Clovenhoof
Mongoose
So in this example where PA is pretty much mandatory, you would just make it a feature of your game that all character get the power attack feat for free.
You're right, I also thought of that, and it probably would be the right thing to do. I'm considering it, but I'm not sure I want everyone PAing all the time. I have a feeling that with a general damage boosting ability, all other combat-oriented feats become altogether unnecessary.
Another option that just occured to me would be to limit Power Attack to x1 damage for OHW and THW and none for LW, but implement a new extra feat that allows to add double damage when THFing. That way, THFers do kick the most ass, but at least they have to pay an extra feat for it.
By the RAW it's on the contrary so that other styles like TWF have to buy feat after feat just to get _near_ the effectiveness of a THFer with PA alone.
Here's an example how those extra feats might look like.
> Power Attack: 1x damage bonus for OHW and THW, none for LW
|-> Light Power Attack: 1x damage bonus for Light Weapons
|-> Heavy Power Attack: 2x damage bonus for One Handed Weapons
|--> Two-Handed Power Attack: 2x damage bonus for Two Handed Weapons
[Cleave and Great Cleave as usual]
So in this case, you don't get anything for free, but have to work your way to the top by "unlocking" heavier weapons. HPA would be a prereq for THPA because THPA has a higher damage output and thus should cost more. And, since the whole chain now costs one or two feats more, other non-PA fighting styles (like Improved Crit) might actually be worth the bother.
Did anyone even glance at that thread I posted on the Riddle of Steal?
As a matter of fact, I did read that thread, but I heartily disagree with that concept. I'm not that well versed in gaming theory, but in plain English, it's boring if everything does the same and in exactly the same way. I don't want to carry that discussion over here, though.
It's okay, even desirable, if the different weapons and fighting styles net the same amount of kills over time, but they should do so in different ways.
A very simple example is comparing broadsword and battle axe. Both have d10 damage (let's omit AP here), but one has 19-20/x2 crit and the other is plain x3. If you do the math, both weapons will do exactly the same amount of average damage, but they do so in different ways. A very strong character may get more kills out of the broadsword, while a more average fighter can pass the MDT better with the battleaxe.
On the same note, you might be able to equalize kills by means of a feat that increases your critical multiplier, and is compatible with Improved/Greater Crit but incompatible with PA. But it would require some math to verify that a Power Critter scores as many kills as a Power Attacker. Anyway.
The ideal system of balance would be a weapon triangle, in the fashion of the good old stone-scissors-paper. In this case, it might look like:
THF beats TWF
TWF beats S&B
S&B beats THF
It doesn't matter for the sake of this discussion if the triangle should look like this. D20 doesn't compare weapons or fighting styles in this way. You just get a handful of situations where one style is superior to the others. Confined quarters, THWs get a penalty. You get Sneak Attack, TWF rules. It doesn't really work for S&B and much less for OHF, alas.