Wild Jars pre-loaded is spectacular when it runs well.
Note: the RTP level-up mechanic in Jammin’ Jars 2 (Gold Vinyls → improved RTP up to 96.90% at MAX) means dedicated regular players see marginally better returns over time — though the practical improvement is small and requires sustained play to accumulate.
Jammin’ Jars Pros and Cons
| Pros | Cons |
|---|---|
| 96.83% RTP — above average for cluster pays format | Variable RTP — some casinos run lower variants; always check |
| 20,000x max win — credible and documented (19,998.5x recorded) | High volatility — base game can run 100+ spins without significant wins |
| Wild Jar multiplier mechanic is genuinely distinctive — uncapped growth | Rainbow Feature absent from Free Games — no safety net during the key feature |
| 20p minimum stake — genuinely accessible for low-budget play | Bonus buy unavailable in UK (UKGC ban) — must wait to trigger naturally |
| Cluster pays mechanic rewards understanding — game rewards grid awareness | Base game paytable is modest — Cluster pays without Jars deliver small wins |
| Excellent mobile implementation — 8×8 grid well-optimised for touchscreen | Sequel (Jammin’ Jars 2) has higher 50,000x ceiling if that matters to you |
Who Is Jammin’ Jars For?
Jammin’ Jars is the right game if: you understand high-volatility play and budget accordingly, you enjoy cluster pays mechanics (if you’ve played Sweet Bonanza or Reactoonz you’ll feel at home), and the Wild Jar compounding multiplier concept excites you rather than confuses you. The 20p minimum makes it genuinely accessible for casual play at low cost.
It’s the wrong game if: you want regular base game wins to sustain your balance, you’re working through a casino bonus with a wagering requirement (the high volatility means high variance outcomes during clearing), or you want a simple slot without grid mechanics to track. For high-volatility play with more conventional mechanics, Bonanza Megaways offers comparable win potential with a structure more players find intuitive.
SlotGamer verdict: 8.5/10. Push Gaming built something genuinely different in 2018 and it’s held up well. The Wild Jar multiplier system remains one of the more elegant big-win mechanisms in cluster pays slots — the compounding logic is learnable and the payoff when it clicks is spectacular. The variable RTP caveat and brutal variance require honest bankroll planning, but for the right player this is a near-perfect high-stakes cluster pays game.
For context on how the cluster pays mechanic compares to Megaways and traditional paylines, see our Slot Game Mechanics guide and Paylines Explained.
Frequently Asked Questions — Jammin’ Jars Slot
What is the RTP of Jammin’ Jars?
The full RTP of Jammin’ Jars is 96.83%. However, Push Gaming notes on their official game page that “RTPs may vary per casino” — meaning some UK casinos run the game at a reduced RTP setting. Always check the specific RTP your chosen casino operates before playing. Major UKGC-licensed operators typically display game-specific RTP in the game information screen or through their responsible gambling tools. The 96.83% figure is above average for online slots and above average for cluster pays games specifically.
How does the Wild Jar multiplier work?
Each Jam Jar symbol on the 8×8 grid has its own multiplier, starting at 1x. Every time a Jar is part of a winning cluster — either as a Wild substitution or as a cluster member — its multiplier increases by 1x for the next cascade. The Jar then moves to an adjacent empty position and remains on the grid. Multiple Jars’ multipliers combine multiplicatively when they’re both part of the same win: a 3x Jar and a 4x Jar in the same cluster produce a 12x multiplier on that pay. This compounding through cascades with no cap is what creates the 20,000x maximum win potential.
How do you trigger free spins in Jammin’ Jars?
Land 3 or more Jam Jar scatter symbols anywhere on the 8×8 grid to trigger the Free Games feature. You receive 6 free spins, and all Jars that triggered the bonus carry over to the free games as sticky Wilds with their current multiplier values. The more Jars that trigger the feature (max 4), the greater the potential multiplier combinations across the 6 free spins. Note: the Rainbow Feature does not trigger during Free Games — there’s no guaranteed win mechanic during the free spins round.
What is the maximum win on Jammin’ Jars?
The theoretical maximum win is 20,000x stake. The highest recorded real-money win is 19,998.5x stake. Reaching this requires multiple Wild Jar multipliers compounding through sustained cascade chains during Free Games — typically 4 Jars entering Free Games with high multiplier values from base game activity, then continuing to accumulate through productive cascade sequences during the feature.
Is Jammin’ Jars high volatility?
Yes — Jammin’ Jars is high volatility. This means wins are infrequent but potentially large when they arrive. The base game between significant wins can run 50–100+ spins without major pays. The Rainbow Feature (randomly triggered on non-winning base game spins) provides some base game variance relief by guaranteeing occasional cluster wins, but Free Games can also produce low returns if cascades don’t form around the Jars. Budget at least 80–100× your stake for a session to sustain the variance properly.
Is Jammin’ Jars or Jammin’ Jars 2 better?
Depends what you want. The original has a higher base RTP (96.83% vs 96.40%) and lower volatility, making it the better mathematical and variance choice for most players. Jammin’ Jars 2 adds a 50,000x max win (vs 20,000x), the Giga Jar feature (8 free spins with pre-loaded Wild Jars and coin-only grid), and a Gold Vinyl level-up system that incrementally improves RTP to a max of 96.90% for dedicated regular players. For casual play, the original wins on pure maths. For players specifically chasing the highest win ceiling or interested in the Giga Jar mechanic, Jammin’ Jars 2 is worth the lower base RTP trade-off.
Can I use bonus buy on Jammin’ Jars in the UK?
No. The UK Gambling Commission banned bonus buy (feature purchase) features for UK-licensed casinos in October 2021. The 84× stake bonus buy that unlocks 6 Free Games directly is not available to UK players — you must trigger Free Games through natural gameplay by landing 3+ Jam Jar symbols on the grid.
What makes the Rainbow Feature different from the free spins?
The Rainbow Feature triggers randomly in the base game only after a non-winning spin. It adds one or more oversized 3×3 Mega fruit symbols to the grid, which immediately form winning clusters. The feature acts as a base game variance buffer — non-winning dead spins can’t chain indefinitely because the Rainbow will eventually fire. The Free Games feature is different: 6 free spins triggered by 3+ Jam Jars, with those Jars staying on the grid as sticky Wilds with growing multipliers throughout. The Rainbow Feature does not trigger during Free Games. The two features are entirely separate mechanics with different trigger conditions and different game states.
Where can I play Jammin’ Jars in the UK?
Jammin’ Jars is widely available at UKGC-licensed UK casinos. Push Gaming titles are stocked by Casumo, Ladbrokes, Coral, 10Bet, Gala and most major operators. When choosing where to play, check whether the casino publishes the specific RTP variant it runs for Jammin’ Jars — you want the full 96.83% version, not a reduced setting. Casumo in particular is known for transparent RTP disclosure and regularly features Push Gaming titles in their promotions.