Rainbow Riches Free Spins Slot by Light & Wonder

The trick at the heart of this one happens during the bonus, so start there. The blue Free Spins disc lands only on reels one, three and five, and it sits stacked on that first reel. Get one showing on all three of those reels at once and the round opens. How many you can see stacked on reel one sets the award: 10, 15 or 20 spins. Then the reels swap to an alternate set, and the bonus disc changes job entirely. For the duration of the free spins it also counts as a wild, filling in for every paying symbol on the grid. That double role is what separates this entry from the rest of the Rainbow Riches machines, where the bonus icon does nothing but trigger.

The pay per line stays locked to whatever you triggered on, and the round can retrigger the same way, landing the disc on reels one, three and five again to top up the count. There's a hard ceiling of 999 spins, which you'll basically never reach, but it's there. The ornate green-and-red Rainbow Riches logo is the regular wild and turns up on every reel in the base game. It stands in for everything except the bonus disc, so it can finish card combinations but never short-circuit the free-spin trigger itself.

Visually it's old Barcrest through and through. The 5x3 grid sits inside a woven-gold Celtic border, the card values carved in chunky stone in purple, gold, green, blue and red, and a deep purple sky behind it carries a rainbow arcing toward a treasure-chest pot of gold. A grinning green-suited leprechaun leans in at the left edge by the payline arrows, cheering each spin in that bright pub-fruit-machine style Light & Wonder inherited from the original Scientific Games cabinets. It's unmistakably Irish-luck kitsch, and the whole thing hangs on that one bonus where the trigger symbol turns wild.