For information on how these stats interact, please visit the Unit stats page.
When one unit attacks another one, it deals damage. How much damage is dealt, is dependent of the attacker's 'attack' stat, and the defender's 'defense' stat. If the defending unit isn't killed during the initial attack and is in range, it deals damage back. The amount of damage dealt now depends on the defender's (now attacker's) defense, not attack. If the attacking unit kills the defending unit and its range is equal to one, moves to the defender's tile. If a unit ends its turn on a enemy's city, it will be able to capture this city on its next turn.
Damage Calculator Edit
Unofficial Calculator by FrothFrenzy: http://polytopiacalculator.freevar.com
Attacker's attack is multiplied by their current health divided by their maximum health. (attackForce)
Defender's defense is multiplied by their current health divided by their maximum health. (defenceForce)
Then, attackForce and defenceForce are added together to create totalDamage.
attackForce is divided by totalDamage. The result is multiplied by both the attacker's attack and 4.5.
For information on how unit skills work, visit the Unit skills page.