Originally Posted by Xypherous
Yes, we'll be doing a pass on all flat / % penetration sources to get them in line with the new formulae.
Currently, max ar pen is too binary in lane, while Last Whisper is *far* too strong because of how it anti-synergizes with flat armor penetration.
The values aren't too far off - in the ballpark of ~ 5% or 5 points for adjustments. Basically, if you only had one source of penetration, you'll see your penetration values go down as a whole because those were overtuned to be independent systems rather than interactive ones.
Man when you guys 1st announced changing order of flat and % armor pen. I hoped that this will make armor pen. runes more viable as well as Brutalizer/Ghostblade and Black Cleaver (old). What you're doing instead is nerfing every source of flat armor pen.
Brutalizer had 50% more armor pen., Ghostblade had 150% more compared to new BC (and probably to new version of itself), and then you're nerfing runes.
Problem with flat armor pen. was that it was becoming weaker late game. So when you announced changes I thought you'll make it viable throughout whole game, but what you'll do with this nerf to its values is that you'll make it non viable investment at all stages of the game if amount will be that small. So % penetration will be even better choice over flat then it already was.