Slots with Expanding Symbol Feature – Dynamic Wins Across the Reels
The Expanding Symbol feature represents one of the most engaging mechanics in online slots, where designated symbols expand to cover entire reels, dramatically increasing win potential. This feature gained massive popularity after the release of Play’n GO’s Book of Dead, inspiring numerous variations across the industry.
When triggered, expanding symbols stretch vertically to fill all positions on their respective reels. Uniquely, these symbols don’t need to appear on adjacent reels to form winning combinations – they pay on selected lines regardless of position, creating opportunities for multiple wins from a single spin.
Modern slots have evolved this mechanic in several innovative ways:
- Both-ways expansion – symbols expand not only vertically but horizontally, covering multiple reels at once
- Selective expansion – only specific high-value symbols receive the expanding property
- Progressive expansion – symbols gradually expand over several spins, building anticipation
Notable examples of slots utilizing this feature include Book of Ra Deluxe by Novomatic, Legacy of Dead by Play’n GO, and Book of 99 by Relax Gaming. The mechanic is particularly prevalent in “book-style” slots, where it typically activates during free spins rounds with a randomly selected special expanding symbol.
