Modern slots are packed with features, and the terminology can be confusing. Here’s a clear glossary of the mechanics you’ll meet most often.
Wild
A wild substitutes for other symbols to complete wins. Variations include expanding wilds (fill a whole reel, like Starburst), sticky wilds (stay in place for re-spins) and multiplier wilds.
Scatter
A scatter pays regardless of where it lands and typically triggers bonuses — usually free spins — when enough appear. In scatter-pays slots, scatters drive the whole game.
Multiplier
A multiplier boosts a win by a set amount (2x, 5x, 100x…). In games like Gates of Olympus multipliers stack during free spins, which is where the biggest wins come from.
Free spins
The core bonus round: a set of spins, often with an enhanced feature like extra multipliers or expanding symbols, as in Book of Dead. Triggered by landing scatters.
Tumbling / cascading reels
Winning symbols disappear and new ones fall in, allowing chain wins from a single spin. NetEnt’s Gonzo’s Quest pioneered this as the “Avalanche”.
Megaways
A licensed engine that changes the number of symbols per reel every spin, creating up to 117,649 ways to win. Expect high variance.
Buy feature (bonus buy)
Pay an upfront multiple of your stake to trigger the bonus instantly. Convenient but high-risk — and restricted or banned in several regulated markets. Understand the RTP and volatility before using one.