Cascading reels — also called tumbling reels, avalanches or a drop mechanic — remove the symbols that formed a win and let new symbols fall into the gaps. If the new symbols form another win, the process repeats. A single paid spin can therefore resolve into a run of consecutive wins.
The multiplier hook
Many cascade games raise a multiplier with each successive drop in a chain. This is where the big results come from, and it is why cascades are common in high-volatility titles. The excitement is real; the RTP is still fixed and still below 100%.
Two ways a cascade multiplier can work
The name on the button — Avalanche, Tumble, Reaction, Free Falls — tells you the studio, not the maths. What matters is how the multiplier is built, and there are two designs:
- Counted per drop. The multiplier steps up with each consecutive win in the chain and resets on the next paid spin. Gonzo's Quest (NetEnt, 2010), the game that made the mechanic famous, runs 1×, 2×, 3×, 5× in the base game and 3×, 6×, 9×, 15× in its free-falls round. The ceiling is reached only by a long unbroken chain, so most of the return sits in short chains at the low steps.
- Collected from symbols. The multiplier is not the chain length at all. In Gates of Olympus the orbs that land carry values from 2× to 500×; at the end of a tumble sequence every orb on screen is added together and applied to the whole sequence's win. A single spin can therefore carry a huge multiplier with a short chain, which is why that game's ceiling is far above Gonzo's despite the same basic drop.
Read the paytable for which of the two you are playing. In the first design the multiplier resets every spin by definition; in the second, a bonus round often keeps a running total across all the free spins, and that accumulation is where the advertised maximum comes from.
Reading it honestly
A long cascade is memorable, but it is priced into the game like everything else. Over sustained play the house edge applies unchanged. Treat a big chain as a good session, not a strategy.