Played on an 8x8 cluster payouts grid, Relax Gaming's Santa's Stack Dream Drop is a risky Christmas slot. A sticky mystery cluster that eventually reveals the same symbol is produced by the Secret Santa Respins round. The maximum prize outside of the progressive jackpots is 20,000 times your bet, and you gain increasingly more guaranteed wilds with each bonus round spin.
For the premium symbols, 5-oak clusters pay between 0.5 and 1 x your stake, and you must have between 5 and 60 matching symbols in a cluster anywhere on the grid to win. You can get an idea of the range from the fact that they pay between 2,000 and 10,000 times your stake for clusters of 60 or more. Wilds can occur anywhere, and they substitute for pay symbols to help players complete winning combinations.
When a wild symbol contributes to a win, you can activate the Secret Santa Re-Spin feature, which changes the winning symbols into Mystery Symbols. With the respin, the mystery symbols stick around, and winning clusters nearby also become sticky mystery symbols.
An area that cannot produce a win will become surrounded by mystery symbols, turning that area into mystery symbols as well. When no further surprise transformations take place and they all display a randomly selected matching pay sign, the mystery reveal occurs.
When you collect at least three scatters in the same respins sequence, you enter the Bonus Round, which awards 5 free spins plus an additional spin for each additional scatter that triggers it above the minimum. Per free spin, wilds are a given, and the mystery respin feature can also activate during the bonus round.
Randomly, the Dream Drop Bonus will activate, and a new screen will appear with 15 Christmas presents. You keep picking Christmas presents until you have three of the same jackpot kind revealed; at that point, you win the jackpot. The Quick, Midi, Maxi, Major, and Mega jackpots all have starting amounts of 1, 5, 100, 25,000, and 500,000, respectively.