Timber Stacks™ by Pragmatic Play is a 5×5 video slot set in a wilderness theme, with symbols including fish, owls, bears, wolves and standard card ranks. Wins are formed from matching symbols on adjacent reels from left to right. A mountain Wild can appear on reels 2, 3 and 4, where it substitutes for all regular symbols except the Scatter.
The game uses a tumble mechanic, so winning symbols are removed and replaced by new ones within the same spin. If the sequence continues without another win, the grid can expand to 10×5, creating up to 100,000 ways to win before returning to the original layout. Players looking for the Timber Stacks demo version can play for free and use it to practice before playing for real money.
Four or more Scatters trigger the free spins bonus round, which starts with at least eight free games. The increasing grid feature can also operate during the bonus round, and in some jurisdictions the free spins feature can be bought for 120× the bet, with the next spin set to trigger at least four Scatters.