The main wild symbol is the book. It will substitute for all of the other symbols, except for the Book and Snake combination symbol, to help and form winning combinations. The second wild symbol is the Book and Snake combination and it will substitute for all of the other symbols except for the Book.
Both the Book and the Book and Snake combination symbols are scatter symbols. They both offer scatter payouts and can trigger the free spins.
If you land at least three of the Book symbols anywhere on the reels then you will win 10 free spins. If one of the three triggering symbols is the Book and Snake then all your winnings during the free spins will be tripled!
Before the free spins begin, one of the symbols is chosen at random to become an expanding symbol. After each spin, once you have been paid out for regular wins, the symbol will then expand to fill its reel if it will form more wins, and you will receive any additional payouts. Best of all, the free spins can be retriggered indefinitely.
Book of Kings offers a top payout of 500 times the bet for landing five explorer symbols on a payline. The Pharaoh can payout up to 200 times the bet, and both the Eye or Ra and the Horus sign can payout up to 75 times the bet. A and K can both payout up to 15 times the bet while Q, J and 10 can all payout up to 10 times the bet. Scatter payouts of up to 200 times the bet are also available for landing five of either of the wild/scatter symbols anywhere on the reels.