King of Kings Slot by Relax Gaming

The reels sit inside a torch-lit pharaonic temple, with sandstone columns, hieroglyph carvings and the gold-blue-red palette anyone who has spun a Book of Ra clone will recognise instantly. Bastet, Horus, the pharaoh's mask and Anubis loom over a 5x3 grid that runs on just five paylines - low line count, brutal high volatility, exactly the framework these classic Egyptian games were built on.

The Wild and Scatter share one symbol. Three or more anywhere triggers 10 free spins, and this is where the game pivots: a sixth reel slides in to give you a 6x3 layout, and one random symbol gets picked as the special expander. From that moment the special pays as a scatter from any position, and whenever it lands enough copies on a reel it stretches to fill the entire column. Big premiums - the pharaoh, Anubis, Ra - chosen as your expander can paint a full reel and turn one line hit into the per-line cap of 2,000x. Pick a low card royal and you'll feel it. Retriggers are possible, so the bonus has room to compound.

Outside the bonus there's no buy option and no respin gimmick. Instead, Relax bolts on its Jackpot Stars side bet - a separate button at the bottom-left, optional, with its own progressive ladder of six tiers. Collect three Jackpot Stars symbols and you're entered into the draw, with a top tier worth 12,500x. Run it without the side bet and the ceiling drops to a 5,000x single-spin cap, with the headline 10,409.4x figure coming from a sustained free-spin run. Hit frequency sits under 19%, which is the trade-off any 10/10 volatility build asks for.

This is a 2020 release and it shows in the engine - older HTML control bar, no fancy reel animations, a START screen that introduces the bonus symbol upgrade and the 6-reel free spins before you even hit a wager. A straight homage to Book of Ra with a Relax-flavoured jackpot tacked on top, and that's the whole shape of it.