This is our own slot rating based on how popular the slot is, RTP (Return To Player) and Big Win potential.
Play the Book of Secrets Extra free demo slot—no download required! Try Synot’s latest game, enjoy risk-free gameplay, explore features, and learn game strategies while playing responsibly. Read our expert Book of Secrets Extra slot review with ratings for key insights before you play.
Released:October 5 2022
Responsible Gaming
You have to be 18 years or older to play our demo games. Please confirm that you are of the legal age to proceed:
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Book of Secrets Extra is a video slot experience created by the provider Synot. In this Book of Secrets Extra slot review you’ll learn about its core features (including RTP, max win, and volatility), the bonus mechanics, and what helps the game stand out — along with the areas where it may fall short.
Book of Secrets Extra is played on a 5 reel layout with up to 10 paylines/ways. The game includes a variety of features such as Buy Feature, Expanding Symbols, Gamble, Retrigger, Scatter Pays, Special Symbol, Wilds, and more. There’s also a dedicated free spins bonus round, which is typically where the game’s biggest win potential comes into play.
The standard RTP (Return to Player) for Book of Secrets Extra slot is 95.18% (Could be lower on some sites). This payback is good and considered to be about average for an online slot. Theoretically, this means that for every €100 put into the game, the expected payout would be €95.18. However, the RTP is calculated on millions of spins, which means that the output for each spin is always random.
The highest possible payout for this slot is 5000x your total bet which is pretty high and gives you the chance to win quite big wins. The maximum possible win is also calculated over a huge amount of spins, often one billion spins.
Book of Secrets Extra is a volatile slot, and Synot rates the volatility High (4/5). Volatility, in the context of slot games, refers to how often and how much a slot game pays out. Book of Secrets Extra is designed to appeal to those who enjoy the adrenaline rush of substantial winnings that low volatility slots can't deliver, and are willing to accept the inherent risks of less frequent payouts.
Book of Secrets Extra was released on October 5 2022.
This is our own slot rating based on how popular the slot is, RTP (Return To Player) and Big Win potential.
Yes! You can enjoy Book of Secrets Extra in demo mode without signing up. Try our free version above to explore the features. For real money play, visit one of our recommended Synot casinos.
To play for real money:
Yes. Book of Secrets Extra is powered by Synot, a licensed provider that uses certified RNG (Random Number Generator) technology to ensure fair and unpredictable outcomes.
The slot offers a moderate max win of 5000x your stake.
Example: A €1 bet could return up to €5000.
Yes! Most of our featured Synot casinos on this page offer welcome packages that include free spins or bonus cash usable on Book of Secrets Extra. Always check the terms before claiming.
Absolutely. The game is fully optimized for mobile devices, including iOS and Android.
Yes, many crypto‑friendly casinos offer Book of Secrets Extra as long as they support games from Synot. You can usually play using popular cryptocurrencies like Bitcoin, Ethereum, or Litecoin. If you prefer crypto gaming, check out our list of trusted Bitcoin casinos to find platforms that accept digital currencies and feature Synot slots.
Yes, the demo mirrors the full version in gameplay, features, and visuals—just without real money payouts.
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