The problem is not that with 13 Cha you only got 3% combat advantage damage but what 1% combat advantage does. I don't think there is a bug with the % CA Cha gives you but we don't know how the game calculates the dmg you do in CA mode. That's why we don't really know if Cha is better than Str. But yeah, with underhanded…
0.84% is the max damage you can get with this feat if you have 24 str (with 18 str at first and +6str at lvl 60) because 14%*0.06=0.84% If you have 10 str it's the same thing as if you have 0 str...no bonus! So if you have 15 Cha it's 5% CA dmg not 15% and 20% of 5% is 1%. For a 24 Cha character, you have with the…
Going to reroll to restart with a 16Dex/16Str/14Cha build instead of 18Dex/15Cha/13Str build and focus Dex/Str with power instead of Dex/Cha. After reading every posts including those in the archives, I think a Dex/Str build should be better for PvE/PvP play (yeah lot of damage and crit!).