%damage reduction

[arual]

What is the formula for the amount of damage reduction you get from armor? From just cursory looks I already gather that normal Armor and Magic Armor use the same formula and the return on armor diminishes as it gets higher (as usual in such games).

[Alienbrain]

Dmg reduction = (Armor * 0.06) / (1+ Armor * 0.06)

[Drasha]

Armor does not diminishes as you get more every point is a little bit better then the last.

[n00binator1]

Each point of armor adds 6% EHP, so it's not diminishing.

For example:
You have 1000 hp and 1 armor, you will die after taking 1060 damage(of the same type the armor is)
You have 1000 hp and 2 armor, you will die after taking 1120 damage
You have 1000 hp and 3 armor, you will die after taking 1180 damage
e.t.c.

[Alienbrain]

Armor DOES work diminishing... because every Armor u get reduces less dmg then the previous armor u got.

Just look: http://honwiki.net/wiki/Armor

[n00binator1]

It is certainly not diminishing.

If you have 1000 hp and buy the +250 hp booster you'll get a 25% increase in hp.
If you add another, it will increase your hp to 1500, up from 1250, a 20% increase.
So...
a) Everything is diminishing and the word isn't an actual term and doesn't actually mean anything at all, since it can apply to everything(like health which always adds the same amount).
b) Both of these(armor and hp) are not diminishing.

[ComMcNeil]

armor itself has diminishing returns, effective HP has not

simple as that

[Glorify1]

Damage Reduction = ( 0.06 * ) / (1 + 0.06 * )

Every point of armor, regardless of how much armor you have, provides 6% effective hitpoints(EHP). Armor has no diminishing returns, rather the % reduction does reduce diminishingly. However, this does not make armor diminishing, because as you get higher % the less % you need to reduce the same amount. For example:
0% reduction would require 50% to half the damage
50% reduction would require 25% to half the damage
98% reduction would require 1% to half the damage

[Eserem]

Just to clarify:

One armor point increases your EHP by 6% of your total hp.

[Glorify1]

If you have 1000 hitpoints, 1 point of armor will provide you with 60 EHP.

[Drasha]

Armor DOES work diminishing... because every Armor u get reduces less dmg then the previous armor u got.

Just look: http://honwiki.net/wiki/Armor

holy crap some one updated that page alot from when i first made it with just the formula.

[n00binator1]

armor itself has diminishing returns, effective HP has not

simple as that

They are the same thing, but using 2 different... "scales"
You can't really judge about diminishing returns on a scale that has a clear upper limit, like 100%, because everything in that scale would be "diminishing", because it can't possibly go over 100% and thus at some point it will become diminishing, even if it just adds up the values. For example: having 5 items that each grant 30% damage reduction will result in 30% + 30% + 30% + 10% + 0%, a "diminishing" return after the third one, while the effective return is exponential and becomes infinite after the 4th item(and since there's nothing larger than infinity further items will be useless).

[ElementUser]

If you want some more in-depth stuff, read this: http://forums.dota-allstars.com/index.php?showtopic=67285

But yes, EHP stacks linearly and increases by 6% per point of armor

[Glorify1]

Armor does not stack diminishingly. Just because you're receiving less % reduction does NOT mean you're getting less protection with each point. If honwiki told you otherwise, it's wrong and needs to be fixed.

[arual]

Dmg reduction = (Armor * 0.06) / (1+ Armor * 0.06)

Thank you, that is exactly what I wanted.


As to whether or not the return on Armor diminishes per point depends on how you view your survivability - ie. whether you compare the increased survivability from more Armor to your survivability with no Armor or from your survivability with your current Armor. This is where defining EHP comes in useful.