Slot Features Glossary: Wilds, Scatters, Bonus Rounds & More

Slot features glossary: clear definitions of Megaways, cascades, wilds, scatters and more, with free demos to see them in action. No download or registration.

24+ Free Games
0 Cost to Play
15 Studios

Popular Free Slots

View All 24+ Free Slots

Slot Features Glossary: Every Mechanic Explained

Modern online slots come loaded with creative features and bonus mechanics. Whether you are a newcomer trying to understand what "cascading reels" means or an experienced player curious about the latest innovations, this glossary covers every major slot feature you will encounter.

Wild Symbols

Wild symbols substitute for other standard symbols to help complete winning combinations. Think of them as the joker in a deck of cards. Many modern slots include enhanced wild types:

  • Expanding Wilds: Grow to cover an entire reel when they land. Try Starburst for a classic example
  • Sticky Wilds: Remain in place for multiple spins, common in free spin rounds like Dead or Alive 2
  • Walking Wilds: Move across the reels one position per spin
  • Multiplier Wilds: Apply a multiplier (2x, 3x, or more) to any win they help create

Explore more in our wild features slots collection.

Scatter Symbols

Scatter symbols pay regardless of their position on the reels and typically trigger bonus features. Landing 3 or more scatters usually activates free spins. Unlike standard symbols, they do not need to appear on a specific payline. See our scatter symbols guide for details.

Free Spins

Free spins are bonus rounds where you spin without using your balance. They are usually triggered by scatter symbols and often come with enhancements like multipliers, extra wilds, or special symbols. Games like Gonzo’s Quest feature increasing multipliers during free spins, while Book of Dead offers expanding symbols. Browse bonus round slots for the best free spin games.

Multipliers

Multipliers increase your winnings by a specified factor. A 3x multiplier triples any win it applies to. They appear in various forms: base game multipliers, free spin multipliers, and progressive multipliers that increase with consecutive wins (as seen in Gonzo’s Quest).

Cascading Reels (Avalanche/Tumble)

Instead of spinning reels, winning symbols disappear and new ones fall into place, potentially creating chain reactions of wins from a single spin. Gonzo’s Quest pioneered this feature, while Gates of Olympus and Sweet Bonanza use the tumble mechanic with multipliers.

Megaways Mechanic

Created by Big Time Gaming, the Megaways engine randomizes the number of symbols on each reel per spin, offering up to 117,649 ways to win. Top Megaways games include Bonanza Megaways, Extra Chilli Megaways, and Buffalo Rising Megaways. Read our full Megaways slots guide to learn more.

Bonus Buy (Feature Buy)

Some slots let you skip the base game and purchase direct access to the bonus round for a set price, usually 50-100x your bet. This is popular in games from Pragmatic Play and Nolimit City. Explore the bonus buy slots collection.

Hold and Spin / Respin Features

In hold and spin features, special symbols lock in place while the remaining positions respin a set number of times. Landing additional special symbols resets the respin counter. Wolf Gold is a well-known example of this mechanic.

Cluster Pays

Instead of traditional paylines, cluster pays slots award wins when groups of matching symbols connect horizontally or vertically. Reactoonz from Play'n Go is one of the most popular cluster pays games. Explore our cluster pays slots collection.

Gamble Feature

After a win, some slots offer a gamble option where you can risk your winnings on a 50/50 bet (like guessing the color of a card) to double them. This feature is common in games from Play'n Go and NetEnt.

Ready to see these features in action? Play any of our 27,900+ free demo slots to experience them firsthand.

Play Free Slots by Region