Book of the Golden Buffalo Slot by Zillion Games

Land six golden bonus coins and the reels lock into the Hold and Ring round. Every coin you catch sticks to its position and the empty slots respin, with each fresh coin resetting the respin counter. When the round closes you collect the combined value of every coin on the grid. Fill all 15 positions across the 5x3 layout and the Grand pays at 1000x. A mystery symbol floats through this mode too, and it can resolve into any tier except the Grand, so it caps out at the Major below it.

The four jackpot plaques sit in a row above the reels and stay fixed: Grand at 1000x, Major at 100x, Minor at 30x, Mini at 24x your bet. They feed only from the coin round, never the base spins, which is why the base game runs lean between triggers. High volatility means long quiet stretches punctuated by the coin feature doing the heavy lifting toward that 1,675x cap.

The other route is the book mechanic. Three book scatters open the free spins round, and before it starts one symbol is chosen at random to expand. When that symbol lands during the round it stretches to cover its whole reel and pays from any position, not just along the 25 lines. A second blue buffalo book joins as a special wild inside this mode, while the gold buffalo book stays wild throughout and also acts as the trigger. Accumulated symbols carry over between spins here, so a strong expanding pick can build across the round rather than resolving on a single hit.

One small extra sits in the base game: line up a full five-of-a-kind across an entire payline and a dedicated celebration pop-up fires. There is no bonus buy, so both feature routes have to land naturally. Visually it leans hard into the American frontier at night. A glowing golden bison stands guard on the left edge, the reels sit against a moonlit desert of cacti and distant mesas under a deep blue sky, and the symbol set runs through hand-painted wildlife, a wolf, a russet cougar, a blue-toned bison, alongside gold-outlined card royals. The round bonus coins drop in stamped with their cash values, a clear tell that the buffalo coin chase is on.