stainer wrote on May 17
th, 2012 at 2:18pm:
I need someone to break everything down without numbers. Should I have PA on if I am playing a barb,ftr, ranger and should I get rid of it on my wf FvS?
Assuming twitching: generally speaking, if your "modified AB" (my term, which i define as AB + 10.5) is significantly greater than mob AC (~1.5x~1.6x or higher), then PA is basically always worth using. If your modified AB is in the same range as AC (less than ~1.4x AC), then PA is basically NEVER worth using.
Pluggin in some real numbers, 1.33x AC is the breakeven for 200 dmg/swing and a PA of 10 (=20 dmg/hit). If you have less than 1.33x in this case, don't use PA. Above 1.33x, you're technically better off using PA, but in this gray area, the difference is very very marginal, that you're probably best off not using PA just to be on the safe side. PA is really only worth using when you can leverage the fact that losing AB doesn't actually decrease your hit chance (~1.6x or higher). It's also worth noting that the more damage you're doing, the less you want to be using power attack.
Basically, I think this is more or less the same as u13. However, it does put much more emphasis on mob AC, since the ratio matters now (as opposed to the difference as it was before). So whether PA is a worthwhile feat really depends on how high they're going to make mob AC. If I had to guess, I'd say that low AB characters will want to strongly reconsider. There are a lot of nice melee feats available that PA isn't a "must have" anymore.