Book of Power follows convention by employing 10 fixed paylines for successful combinations. Five of the pay symbol categories are 10-A card royals, while the four high-paying symbols are three Ancient Egyptian symbols and an explorer as the most valuable. A successful line consisting of five matching symbols pays between 1 and 10 times the wager for low pays and 75 to 500 times the wager for premiums.
The appearance of 3, 4, or 5 Book symbols awards 10, 15, or 20 free spins in addition to payouts of 10x, 100x, or 500x the wager. At the beginning of the round, a pay symbol is chosen to be the special expanding symbol. During free spins, expanding symbols expand to cover all positions on their reels, paying all ways from any position, in addition to normal line winnings. If two Book symbols appear during free spins, an additional expanding symbol and five additional free spins are awarded. If the new random symbol is already an active expanding symbol, its multiplier is increased by 1 up to a maximum of 9.
If one of the 3, 4, or 5 Book symbols that activate Power Free Spins is a Power Book symbol, the player receives 10, 15, or 20 Power Free Spins and a payout of 10x, 100x, or 500x the wager, respectively. In the Power Free Spins feature, a special expanding symbol is chosen at random that expands to encompass the reels and pays all ways from any position, as stated previously. When 2 Book symbols appear, the expanding symbol is upgraded by one level and 5 additional free spins are awarded. If the highest-paying symbol is reached, any subsequent retriggers award a +1 multiplier for the expanded symbol, up to a maximum of 9. In addition, landing a Power Book on reels 2, 3, or 4 transforms that reel into a golden one in which the expanding symbol expands even if no expanding symbol landed on that reel.