Better armor can reduce damage taken, but it doesn't have to. In this article I will discuss why the current effective armor formula from the wiki is incomplete.
To test this we use 2 different armor sets that lead to the same health loss per shot.
With 76 armor we lose 3.3 health per hit.
With 81 armor we still lose 3.3 health per hit.
After 10 hits we lose 33 health with both armor sets.
We can conclude that the game does not use a higher precision than what is displayed, hence we should indeed care about the displayed health reduction.
The wiki lists the following formula for the effective armor:
Effective = Total / (Total + 40)
So if we have 82 armor then Effective = 82/(82 + 40) = 82/122 = 0.672
Instead of 10 health we lose 10 * (1 - 82/122) = 3.278 which round to 3.3, exactly what we saw in
Now what about 76 armor:
Effective = 76/(76 + 40) = 76/116 = 0.655
Health loss = 10 * (1 - 76/116) = 3.448 rounding to 3.4
In our test earlier we saw a health loss of 3.3 with 76 armor.
The displayed health does not match the in the wiki described formula for every total armor value. I recommend testing experimentally where the closest armor thresholds for you are in order to not waste money on more expensive armor and without benefit.
If you want to help testing different rounding methods yourself, here are some more data points:
Armor -> Predicted health loss -> actual health loss
46 -> 4.651 -> 4.6
47 -> 4.597 -> 4.6
49 -> 4.494 -> 4.5
50 -> 4.444 -> 4.3
51 -> 4.396 -> 4.3
53 -> 4.301 -> 4.3
55 -> 4.211 -> 4.2
57 -> 4.124 -> 4.1