Two fortresses are at battle, and it is the player's job to "destroy" his or her opponent's fortress before the player's own fortress is taken down.
All actions are performed through the left mouse click.
- Holding down the mouse click allows for one to choose the strength of the proceeding attack, and depending on where the mouse stands at the time of projectile release, the projectile's landing area will be determined. (additional information below)
Unique effects of any attack come into play depending on what size projectile is chosen. A small projectile has the highest chance of making contact with the target, but it causes less damage; medium-sized projectiles spread out to cover more area; and large projectiles have the least accuracy and deal the most damage.
By holding down the left mouse click after having chosen a projectile, the amount of strength can be chosen. An arrow will appear during this process to give visual representation of how much strength is being applied by the mouse.
Finally, by placing the mouse at any random point on-screen at the time of firing a projectile, the outcome of the shot may differ completely. Angled too highly or lowly, the catapult might shoot a projectile an extreme distance away from its actual desired location. The size of the projectile also affects this outcome.
Firing a projectile through a circular green object will reduce the damage to one's fortress, and the black-and-gold-patterned version makes it so that the projectile shot through it inflicts greater damage upon impact.
Damage occurs when a projectile makes contact with a fortress.
The destruction caused to the opponent's fortress raises one's points on the "damage score". Both the player and the computer opponent have a damage score that goes up each time a projectile makes contact with another fortress.
As more damage is dealt, an untitled gauge will begin to fill with a red color, and a Fire Nation insignia denotes where the gauge is currently stopped. When the gauge is full, the fortress to which the gauge belongs is officially defeated.
Two-player mode is played much the same as the normal (single-player) mode. The only difference is that in two-player mode, the game is done on a turn-by-turn basis not against the computer, but with an in-life playmate.
"Email Battle" was a feature that can be inferred to have been used as a way to play the game across two computers, but it is now obsolete.
Upon clicking the "Email" icon on the title screen, a message that reads "Choose your fortress" will be displayed above Earth Kingdom, Water Tribe, and Fire Nation fortresses. By clicking on either one of them, a prompt to input one's name and email address as well as one's "opponent's" email address appears. Whether or not any of this information is filled in, pressing "Send" does not accomplish whatever is supposed to occur, instead perpetually displaying a "Sending ..." message from then-on. The page must be refreshed to continue playing.
- Once a battle is completed, the game simply focuses the screen onto whichever fortress was destroyed, and no mention is made of how the battle (as well as the game) has ended. The music still plays, but no actions can be performed on the battlefield whatsoever. It is possible to leave the game and return to the title screen by simply clicking "Quit".