Megaways and cluster pays: what the mechanic changes about a spin

Three mechanics are competing for the same lobby space: fixed paylines, the variable-height reels sold as ways to win, and cluster pays. We take them in turn and keep asking one question of each — what does this change about the stake you just put down? The answer is never the return, and that is the part the marketing relies on nobody checking.

Three definitions of a win

A payline game draws a fixed number of paths across the reels. A win is matching symbols sitting on one of those paths, counted from the leftmost reel, and the number of paths is a constant: ten, twenty, twenty-five, whatever the game declares.

A ways-to-win game drops the paths. Each reel shows a variable number of symbols on each spin, and a win is any matching symbol on every consecutive reel from the left, in any row. The number of combinations is therefore recalculated every spin: it is the heights of the reels multiplied together.

A cluster-pays game drops the left-to-right rule as well. A win is a group of matching symbols touching each other anywhere on the grid, usually above a minimum size, and the pay rises with the size of the group rather than with the length of a line.

What 117,649 is counting

The headline number on the best-known ways engine is 117,649, and it is seven to the sixth power: six reels, each showing up to seven symbols. It is a ceiling, reached only on the spin where all six reels come in at full height, which is not a common spin. Two symbols on each of the six reels is two to the sixth, which is 64 ways. Four on each is 4,096. The same game, the same stake, three orders of magnitude between them.

Reel heights on this spin	Ways available
2 symbols on each of six reels	64
4 symbols on each of six reels	4,096
6 symbols on each of six reels	46,656
7 symbols on each of six reels	117,649

None of which tells you anything about your chances, for the reason set out below: the ways are the denominator and the paytable is the numerator, and the studio sets the second one after it has counted the first.

The paytable absorbs the mechanic

A game is designed to a target return. Whatever the mechanic does to the number of winning combinations, the pays are scaled so the total comes out at the figure on the information screen. More ways means each way is worth less: a five-symbol line that pays 50 times stake on a twenty-line game cannot pay 50 times on an engine where the same symbols can land in thousands of positions at once.

So the comparison that is sometimes made — “117,649 ways versus 20 paylines, therefore better odds” — is comparing a count of combinations with a count of combinations and ignoring the price of each one. The stake is per spin in every case. Our conversion of edge into return holds unchanged across all three mechanics, because it is a statement about the money and not about the geometry.

What actually changes

Mechanic	What one stake buys	What the results look like
Fixed paylines	one resolution across a fixed set of paths	steadiest of the three; pays are predictable from the paytable
Ways to win	one resolution across a count that changes every spin	uneven by construction — low-height spins can barely pay, tall ones pay in several directions at once
Cluster pays	one resolution, usually plus the cascades it triggers	wins arrive in chains; a single stake can resolve six or seven times

The cascade line is the one with a practical consequence. When symbols in a winning group are removed and replaced, one stake is resolved repeatedly, and the balance moves several times for one button press. Nothing about the return changes, but the pace does, and pace is what turns a stated return into an hourly cost: the faster the resolutions, the more of your money passes through the game per hour, and the expected loss is a percentage of exactly that. The same arithmetic applies to the spin count in five hundred spins at a stated return of 96.5 per cent.

Reading one of these games before you stake

Three things on the information screen settle it. The stated return, which is the only figure comparable across mechanics. The maximum win multiplier, which tells you how much of that return is parked in rare events — and on ways and cluster engines it is usually parked very deep, which is why they read as high-band games on the test in where a slot shows its volatility. And the minimum cluster size or the minimum reel height, which is the number that decides how often the grid can pay at all. Everything after that is theme.