There are three wild symbols, bronze, silver and gold bars. They can land on the middle three reels and will substitute for all of the other symbols to help and form winning combinations.
The red crystals are the scatter symbol and in addition to offering scatter payouts, they are the key to the bonus feature.
If you land three, four or five of the crystal scatter symbols then you will win 10, 15 or 20 free spins respectively. During the free spins the wild symbols can award huge payout multipliers to increase your winnings. The bronze wild will multiply wins by 2x when it lands on the second reel, the silver wild will multiply wins by 3x when it lands on the third reel, and the gold wild will multiply wins by 5x when it lands on the fourth reel. If more than one wild symbol contributes to a win then the multipliers are multiplied together, this means that it is possible to win multipliers of up to 30x.
The Alchemist’s Spell offers a huge top payout of 166 times your total bet when five of the alchemist symbols land across the reels. The scroll can payout up to 83 times your total bet, the chemicals up to 33 times your total bet and the book up to 25x your total bet. The scatter symbol also offers payouts of up to 50 your total bet for a spin.