Collapsed Castle Bonus Buy Slot by Evoplay

Crumbled stone archways in deep teal and purple hold a shaped grid against a backdrop of misty mountain ruins - the kind of frozen-in-time castle setting where everything glows faintly blue. The grid is unusual: outer reels run three rows, inner reels run four, creating a diamond-ish silhouette that gives 18 paylines instead of the typical 20 or 25.

Symbols tumble in from above. Wins explode, new symbols drop, and chains keep going until nothing connects. Standard cascade stuff, but the Magician symbol - a green hooded figure - makes each chain worth tracking. When a Magician lands and participates in a win, it reveals +2, +5, +10, or +25 and dumps that into a purple orb sitting left of the grid. Every win after that, within the same cascade sequence, gets multiplied by the new total. Base game resets the orb to 1x after each spin.

Free spins change one rule: the multiplier never resets. Ten spins, and the orb just keeps climbing. A +10 Magician in spin 3 that pushed the multiplier to 18x is still there in spin 9. A +25 landing late, when it's already at 30x or 40x, recalculates everything that follows. For 39x total bet, the buy bonus skips straight to those ten spins.

This is the Bonus Buy variant of Collapsed Castle - identical mechanics, just with the purchase option added. Scatters only land on reels 1, 3, and 5, so triggering naturally takes patience on a shaped grid where those reels are the short ones at three rows each.