Cascading reels — also called tumble, avalanche or cascade — replace winning symbols with new ones that drop in, so a single spin can produce several consecutive wins.
Why players love them
Many cascade slots increase a multiplier with each chain win, so a lucky sequence can build a huge payout from one bet. The mechanic powers popular titles in the "sweet" and "candy" genres. Cascades add excitement but volatility is usually medium-to-high, so manage your bankroll accordingly.