Hawaiian Tiki Slot by PG Soft

The diamond-shaped grid - three rows on the outer reels widening to five rows in the center - isn't just cosmetic. Wilds only land on reels 3 and 4, the two tallest columns with five positions each, and that's where the expanding Wild mechanic plays out. After any winning cascade, Wilds on those center reels stick in place and grow. A new Wild appears directly below the bottommost existing one, or above the topmost if there's no room below. One Wild becomes two, two becomes three, building toward a full column of five.

Once a reel hits five Wilds - a complete column - they all clear on the next round and the growth resets to zero. So the cycle is always pushing toward a peak: you want long cascade chains that stack Wilds up to four on a reel, ideally on both center columns at once, before the fifth triggers the wipe. Four Wilds across two center reels covering 8 of the 10 tallest positions is the sweet spot. Getting there in base game is rare since the expansion resets every time the cascade chain breaks, but that's what free spins fix.

Three scatters award 12 free spins, with 2 extra per additional scatter. The key difference: Wild expansion carries between individual free spins during the bonus. If a spin ends with three Wilds stacked on reel 3, the next free spin starts with those three still there, plus a fourth added automatically. The growth doesn't reset when the cascade chain stops - it persists and keeps climbing spin after spin. That persistence is what makes the bonus round substantially different from base game, not just a reskinned version of the same mechanic.

Landing 2 Free Spin symbols during the bonus adds 4 more spins, and retriggering is possible. No buy bonus option, no multipliers anywhere in the math, no progressive jackpot. The 3,600 ways across that diamond layout and the expanding Wild cycle are the only moving parts. PG Soft lists 2,500x as the cap, though simulated testing across a billion spins peaked at 1,274x - so the tiki statue's blessing has practical limits.