A feature that transforms low-value symbols into higher-value ones, progressively increasing the average payout potential of the reels.

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.