Cluster pays slots explained

What are cluster pays slots?

In a cluster pays slot there are no reels in the usual sense and no paylines. Instead, the game fills a grid with symbols, often 7 × 7 or 8 × 8, and looks for groups of the same symbol that touch. Any group that reaches the minimum size, typically five, pays. You do not need the symbols in a straight line or starting from the left; they just need to connect.

NetEnt's Aloha! Cluster Pays (2016) is one of the best-known early examples, and the format has since spread across many studios. Play'n GO built a run of grid games around it, including Reactoonz and Gemix, Push Gaming made Jammin' Jars one of its best-known titles, and Pragmatic Play applied it to Sugar Rush and Fruit Party. Our online slots guide shows where cluster games sit among other formats.

How cluster pays slots count a winning cluster

Every cluster game uses the same basic test: start from one symbol, step to any identical neighbour above, below, left or right, and keep going until there are no more matches. The total number of connected symbols is the cluster size.

In the grid above, the A symbols at row 1 col 2, row 1 col 3, row 2 col 3, row 3 col 3, row 3 col 4 and row 4 col 4 all join edge to edge, so they form a cluster of six. The A at row 5 col 1 is on its own and does not count. The two Cs at row 1 col 4 and row 2 col 4 make a pair, too small to pay. If the game counted diagonals, more symbols might link, which is why the help screen always states the connection rule.

• Wilds in cluster games usually join any adjacent cluster and can link two groups into one.
• Hexagonal grids, such as Play'n GO's Honey Rush (37 cells), give each cell six neighbours rather than four, so clusters form differently.
• Several clusters can pay on the same spin, and the same symbol can form two separate clusters if they do not touch.

Cluster size and payouts: why bigger groups pay much more

Cluster paytables list a prize for each size band of each symbol. Prizes rise slowly at first, then sharply, because large clusters are rare. The table below is an illustration of the typical shape, not the paytable of any real game.

Note that in this illustration the smallest cluster returns less than the stake, which is common. A 50p spin that pays 25p is a 25p loss, and under UK rules the game must not celebrate it as a win. Minimum sizes also vary: Play'n GO's Tome of Madness pays from four symbols, while NetEnt's Aloha! Cluster Pays needs nine.

Popular cluster pays slots and their published figures

Figures come from developers' published game information; the casino you use may run a lower RTP version, so check the help screen. Studios that build heavily on grids include Play'n GO, Push Gaming and Hacksaw Gaming. Big Time Gaming's Megaclusters, used in Star Clusters Megaclusters, is a variation in which symbols split into smaller ones and the grid grows; see the Big Time Gaming page.

Cluster pays and cascades: how one spin becomes a chain

Almost every cluster game pairs the mechanic with cascading reels, sometimes called tumbles or avalanches. After a winning cluster pays, its symbols disappear, everything above drops down and new symbols fill the gaps. If a new cluster forms, it pays and the process repeats. The chain ends when a fill produces no win.

A worked example at a 50p stake: the first fill forms a cluster of 7 paying 1x (50p). The cascade creates a cluster of 5 paying 0.5x (25p). The next cascade forms a cluster of 11 paying 5x (£2.50). The fourth fill produces nothing, so the spin ends with £3.25 returned from one 50p stake. These numbers are illustrative; the point is that a single stake can produce several separate wins.

Many cluster games add something that grows through a chain. In Pragmatic Play's Sugar Rush, positions where symbols have exploded are marked and can carry multipliers if another win lands there. Reactoonz charges a meter as symbols are removed. The help screen explains each version.

Cluster pays vs paylines vs pay anywhere

Three systems are often confused. The key difference is what the symbols must do to win.

Pay-anywhere games are sometimes marketed as cluster games, but the symbols do not need to touch. Our slot paylines explained guide covers the line-based system in depth, and slot features explained puts all three alongside other mechanics.

Are cluster pays slots high volatility?

Many are. Large prizes need large clusters or long cascade chains, which are rare, so a lot of the return is concentrated in a small share of spins. Of the ten games in the table above, seven carry a high volatility rating from their developers. Gemix is a medium-volatility exception, and TNT Tumble sits at medium–high.

The cluster mechanic itself does not set the RTP; that is fixed by the overall maths, and the cluster games above publish figures between about 96.1% and 96.8%. What changes is the rhythm: frequent small clusters that often return less than the stake, punctuated by the occasional chain. Read our volatility guide and high RTP slots guide before choosing.

How to play cluster pays slots step by step

1. Open the help screen and note the grid size, minimum cluster, whether diagonals count and what the wild does.
2. Check the paytable bands: which cluster sizes return more than your stake for each symbol.
3. Confirm the RTP version and any maximum win cap at your casino.
4. Choose a stake you are comfortable losing in full, remembering UK limits of £5 per spin (25+) or £2 (18–24).
5. Press spin. The game finds clusters, pays them, removes them and cascades until no new wins form.
6. Watch the net position display rather than individual wins to see how the session is really going.

UK rules for cluster pays slots

Cluster games are online slots, so the full slot rulebook applies. Since 31 October 2021 each game cycle has had to last at least 2.5 seconds, autoplay, turbo and slam-stop are banned, and the game must not celebrate a return equal to or less than the stake; the Commission's technical standards summary (opens in a new tab) sets out the wording. Our page on UK slot game design rules explains each one.

A cascade chain is part of the same game cycle as the spin that started it, so it costs one stake and counts once towards the stake limit. The Gambling Commission's stake limit guidance (opens in a new tab) says a game cycle runs until all stakes are lost or all winnings are delivered. The limits are £5 per spin for over-25s (since 9 April 2025) and £2 for 18 to 24-year-olds (since 21 May 2025); see our slot rules hub.

Where to play cluster pays slots in the UK

Cluster games from the major studios are widely available at UK-licensed casinos, and each of our partners lists thousands of games. We have not verified every title in each lobby, so search for the game you want and check its RTP in the help screen.

Here is how the current partner offers relate. Coral Casino (18+, new players, terms apply): deposit with an eligible method, bet £10 on slots and receive 100 free spins at 10p on selected games, to be accepted within 48 hours and used within 7 days, with spin winnings free of wagering. PlayOJO (18+, new UK customers excluding Northern Ireland, terms apply): 80 free spins at 10p on Big Bass Bonanza, a payline slot rather than a cluster game, with a first deposit of £10 or more and cash winnings. Casumo (18+, opt-in, terms apply): 50% of a first deposit of at least £20, up to £100, wagered 10x within 7 days at a maximum of £5 per bet, with game restrictions that may affect which cluster titles count.

Cluster pays slots are entertainment with a built-in cost. Use deposit limits and reality checks, and if you need support, GamCare's National Gambling Helpline (opens in a new tab) is free on 0808 8020 133. More guides are on our guides hub.

18+. Gambling should be entertainment that costs money, not a way to make it. Set a deposit limit before you play: how to set deposit limits. Free, confidential help: National Gambling Helpline 0808 8020 133.