Fei Long Zai Tian Slot by Playtech

The blue orb with a green dragon coiled inside it is the scatter, and it carries the whole game. It pays from anywhere on the grid instead of along a line, and three or more open the free spins. That's the only way in - no buy button, no ante, no second trigger to keep track of.

The green dragon itself is the wild, and it lands stacked, one long body filling a whole reel top to bottom rather than sitting in a single cell. So a single dragon plugs an entire column and completes a run of paylines in one drop. It also tops the paytable, which means the fattest wild stack and the biggest line hit are the same symbol. It stands in for everything that pays: the phoenix, the money toad, the koi and the rest.

The free spins are where those stacked dragons earn their keep. During the round they pair with multipliers, and full dragon reels stretch a single win to as much as 15x. Get a couple of them landing behind a live payline and the multiplier does the heavy lifting, so the round leans much harder than the base game ever does.

Everything sits on deep-red silk reels inside a carved gold surround topped with a dragon, over a misty lotus pond dotted with pink water lilies and purple mountains fading into cloud. The detail that dates it, and the one worth a second look, is the low end. Instead of the usual 10-through-A royals, the small symbols are the five Chinese elements written in coloured calligraphy: earth, wood, water, metal, fire. Above them come a fiery phoenix, a golden money toad squatting on a heap of coins, and a pair of koi. It's an older in-house Playtech build with no jackpot anywhere, so the pull is the dragon filling reels rather than the maths behind it.