The Problem with Two Weapon Fighting ?

[Ruvion]

I see it as more of a concentration issue...as you can only focus with one hand more during a combat round (each round, this concentration can be shifted to your previously "off-hand" 'cause of your ambidexterity). Otherwise, if you can put equal strength for both hands you are concentration less on your opponents and may incurr...gasp...attacks of opportunity! 3e way of saying within the short 6 second time frame you can get fully efficient attacks only with your "primary hand" and semi-efficient with your "off-hand". This explains why you can't swing get attacks with your "off-hand" during a standar attack or a charge (you only have a split second time for one attack with one hand or the other).

If you weren't a humanoid on the other hand....you would not be so limited in your concentration...3e reflects this with the Multiattack and Multidexterity feats for non-humanoid monsters.

 

[AuraSeer]

When you attack with a two-handed weapon, you get 1.5x your Str modifier to damage. In order for TWF to be balanced against this, you get 1x the modifier for one weapon, and 0.5x the modifier for the off-hand weapon.