Slot Bonus Features Explained

Wild Symbols

A wild symbol substitutes for any regular symbol to complete a winning combination. If you have two matching symbols on a payline and a wild lands between them, the wild completes the win.

Expanding wilds: A wild that expands to cover the entire reel — dramatically increasing win potential on that spin.

Sticky wilds: A wild that stays in position for multiple subsequent spins. Common in free spins rounds.

Walking wilds: A wild that moves one position per spin — shifts left or right across the reels during a sequence of spins.

Multiplier wilds: A wild that multiplies any win it contributes to — common values are ×2, ×3, up to ×5.

Scatter Symbols

Scatter symbols pay regardless of payline — they just need to appear on the reels, anywhere, in sufficient quantity. Usually 3+ scatters trigger the free spins bonus round.

Scatters don't need to be on the same payline or consecutive reels. This makes them visually exciting — any scatter appearance is a potential trigger.

Some scatters multiply your total bet stake on top of triggering the bonus. A scatter pay of 2× your total bet for 3 scatters is a common structure.

Free Spins Bonus Rounds

The free spins bonus is the most common and most valuable slot feature. You get a set number of spins (usually 8–25) with enhanced mechanics — extra wilds, multipliers, guaranteed payouts, or all three.

Key things to check:
- Can the bonus re-trigger? (landing more scatters during free spins)
- Are there multipliers that increase with each spin?
- What is the max multiplier possible?
- What RTP does the slot have specifically during free spins?

For high-variance slots like Money Train 4 or Dog House Megaways, virtually all the RTP is packed into the bonus round — base game returns are minimal.

Multipliers

Multipliers increase the value of wins by a fixed or variable amount. Types:

Fixed multiplier: Every win in the bonus pays ×3 (or ×5, ×10, etc.)

Progressive multiplier: Increases by 1 with each winning spin during the bonus — starts at ×1, rises to potentially ×50 or higher in top titles.

Cascading multiplier: Each cascade (chain of wins) increases the multiplier — popular in Gates of Olympus and Sweet Bonanza.

Random multiplier: Lightning Roulette's 'lightning' mechanic applies a random multiplier (×50 to ×500) to selected numbers each round.

Buy Feature (Bonus Buy)

The bonus buy feature lets you purchase the free spins round directly, bypassing the need to land scatters organically. Typical cost: 80–100× your stake.

This is mathematically equivalent to a large number of base game spins — you're paying for the expected RNG cost of triggering the bonus. It doesn't improve your odds — it only speeds up the experience.

Important: Most casinos disable bonus buy when you have an active deposit bonus. Check bonus terms before using this feature.

Tumble / Avalanche / Cascade Reels

Winning symbols disappear ('tumble') and new symbols fall into their place — potentially creating a chain reaction of wins from a single spin.

Gates of Olympus, Sweet Bonanza, and Gonzo's Quest use this mechanic. Each cascade typically increases a multiplier, meaning a single spin with multiple cascades can produce outsized wins. The cascades stop when no new winning combination forms.

Megaways

Megaways is a Big Time Gaming (BTG) mechanic that randomly varies reel height (2–7 symbols per reel) on every spin, creating up to 117,649 ways to win. Wins pay on any adjacent symbols from left to right — no fixed paylines.

Many providers licence Megaways from BTG, including Pragmatic Play (Dog House Megaways) and Red Tiger (Gonzo's Quest Megaways). See our full Megaways slots guide for details.