Mermaid Royale Slot by RealTime Gaming

Sitting above reels 2, 3 and 4 is a separate 3-position strip called the Bonus Row. It spins at the same time as the main grid on every single base spin, and nothing that lands in it ever touches the paylines directly. Its whole job is triggering things. Wilds, Treasure Chests, and the gold +4 Free Games Special Scatter only ever appear up there, and each symbol has a different job when it stops. A Wild in the Bonus Row expands downward and turns every position on the reel beneath it into a Wild, giving you an instant 1x3 stacked wild column on the main 5x3 board. Three Treasure Chests filling the strip lock the middle three reels as a 3x3 Oversized symbol while reels 1 and 5 respin three times, and the final payline calculation happens after that third respin.

The Free Games trigger is more elastic than most RTG bonuses. It needs three or more scatters in total, but they can be regular coin scatters on the main grid (each worth +3 spins) or Special Scatters from the Bonus Row (each worth +4 spins plus a Random Booster). Mix and match. Three Specials alone land the full Booster load. A clean three-regular trigger gives you 9 spins with no boosters, which is the tame version. Once the round starts, reels 2-4 merge into a single 3x3 Oversized symbol that spins as one block alongside reels 1 and 5, so almost every spin lands identical symbols across those middle nine positions. That's where the 50,000x top end comes from, a full 3x3 mermaid premium lining up with matching high symbols on the outer reels.

Random Boosters stack up to three at once, drawn from a full Wild stack on reel 5, a x2 multiplier on wins, and doubled Wild chance on the Oversized reel. Retrigger scatters landing in the Bonus Row during Free Games add +1 spin each and activate another Booster if the meter isn't full yet. There's no buy bonus option, no ante bet, and no progressive jackpot sitting on top.

Visually it runs on teal, royal blue and gold. Four mermaid portraits with red, green, blue, and purple hair fill the premium slots, each wearing a tiara, painted in the soft 2022-era RTG house style. The grid sits inside a carved stone archway, Greek pillars and submerged ruins line the edges, and a large stone seahorse curls against the right side. The Bonus Row itself is framed in blue-stone reliefs of dolphins and fish. For a different RTG take on ocean fantasy try Ocean Oddities, or look at Crystal Waters for the same underwater register without the Oversized symbol trick.