Formula: perks and buildings
Missile system - the difference in Missile system building levels of attacking and defending regions. Differs from -300 to 0, meaning if the Missile system level of the defending region is more than 300 higher than that of attacking region, the difference value will still stay -300. Only counts in Ground and Troopers wars.
Sea port - same as Missile system, but counts in Sea wars only.
Strength, Knowledge, Endurance - player perks.
Nation bonus - equals 1 when fighting for the regions of your original nation.
Level - player level.
Troops α-damage - sum of α-damage of troops, sent by the player.
Besides that, there will be a penalty, in case you send troops in war for the region which is too far away from your current region.
There is also a random influence on your damage: final result may vary by 1/8 part (±12.5%).