Fifteen reels is the target, not the starting grid: Infinity Reels and Infinireels games open on three reels and add one with every win. Seven of them compared on return, top win and how they grow.
Where Fifteen Reels Comes From
No slot in this group starts on fifteen reels. They are Infinity Reels games, a format ReelPlay created, plus NetEnt’s own version called Infinireels: every spin opens on a small three-reel grid, and each winning spin adds another reel on the right. The grid keeps growing for as long as the wins keep coming.
Fifteen is the landmark. On ReelPlay’s games, adding twelve reels to the starting three in one sequence pays the Infinity Bonus of 888x the stake on top of the wins already made. That is why the format is filed under 15 reels, and why every game here also begins life as a 3 reel slot.
The Seven Games That Grow to Fifteen
Listed by the highest return each game offers. Some come in more than one version, so the figure on the game’s own help screen at your casino is the one to go by.
| Game | Studio | Starting grid | RTP | Max win | Volatility |
|---|---|---|---|---|---|
| Secrets of Cleopatra Infinity Reels | PG Soft | 3×4 | 96.74% | – | High |
| El Dorado Infinity Reels | ReelPlay | 3×4 | 95.51% to 96.54% | 6,250x | Medium-high |
| Giza Infinity Reels | ReelPlay | 3×4 | 96.45% | 10,000x | Medium-high |
| Gods of Gold Infinireels | NetEnt | 3×3 | 96.21% | 25,000x | High |
| Thor Infinity Reels | ReelPlay | 3 reels | 96.20% | 6,055x | High |
| Odin Infinity Reels Megaways | ReelPlay | 3 reels, 2 to 5 rows | 96.18% | 20,000x | High |
| West Coast Cash Infinity Reels | ReelPlay | 3×4 | 96.16% | 20,350x | High |
The dash for Secrets of Cleopatra is there because listings split between a 10,000x and a 100,000x top win.
Secrets of Cleopatra Infinity Reels
PG Soft’s first Infinity Reels game has the highest return of the seven at 96.74%, with high volatility. It opens on a 3×4 grid, and its four-tier bonus round lets you gamble for a bigger multiplier step, up to four for every new reel, with a multiplier that does not reset during the round. More pharaoh-era games are on our Egyptian slots page.
El Dorado Infinity Reels
The game that started the format. Its return depends on how you play the free spins, which can be stored or gambled up through levels: 95.51% at the base level and up to 96.54% at the top, where each new reel lifts the multiplier by four. The top win is 6,250x, well above the 888x bonus for reaching fifteen reels.
Giza Infinity Reels
ReelPlay’s Egyptian follow-up returns 96.45% and pays up to 10,000x, at medium-high volatility. Any win that includes a pyramid symbol starts ten free spins.
Gods of Gold Infinireels
NetEnt’s take works on ways instead of a multiplier. It starts as a 3×3 grid with 27 ways, and each added reel triples the count, to 81 ways at four reels and on into the billions. Three scatters bring ten Win Spins, in which each spin is built to land a win. The return is 96.21%, and the 25,000x top win is the largest here.
Thor Infinity Reels
Thor swaps free spins for Jackpot Respins: six or more hammer symbols lock in place for three respins, the count resets whenever a new hammer lands, and special hammers carry jackpots of 10x, 50x, 250x and 2,000x. It returns 96.20% with high volatility and a 6,055x ceiling.
Odin Infinity Reels Megaways
This one adds the Megaways engine, so every reel shows between two and five symbols as well as the grid growing sideways. The free spins have four levels that raise the multiplier step from one to four per new reel. ReelPlay’s own simulations put the top win at 20,000x, with a 96.18% return and high volatility.
West Coast Cash Infinity Reels
A gangster-themed ReelPlay game where wins pay for five or more matching symbols anywhere in view. Three or more Cash symbols trigger Level-Up Re-Spins with four modifier characters. It returns 96.16%, with high volatility and the second-largest ceiling here at 20,350x.
How the Multiplier Climbs With Each Reel
On the ReelPlay games, the win multiplier starts at 1x and goes up by one each time a reel is added. A spin that adds three reels therefore finishes with wins multiplied by four, and the multiplier resets once a spin stops growing. In free spins, higher levels raise the step to two, three or four per reel, which is where the biggest wins come from.
The 888x Infinity Bonus sits outside that maths: it is paid flat for reaching fifteen reels and is not multiplied. Gods of Gold has neither a multiplier nor the 888x prize; its reward for a long chain is the sheer number of ways.
Infinity Reels Against Megaways
Both formats change the grid on every spin, but in different directions. Megaways slots keep a fixed number of reels and change how many symbols each one shows; Infinity Reels keep the rows and add columns. Most Megaways games sit with our 6 reel slots, while an Infinity Reels game can pass six, ten and fifteen reels in a single lucky spin. Odin is the one game here that runs both at once.
Giza, Thor and West Coast Cash sell a bonus buy in some markets. GB versions carry none, so their features start only from the reels.
The Hourly Cost Behind a Growing Grid
El Dorado shows how much the return can move inside one game. Over 600 spins at the £5 limit for players aged 25 and over, an hour averages about £104 at the 96.54% top level and £135 at the 95.51% base level. At the £2 limit for players aged 18 to 24, the same two levels come to roughly £42 and £54 an hour.
Gods of Gold at 96.21% averages about £23 an hour at £1 a spin. With high volatility on most of these games, real sessions swing well above and below those figures, and a free demo at your casino is a no-cost way to watch a grid grow before staking.
