bonus damage protection and armor upgrades

Malus

Spearman
Dec 27, 2018
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what is the exact formula on how much armor the unit gets from armor upgrades?

it looks like units with low armor get the % mentioned in effective HP, aka if spearman has 0 armor, he receives 0,13 armor from +20% upgrade which makes the effective hp roughly 120%. but for heavily armored units, like war wagon, which starts with 0,8 armor, after upgrade it has 0,88 armor, which is like extra 66% effective HP
 
unit gets the same armor (multiplicative) as is stated in the upgrade but the higher the armor it had before the upgrade the more effective the increase is.
e.g: a unit with 0.8 armor was taking 20% of the enemy damage but a unit with 0.88 is now taking just 12%. if you work it out (8/20 x 100 = 40) that means the unit is now taking 40% less damage from the enemy than it was before the upgrade.
 
war wagons dont start at 0.8 but 0.85, that s what might be confusing you
otherwise, yes, you got it correct, the armor you see in upgrades mean effective hp against the specific dmg type. There is only one exception though and that s Vemundr's upgrade (city defense hero) which doubles his base dmg reduction.

I made a video explaining it: