The game's logo is the wild symbol and it can substitute for all the other symbols to help and form wins. There are also two special expanding wild symbols, the Sheriff and the Bandit.
Heart of the Frontier does not have any scatter symbols.
The Sheriff and Bandit symbols will both expand when they land on the reels to fill the entire reel. Then with each subsequent spin they will move one place (the Sheriff to the right and the Bandit to the left) until they drop off the reels.
If both of the special wild symbols land on the reels at the same time then the Showdown Free Spins begin. You are awarded five free spins with the expanded wilds locked in place. If any more special wilds land then they will also lock in place for the rest of the spins.
When the spins are over the shootout begins. Any sheriffs and bandits on the reels will start firing at each other until just one remains. That symbol will stay on the reels when you return to the base game.
Heart of the Frontier offers a top payout of 500x for landing five wilds along a payline. The cowgirl can payout up to 100x, the Native American can payout up to 80x, the prostitute can payout up to 60x, the sheriff's badge can payout up to 50x and the horseshoe can payout up to 40x.