Originally Posted by ABCoLD
The problem with Dual Wielding vs Dueling is that Dualing more than doubles your damage compared to dueling. The only merit of Dueling is that you give up an entire other attack for a +5 to hit (comparably) and a +3 to damage at high levels. Vs the 10-65 damage, +2 to Charisma and +2 to Defense theoretically that wielding a second saber can give you. (That's the best combo I've found.)
I would say that Dueling isn't useless on its own merit. Rather, the game makes it useless by providing insane upgrade options for weapons and giving most opponents rather poor Defense.
The extra attack wouldn't do you any good if you were unable to hit your opponent with it, while Dueling would give you an easier time to actually land your blows on the opponent, doing damage.
As it is now though the Exile will rarely ever miss an opponent once you gain a few levels (and your party members will pretty much never miss if the main character has decent charisma due to the Attack bonus that grants), thus rendering Dueling less attractive.
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Anyway, as far as I know the bonuses granted by the Dueling feats are hardcoded in the game engine and cannot be tweaked. While you can check for the presence of the feats with a script and apply an extra bonus that way, said bonus would conflict wih those granted by Force Powers and such due to the stacking and max value cap behavior for scripted effects that the game engine enforces.
As for increasing blaster/saber damage this is fairly easy to do, the base damage values for all weapons are set in the baseitems.2da
Though, you'd need to boost the Defense of everyone of significant level or importance to compensate to prevent one-hit kills. I can't remember very many lightsaber duels in the movies where one of the combatants goes down in one swing from their opponent. Neither can I remember any Stormtroopers gunning down Han/Leia/Chewie with their first shots fired on the Death Star or the Cloud City.
Translated to game terms, everyone in the movies have very little VP but significant Defense. Weapons are deadly, but rarely hit their target dead-on.