Actually my understanding is that diminishing returns are tuned to exactly counter this multiplicative effect you're speaking of. (
source)
ElitistJerks wrote:There is some confusion about "diminishing returns" on armor. The DR given by armor follows a diminishing-return curve, so the higher your DR is, the more armor is required to increase it by 1%. However, the value of each extra point of DR increases as your DR increases. For example, consider an attack that does 10,000 physical damage before armor is considered:
* If your armor DR is 50% and you increase it to 51%, the damage done by the attack is reduced from 5,000 to 4,900, a 2% reduction.
* If your armor DR is 60% and you increase it to 61%, the damage done by the attack is reduced from 4,000 to 3,900, a 2.5% reduction.
So, even though your DR% will increase more slowly as you add more and more armor, each extra point of armor is providing roughly the same relative benefit. Hence, increasing your armor is always worthwhile. (For a more detailed explanation with math and such, see Quigon's Protection Warrior Guide.)
Edit: just to make sure we're on the same page here, each
percent of armor will have multiplicative effects, but diminishing returns makes sure that it takes more armor to get to each progressive percent. This is the reason behind why I asked him what percent 800 armor actually did increase his damage reduction, for that to be true he would have to have relatively low armor to begin with in which case 800 armor would make more of a difference.
