Timber Stacks

Pragmatic Play sets Timber Stacks in an alpine meadow: daisies, tall grass, butterflies and rabbits in the foreground, with big trees and snow-capped peaks behind the reels. The name fits the mechanics, because winning symbols vanish and the ones above drop down like timber coming down in a forest, and the grid itself can grow taller as the tumbles continue.

The base grid is five reels by five rows and pays on a ways system, with matching symbols needed on adjacent reels starting from the left. That gives 3,125 ways on the starting layout. After a win, the paying symbols are removed and new ones fall in, and the chain runs until nothing pays, at which point the whole sequence is credited together. Ten regular symbols are in play: card ranks from 10 to A make up the low end, while a fish, cougar, owl, bear and wolf are the animal premiums. Five of a kind pays 0.8x to 1x the bet for the card ranks and 1.5x to 10x for the animals. The wild lands on reels 2, 3 and 4 only and replaces every symbol except the scatter.

The headline feature is Increasing Grid Size. Once a spin or tumble sequence has no more wins, there is a chance a new empty row is added at the bottom and one reel is picked to collapse into it. Reels 1 and 2 shift their symbols to the right, reels 4 and 5 shift them to the left, and reel 3 goes either way at random. New symbols then fill the gaps from above. The grid can reach 10 rows by 5 reels, where 100,000 ways are live, and it returns to the 5x5 size once the tumbles end.

Landing 4 or 5 scatters starts the free spins round with 8 or 10 spins, and the growing grid works there exactly as it does in the base game. Players who prefer to skip the wait can buy the round for 120x the bet, with 4 or 5 scatters placed at random. An optional ante bet raises the stake by 25% and doubles the chance of triggering the free spins.

The published RTP is 96.05%, with 95.06% and 94.05% as lower configurations. Volatility is rated 5 out of 5, the maximum win is 10,000x the stake, and hit frequency is about 1 in 4 spins. Stakes run from 0.20 to 240 per spin. The ante bet, the buy option and standard play all share the same default RTP.