Solution to Armor and Magic Resist Issues
The Issues I deem relevant here:
-Unless you have a lot of it mid to late game, its mostly useless; making it a counterproductive stat for mages and ADCs.
-When 
or 
gets built, that hard-earned gold you spent on tanks items has just gone down the tubes.
-Serious lack of clarity of "how much is a lot?".
-Early game its effect helps but loses most of it's value quickly as the game progresses.
**What I propose is simple: Armor now blocks exactly 1 point of bonus Physical Damage and Magic resist blocks 2 points of bonus Magic Damage.** When calculating reduction of DoT-based effects, the reduction is determined based on the total damage to be dealt. It applies to bonus damage only because that is the amount that scales the hardest, also in this way damage dealt by supports and tanks never becomes non-existent.
_As a side-effect of the this change, the average amount of late game armor and magic resist would be tuned to be anywhere between 200 to 300. _
What this change would do is make every drop of Armor and Magic Resist count, also things like  would only reduce a flat amount and not gimp you below a certain threshold of %-damage reduction, instead 35% penetration vs. 100 Magic Resist would simply means you do 70 more damage (remember magic resist counts for 2) to the target, they still absorb 130 magic damage. In this way tanks would still be tough targets to take down, and even small amounts of defensive stats can still count for a lot of damage reduction for mages, supports, and even ADCs.
