Cluster Pays Slots: Top Games & Casino Picks

Cluster slots, also known as ‘grid slots’ and ‘cluster pays slots’, are a popular and innovative type of online casino slot machine games. They were first introduced by NetEnt in their slot, Aloha: Cluster Pays, in May 2016. These slots deviate from the traditional 10 or 15 payline structure, instead paying out when symbols appear in clusters.

Different Types of Slot Games

Before exploring Cluster Pays, take a look at the seven different types of online slot games below to compare their features and gameplay mechanics.

Bonus Buy Slots
Unlock special game features instantly by paying a set amount, often 100x your wager.
Branded Slots
Movie or pop culture-themed slots featuring recognizable characters or storylines.
Classic Slots
Vintage-style slots featuring 3 rows, up to 5 reels, and a lack of complex bonus games.
Cluster Pays Slots
Group together similar symbols horizontally or vertically for a win.
Jackpot Slots
Slot games with prizes that can either grow progressively or remain static.
Megaways Slots
Dynamic reel system featuring shifting symbols and a changing number of paylines.
Video Slots
Online slots with 5-7 reels and a host of paylines, including 5-15 bonus free spins.

Popular Slots with Cluster Pays Mechanics

Cluster SlotProviderRTP
5 MonstersRelax Gaming96.4%
Buster’s BonesNetEnt96.1%
Chain Reactors DeluxeLight & Wonder96.0%
Champions of OlympusGold Coin Studios96.1%
Celestial BeautySkywind96.5%
Jelly MultihopsRed Tiger Gaming96.2%
Jiggly CashThunderkick96.5%
Viking Fury SpinfinityBlueprint Gaming96.0%
Viking Runecraft ApocalypsePlay’n GO96.0%
Wildman Super BonanzaPragmatic Play96.6%

Key Features of Cluster Pays Slots

Cluster slots typically feature a grid format, where symbols are arranged in 8 or more rows and 5 or 6 columns. To win, you need to form clusters of matching pay symbols, either horizontally or vertically (see image).

Cluster Pays Slot "Retro Tapes" by Push Gaming
Cluster Pays Slot “Retro Tapes” by Push Gaming

The minimum number of symbols required for a win varies depending on the game, but it generally ranges from 4 to 6.

Volatility and Return to Player (RTP)

Just like most other European slot games, cluster slots have 3 levels of volatility, ranging from low to high. This means that some cluster slots may offer more frequent but smaller payouts (low volatility), while others may provide less frequent but larger payouts (high volatility). The return to player (RTP) also varies among all cluster and grid-type slots, with some games featuring higher RTPs than others. The average RTP across the listed newest cluster pay slots is 96.14%.

This is calculated by summing up all the individual RTP percentages of the slots and then dividing this sum by the total number of slots. The individual RTPs are as follows:

  • 5 Monsters: 96.4%
  • Buster’s Bones: 96.1%
  • Chain Reactors Deluxe: 96.0%
  • Champions of Olympus: 96.1%
  • Celestial Beauty: 96.5%
  • Jelly Multihops: 96.2%
  • Jiggly Cash: 96.5%
  • Viking Fury Spinfinity: 96.0%
  • Viking Runecraft Apocalypse: 96.0%
  • Wildman Super Bonanza: 96.6%

As there are 10 slots, we divide this sum by 10: 961.4 / 10 = 96.14%.

  • Tip: Consider both volatility and RTP when choosing the best cluster pays slots with high payouts. An RTP of 96% is generally considered optimal.

Cluster Wins and Cascading Reels

One of the main attractions of grid-type cluster slots is the cluster win mechanic, which allows players to win by forming clusters of matching symbols. This is further enhanced by the cascading reels feature, where non-winning symbols are removed from the grid, and new symbols drop into place, potentially creating additional wins on top of excisting ones.

The tumbling feature can lead to multiple consecutive wins.

Special Symbols and Features

All grid cluster pays slot games include various special symbols and extra in-game features to make the gameplay more interesting. Some common elements found in cluster slots are:

  • Scatters trigger bonus rounds or free spins when they drop in the required amount, usually three;
  • Wild Symbols substitute for any other symbols, except scatters, to form winning clusters;
  • Multipliers increase the payout of winning clusters if they drop next to them;
  • Sticky Wilds remain in position until no more wins occur or during an entire bonus round;
  • Expanding Symbols cover multiple grid positions both vertically and horizontally, enabling more chances to win.

Bonus Rounds and Free Spins

Popular cluster slots also feature bonus rounds and free spins, which can be triggered by specific symbols or conditions. These bonus features often include sticky wilds, extra wilds, boosted multipliers, transforming symbols, chain reactions, additional free spins, or other gameplay enhancements.

Some cluster slots, like Good Luck Clusterbuster Jackpot by Red Tiger, also offer progressive jackpots, where a portion of each bet contributes to a growing jackpot prize.

These jackpot prizes can be won by meeting specific game conditions or triggering a random special bonus round.

Mobile Compatibility and User Interface

Today, most of the content available on desktop computers is undoubtedly available on mobile devices. Consequently, all the newest cluster and Megacluster slots that you can find in the table above are designed with mobile compatibility in mind.

Cluster Pays Slots Worth a Spin

Retro Tapes by Push Gaming is our favoured cluster pays slot game that rewards by forming clusters of similar symbols.

FeatureDescription
Maximum Win (Observed & Theoretical)10,000x
RTP96.47%, 94.46%
VolatilityHigh
Bonus BuyAvailable
Wild Multiplier SymbolAvailable in Base Game and Top Charts Feature
Magnet FeaturePicks a Paying Symbol and forms a cluster
Top Chart FeatureLands random symbols during Free Spins
Cluster Links FeatureForms clusters for instant wins
Instant Prize SymbolsValues: 1x, 2x, 5x, 10x, 25x, 50x, 100x, 250x, 500x, 1000x

The game features a retro theme and has special components like the Wild Tape Symbols and the Tapes & Instant Prize feature. The Wild Tape Symbols substitute for other symbols (except Magnet and Wild Multiplier Symbols), and increase their multiplier value each time they contribute to a win.

Three or more Wild Tape Symbols trigger the Free Games Feature. In the Tapes & Instant Prize feature, tape clusters yield instant wins based on the tape symbol value and the cluster type. The Instant Prize Symbols act as bet multipliers, and the Wild Multiplier Symbol not only boosts winnings but transforms into an Instant Prize Symbol after awarding its multiplier.

Both can happen during both the base game and the Top Charts Bonus, improving the game’s winning potential. Retro Tapes has also three special bonus features: the Magnet Feature, the Top Charts Feature, and the Cluster Links Feature.

Retro Tapes has two RTP percentages: 96.47% and 94.46%. And the game’s maximum win, both theoretically and observed, is 10,000x. As a high volatility cluster slot game, Retro Tapes has less frequent payouts, with possible large wins when they do occur.

There is also an in-built “bonus buy” option similar to other feature buy slot games available (see image below), providing a quick opportunity to buy a free spin bonus game instead of waiting to trigger it during gameplay naturally.

Cluster Pays Slot Bonus Buy Feature

For more detailed insights, watch our YouTube video showing Retro Tapes gameplay.

Top Casinos to Play Cluster Pays Slots

Iconic online slot games with cluster pay mechanics, like Reactoons, Jamin’ Jars, Sweet Bonanza, and Sugar Rush, are popular choices among many gaming enthusiasts.

Among the top casinos offering these games are several EU casinos such as Bitstarz, Winz, CasinoFriday, Mount Gold, SlotVibe, and others.

These casinos offer a broad range of casino games and are recognized for their varying features, like deposit bonuses, game providers, support services, and convenient payment methods.

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Cluster Pays Slots Questions and Answers

What exactly are cluster pays slots?
Cluster pays slots, also known as ‘grid slots’ or ‘cluster-based slots’, feature a unique gameplay mechanic where you form winning combinations via clusters of matching symbols. Unlike traditional slots based on paylines, these games pay out when identical symbols are adjacent to each other in a cluster of five or more, either horizontally or vertically.
How is the grid format structured in cluster pays slots?
The grid in cluster pays slots is usually structured with 5-10 rows and 5 or 6 columns.
What does the volatility in cluster pays slots mean?
Volatility represents the level of risk in cluster pays slots. Low volatility results in frequent but smaller wins, medium volatility offers a balanced frequency and size of wins, and high volatility leads to less frequent but potentially larger wins.
What is the average RTP in cluster pays slots?
The average return-to-player (RTP) in cluster pays slots is 96.14%, based on real data.
What is the cluster win mechanic and cascading reels feature?
The cluster win mechanic replaces traditional paylines with clusters of 5 or more identical symbols for a win. The cascading reels feature—also known as tumbling reels or the avalanche feature—causes winning symbols to vanish, making room for new symbols to fall into place. This can create additional wins and the process can repeat, allowing for multiple wins in a single spin.
What are some cluster pays slots’ special symbols and features?
Special symbols and features in cluster pays slots include scatter symbols that activate bonus rounds, wild symbols that replace other symbols for wins, multipliers, sticky wilds, expanding symbols, and more unique elements to enhance gameplay.
How do cluster pays slots bonuses and free spins work?
Bonuses and free spins in cluster pays slots are usually activated by special symbols or specific conditions. These bonus features can come with enhancements like higher multipliers, additional wilds, transforming symbols, or chain reactions for successive wins. Some even feature progressive jackpots.
What are some popular themes in grid slots?
Cluster pays slots come in various themes, from fantastical worlds to mythology and retro styles. These themes often feature eye-catching designs, captivating soundtracks, and high-quality graphics.
What other types of online slots are there besides cluster pays?
Besides cluster pays slots, other popular online slots types include video slots, classic slots, jackpot slots, megaways slots, mobile slots, branded slots, 3D slots, i-slots, and VR slots. If you’re interested in diversifying your playing experience, you can explore a variety of casino games available.