Kingdom Wardens

The Special Expanding Symbol is one of the most iconic and popular mechanisms in online slot history, a core free spins feature primarily found in 'Book of...' series games. The essence of this feature is that one regular symbol, randomly selected at the start of the free spins, gains a special power. This symbol, as long as it appears on the reels in the required number to form a win, will expand to cover its entire reel and create massive wins regardless of its position.

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.