Sonofapreacherman said:
You haven't done the math. The penalties for two-weapon fighting are -6 and -10. By simply taking the Two-Weapon fighting feat, those penalties fall to -4 and -4. That's +8 worth of attack bonuses.
Sort of.
The thing is, the basic penalties for two-weapon fighting could as easily be written as "-200/-600." Frankly, you'd have to be totally out of your mind to take a -6/-10 to hit.
Suppose that I make a feat as follows:
Negative Energy Attack
Prerequisites: 1d6 sneak attack, 1 Cleric level, evil alignment
Benefits: When making a sneak attack, you can choose for your sneak attack damage to be negative energy damage instead of physical damage. If you do so, you do only 1 point of damage for each 1d6 that you'd ordinarily roll.
Now, I think we could all agree that that feat is not overpowered (it may be inappropriate for a variety of other reasons, because I made it up on the spot, but it's not overpowered, right?)
Now, what if I make a house-rule in my game that says, "Any evil Cleric with sneak-attack damage can do 1 point of negative energy damage for every 1d6 sneak attack damage that they'd normally do, but if they do so, they take a -20 to hit."
After I've made that house-rule, my
Negative Energy Attack feat could be described as, "Giving a +20 to hit." Does that suddenly make the feat, with the exact same effect, overpowered? No, of course not. It's still a rather weak feat -- the creation of an entirely seperate (punitively difficult-to-use) rule doesn't affect that.
Would the value of the Ambi/TWF feats suddenly go up if the penalty for TWF was increased to -20/-18? No, your character with the feats would be exactly the same. He hasn't become more powerful, but, by your description of the feat, it would have gone from giving a +8 to giving a +18! And yet... The character isn't any better.
That's why people don't worry about the "+8." It's not really a "+8." It's a feat which makes a given manuever possible, when it wasn't possible before -- like Spring Attack or something.