Talk:Last Whisper/@comment-24055932-20140223140203/@comment-6016076-20140505082827

The relative gain in % damage amplification decreases the larger the armor becomes, but the flat value of the LW increases. Every stat follows the former trend, but not the latter. This gives LW actually an advantage over most other stats against opponents stacking armor.

Also, % penetration is not efficient against targets with low armor when compared to alternative items like Bloodthirster.

Flat Pen simply does not scale at all, so there isn't much detail to provide surrounding it other than its efficiency early game.