Two Weapon Fighting and Insightful Strike

[Garetek]

How does it work? If I am wielding two rapiers? Which are both light finesse weapons?

[Douglas]

You're going to have to be more specific. I know of at least three things in D&D 3.5 that are called "Insightful Strike".

[SilverLeaf167]

First off, even though you can use Weapon Finesse with a rapier, it is still a one-handed weapon and would take larger penalties for TWF. I recommend using a shortsword in your off-hand.

The maneuver states that you make a melee attack. So, you attack with one of your weapons, not both.

EDIT: This assumes that you meant the martial maneuver Insightful Strike from Tome of Battle.

[Garetek]

My apologies. I meant two weapon, improved two weapon, and the swashbuckler insightful strike class feature.

[Keld Denar]

Just like Sneak Attack, you get a Swashbuckler's Insightful Strike on each attack that qualifies, regardless of how many attacks you may make in a round.

As noted, a Rapier is NOT a light weapon. It is one handed with a couple of special caveats.

[FMArthur]

You would need to take Oversized Two Weapon Fighting (CAdv) to TWF with rapiers without the penalties being -4/-4. It's probably better to just use a rapier and some other light weapon, like a kukri, since the difference in damage dice is so small to be spending a feat on.

[Douglas]

As noted, a Rapier is NOT a light weapon. It is one handed with a couple of special caveats.
One of which, as stated in the Swashbuckler class description, is that the class's Insightful Strike ability does work with it, along with any other Finesseable weapon.

If you have BAB +6, Improved Two Weapon Fighting, 3 levels of Swashbuckler, and are wielding two rapiers, your full attack would be +2/+2/-3/-3 plus dexterity and any other bonuses, and each attack would get your intelligence bonus to damage in addition to any other modifiers. If you took Oversized Two Weapon Fighting, it would reduce the penalty by 2 - TWF penalties are not one of the things that rapiers act like light weapons for.

[Garetek]

Got it. It's actually for my pirate character. Wanted to see how much damage I can put out per turn.

Factotum/fighter/rogue/swashbuckler
3/2/3/3
with 2 masterwork rapiers.
Two weapon fighting
Improved two weapon fighting
Weapon finess
Strength 16
Dex 18
Int 20

[ffone]

If you're a rogue-swash you'll likely want the Daring Outlaw feat to stack rogue and swash levels for sneak attack (and swash's grace and dodge).

Although I see you're quad-classes so I dunno how many levels of those particular 2 you plan to take. At your current levels it'd only be one extra die and +1 dodge. But if you take a lot more swash levels, that feat by itself makes more than 3 levels of Swash much better than it was otherwise. If you 'wanted to see how much damage you could output per turn', as you said, and are TWFing, then you probably want a lot of sneak attack dice. And the Craven feat, which basically every sneak attacker takes.

Swash gets Weapon Finesse at L1 so you should have more feats than you listed, esp with the fighter levels.

And as much as I hate to kowtow at the altar of the Spirit Lion Totem Barbarian dip, just like everyone and his brother does, Pounce makes a more drastic damage output difference for TWFers. Or you might prefer a Travel Devotion Cleric dip (getting into flanking position often means moving to a square other than the nearest one). Or if you're rich, a number of belts of battle, quicksilver boots, anklets of translocation, etc.

[Garetek]

I have a few other feats s well but I did not list them because I did not belive that they were pertinent to the questions being asked is all.

They Mainly deal with the ranged side of combat.

[dextercorvia]

I have a few other feats s well but I did not list them because I did not belive that they were pertinent to the questions being asked is all.

They Mainly deal with the ranged side of combat.

I will say that splitting your feats between two feat intensive combat styles is going to make it hard to do either well.

If you have a good Int, and you can fit it, Knowledge Devotion makes a good feat for both ranged and TWF.