When playing fortress 3 fight game, you will have to destroy your opponents fortress in battle before they destroy your fortress
So choose one of the nations then win a catapult battle online for this game.
You have to simply use your finger to choose a bending power in which it is kind of primarily defensive in nature.
Afterward choose a weapon then aim your weapon when your opponent tries to attack your fortress
On the other side just press and hold your finger to power up and down, then release to fire during having a battle with your opponent to defend your own fortress.
Try to launch fireballs and more weapons at the other village.
You can launch those weapons to take down their dojo in that village.
You have to target the Bending Masters Tower in order to impair your opponents bending power.
Note that every fortress projectiles have unique capabilities so try to use them in the right moment when attacking the opponents fortress in this game.
In addition you will have struggle harder to target your opponents armory to reduce their weapon supply.