11. Armor vs. Evasion and Butterfly vs. Assault Cuirass

Both armor and evasion increase durability against physical attacks. Which is better?

Each point of armor increases your "effective hit points" by almost exactly 6% of your total hit points. Evasion is also equivalent to having more hit points, when strictly looking at physical attacks.

If you are a hero with 0 armor and you add 6 armor (550 gold chainmail adds 5 armor), this is like having 36% more hitpoints, already more than butterfly's 35% evasion.

So what's the catch? Why do we ever want evasion if armor is so good? It's because although each point of armor is worth 6% of your total hit points, it does not increase EHP by 6%.

If you are going from 6 armor to 12 armor, this is a 36 additional hit points/136 effective hit points = 26.5% increase, significantly less than butterfly's 35% evasion.

Thus agility heroes with high natural armor benefit more from Butterfly's evasion while low-armor strength heroes prefer Assault Cuirass's armor.

However high-armor strength heroes like Dragon Knight may consider a Heaven's Halberd for evasion while also benefiting from the strength bonus!

And then the other teams carry gets a MKB!

Which is a good force because MKB as a damage item is least-optimal when there is no evasion or miss chance, whereas even without the evasion bonus Butterfly on most agility heroes is still the best item.