This is a 5x4 game with 40 fixed paylines, and it uses coins, so it's a bit challenging to set up your bet properly and to read the paytable if you're not used to coins but usually simply place your cash bet. When I finally managed to set up the game to have a €1 total bet, I played it for a few hours in order to be able to write a detailed review of this NetEnt release, so you can choose if it's a slot game you'd like to play for real money or not. Main game and paytable The main game can be more rewarding than you're used to, and Golden Grimoire is therefore a rare slot game that can pay well even during those times when you haven't triggered the free spins feature. When you do trigger it, it will be just a bonus. The paytable is a standard one for slot games that rely on multiple payline wins, and it can only award up to 5x your stake for a single five-of-a-kind win. The other three main symbols pay 3.75x, 2x and 1.5x at best, so that's not a lot either. The four card suit symbols can only bring you your stake back and that's it – at least as far as a single winning payline is concerned. But this slot game has 40, and the symbols are often stacked, so basically whenever you land a win it will be more than one payline. Getting only one is rare. Bonus features There's one main feature with two variations – one is used in the main game and the other is used in the free spins game. In the main game, Mystery Symbol feature will get triggered whenever the Mystery Symbol lands on your reels, and it can land on reels 3, 4 and 5. After that, a random symbol will be chosen, and it can be a Wild – in fact, that's the only way to land a Wild. If the transformed symbol matches the first symbol in the respective row, then all the symbols in between will also be transformed, and if the transformed symbol is a Wild then all the symbols in between will definitely be transformed to Wild regardless of which symbol is on reel 1. In the free spins game, which you trigger when you land all three Scatters that appear only on reels 1, 3, 5, you'll get the Sticky Mystery Symbol that can stick for the duration of your 8 free spins. The obvious difference is, the Sticky Mystery Symbol will stick until you got no more spins, and with each spin it will transform in a new symbol. This makes a huge difference compared to the main game, and the free spins game can therefore be very rewarding, depending on your luck with the transformed symbols, of course. Golden Grimoire Slots RTP Theoretical return to player (RTP) of Golden Grimoire is 96.44%, which means that it's in line with modern standards, but isn't a particularly loose slot. It's alright. Variance is low and the game has a way of keeping your balance positive for a long time, so you'll actually feel as if the game is paying really well. Conclusion Golden Grimoire is a really good slot game that should be played for real money, as it's a low-risk gambling experience that won't hurt at all. Simply enjoy this game for what it is, and it will reward you with constant small wins that will keep your bank balance healthy. There's also a chance of landing a bigger win, though that win isn't life-changing, but overall this is a good way to pass the time while having a chance to win some money.