So from reading around (specifically, http://www.reignofgaming.net/blogs/a...lse-rp-contest) It seems that you do not get diminishing returns on each point of armor/magic resist if you measure returns based on your Effective HP (the amount of theoretical magic or physical damage it takes to kill you, after factoring in resistances.)

Its not a new article, but I felt like promoting a cool number cruncher, and maybe giving a bit of random advice on a very confusing (for many) topic.

A relevant and rather related article by a writer on A DIFFerent View's panel;
http://www.reignofgaming.net/blogs/a...nces-vs-health

If you don't want to read it yourself, it basically says stacking resists often becomes less efficient due to the abundance of % resist penetration, whereas building health is unaffected by % penetration, but is affected by % based damage... A trade off of sorts....

Anyways by looking at both articles you can formulate you're own "most efficient" build for the specific situation.

Keep in mind that the 'diminishing returns' theory is a bit misnamed. Enemies start with 10% penetration and a certain amount of flat penetration. All we care about for diminishing returns is the percentage-based one.

They will then get possible 40% more from Last Whisper or Void Staff, for a total of 46%.

This 46% pen is applied to ALL your armor you already have, as well as any you may yet get. There is no 'diminishing returns' in that your 200th point of armor is any worse than your 100th point. Its all being reduced by 46%.
I think what they are trying to say is that your armor was really useful BEFORE they got that 40% Apen, but now that they DO have it, all your armor is less valuable. So you don't necessarily want to keep investing in armor.
So its kind of an 'effective diminishing returns' theory. I guess.


If we take an example... say you have 3000 health and 200 armor. They have 50% armor pen to make it easy.

Your EHP = 3000 x 1 over (1 minus armor/armor+100) = 3k x 1/ (1-100/200) = 3k x 2 = 6k health.

Health costs 2.5 gold per point. Armor costs 15 per point. Lets compare 20 pts of armor to 120 health (both costing 300g)

EHP with health = 3120x2 = 6140.

EHP with armor = 3000x 1/(1-110/210) (remember, half that 20 armor is penetrated)
EHP = 3000 x 2.1 = 6300.


As you can see, vs a single source of damage, armor still gives over DOUBLE that of health alone.

Same example, except assume 3k health, 300 armor(!). 50% penetration.

EHP base = 7500

EHP health = 7800
EHP armor = 2.6x3000 = 7800.

In this case it breaks even. But if you boosted health to 4k, you'd see that armor would once again be more cost-effective.

Basically it is still more about getting the right health/armor balance, much moreso than any so called diminishing returns.

Clear as mud? :-)

I tend to aim for 3k hp with 230 armor and MR

Easy Mathematics.

For every 1 Point of Armor or MRes, it increases your Effective HP by 1% it's base.

If you have 4000 HP, and 100 Armor, you are increasing your EHP by 100%. 4k + 4k = 8k ehp

If you have 200 Armor, you now have 12k and so forth.