Book of 99

Book of 99 by Relax Gaming holds the crown as one of the highest RTP slots ever made at 99%. This 5-reel, 10-payline adventure slot uses Book mechanics where special symbols expand across entire reels during free spins. The game collects golden book pages during base play. Once you gather 99 pages, you trigger the free spins bonus round. Volatility is very high, meaning wins come in bursts rather than steady trickles, but the extraordinary RTP means the math heavily favours longer sessions. Max win potential sits at 5,000x your stake. The expanding symbol mechanic during free spins can fill entire reels, creating massive multi-line wins. Relax Gaming built a visual page counter into the interface, so you track your progress toward the bonus in real time. The visual design draws from ancient manuscript themes with rich colours and smooth animations. For Canadian players searching for the best payout percentages, Book of 99 is the gold standard. If you prioritise return-to-player percentage above all else, this slot belongs at the top of your list.