Gold Hit: Oro Azteca Slot by Playtech

Stone step-pyramids rise out of the jungle behind reels that don't line up evenly, each column a different height, spreading combinations across 4,608 ways. The premium symbols read straight from Mesoamerican iconography: an Aztec king in a feathered headdress, a jaguar, an eagle, a coiled snake and a crocodile. Land three or more matching on consecutive reels from the left and it pays.

The coins run everything else. Cash Prize, Multiplier and Mystery coins lock where they drop and sit for at least three spins, and the counter resets back to three every time another coin lands on that same reel. Keep feeding a column and it never lets go. Fill an entire reel with coins and every prize on it pays out at once. The Multiplier coins are the ones to hope for, since an xN coin multiplies all prizes locked on its reel, in the base game and during free games alike.

Mystery coins hand out one of four fixed jackpots at random: Mega at 500x, Major at 100x, Minor at 50x, Mini at 20x of your total bet. No pick screen, no skill, just a random award when one shows up.

Three, four or five Bonus symbols award 10, 12 or 15 free games, and the locked coins stay put the whole way through. Fill a reel during the bonus and you spin a wheel that multiplies every prize on that reel by up to x10. When the free games run out, everything still on the board gets paid. There's an ante option too, Double Chance of Bonus, which lifts your stake (7.00 on a 5.00 base, say) to double the odds of triggering the round.

If you've spun Tiger Falls or Dragon Bonanza, you already know this machine. Oro Azteca is the Gold Hit coin-lock engine in an Aztec skin, with medium volatility keeping the swings fairly tame. A top payout of 1,000x total bet is ordinary for a hold-and-win, so the draw here is the steady coin-filling grind, not one enormous hit.