Triple Gem Treasure

Symbol Upgrade is a powerful feature that progressively converts low-value symbols on the reels into higher-value ones as the game proceeds. The core of this feature is not just a one-time symbol change, but a 'growth' structure where lower-tier symbols are permanently removed from the reels and replaced by higher-tier ones. This drastically increases the average expected payout of the reels towards the end of the round.

Reel Expansion is a feature where the physical size of the game grid (reels or rows) actually gets bigger, typically upon entering a bonus round like free spins. This goes beyond simply adding a multiplier; it aims to expand the 'board' of the game itself, providing players with a wider field of opportunity and fundamentally increasing the number of winning ways.