I would say that you could throw as many daggers as your iterative attack bonus allows (for one-handed weapons like daggers, javelins and shurikens anyhow). Thus you could only throw two daggers with Rapid Shot. Fighting with two weapons (such as daggers) in melee is not the same as using them as ranged weapons.
Of course, the GM should make the ultimate decision and the players should accept his or her ruling.
by RAW it works. you would get 3 thrown dagger attacks at a -4 penalty.
2 weapon fighting does not explicitly require the weapon to be a melee weapon. it stacks with rapid shot for this particular purpose. just remember that you get half your strength bonus to damage with the 3rd dagger.
your to hit bonus is going to be rather low as 2nd level characters have very little to work with for bonuses.
by raw, (or at least common opinion) it does work. you would get 3 thrown dagger attacks at a -4 penalty.
2 weapon fighting does not explicitly require the weapon to be a melee weapon. it stacks with rapid shot for this particular purpose. just remember that you get half your strength bonus to damage with the 3rd dagger.
I suppose it does not specifically say that you can't (by RAW). I don't think it's a very effective combat strategy however.
TWF specifically works with thrown weapons. As does Rapid Shot. The only question is: "Is there some reason why they shouldn't work together?" This reminds me of the old 3.5 TWF Flurry of Blows discussions. PF fixed that by rewording Flurry of Blows to not allow the two to stack. They did no such thing with Rapid Shot.
Anyway, RAW this works, RAI who knows.
While the strict letter of the RAW allows it, I don't believe it is the intent, for the following reasons.
1. Clearly both feats do the same thing, one for ranged only, and one for (presumably) melee only. I say presumably because that's the gray area. I believe the writers inteded one for range and one for melee.
2. I don't believe it was ever the intent of the writers to give anyone 3 attacks as early as 2nd level.
3. Rapid Shot mentions "fire one additional time". Bows fire arrows. Crossbows fire bolts. Daggers, handaxes, javelins, etc., are not "fired".
4. TWF mentions "fight with a weapon wielded in each of your hands". Wielding is different than throwing. When you wield a dagger you are holding it in your hand to strike with it, quite different than what you do when you throw it.
Yes, I know those are four flimsy rationalizations. And as I've already stated, the RAW supports using both feats simultaneously with thrown weapons.
I just don't think that was the intent.
There's rules for 2wf with Xbows in their weapon descriptions, so that makes me think that 2wf with all ranged is ok as long as you can find one handed weapons to throw. RS, DA, 2wf, i2wf, a master thrower should be able to fill the air with their chosen damaging objects, it's a classic fighting style. There's plenty of drawbacks to balance out its range and extra attacks, not the least of which is the prohibitive cost to getting enough magic weapons.
Fighting With Two Weapons
If you wield a second weapon in your off hand, you can get one extra attack per round with that weapon. You suffer a –6 penalty with your regular attack or attacks with your primary hand and a –10 penalty to the attack with your off hand when you fight this way. You can reduce these penalties in two ways. First, if your off-hand weapon is light, the penalties are reduced by 2 each. An unarmed strike is always considered light. Second, the Two-Weapon Fighting feat lessens the primary hand penalty by 2, and the off-hand penalty by 6.
Table: Two-weapon Fighting Penalties summarizes the interaction of all these factors.
Double Weapons: You can use a double weapon to make an extra attack with the off-hand end of the weapon as if you were fighting with two weapons. The penalties apply as if the off-hand end of the weapon was a light weapon.
Thrown Weapons: The same rules apply when you throw a weapon from each hand. Treat a dart or shuriken as a light weapon when used in this manner, and treat a bolas, javelin, net, or sling as a one-handed weapon.
emphasis mine
TWF clearly works with thrown weapons.
Upon review, Rapid Shot only works with ranged weapons. Daggers, while thrown weapons, are classified as melee weapons not ranged. Darts, Javelins, Bolas, Nets, and Shurikens are both Ranged Weapons and Thrown Weapons and can be used with both.
While Rapid Shot does say "fire" it is an ambiguous term with no in-game definition. Ranged Weapon does have a definition. So does Thrown Weapon and Projectile Weapon. If Rapid meant "Projectile Weapon" it would have said so instead of naming a different category of weapons.
It's worth mentioning that, of these weapons, only darts and shurikens are considered light and can be thrown off-hand without additional penalty.
Agreed on the fact that TWF + thrown weapons are fine.
On light weapons i assume you're referring to this rule:
Thrown Weapons: The same rules apply when you throw a weapon from each hand. Treat a dart or shuriken as a light weapon when used in this manner, and treat a bolas, javelin, net, or sling as a one-handed weapon.
It doesn't even mention daggers or throwing axes or light hammers, let alone starknives.
I reckon they're considered light weapons as well. Thoughts?
Agreed on the fact that TWF + thrown weapons are fine.
On light weapons i assume you're referring to this rule:
Thrown Weapons: The same rules apply when you throw a weapon from each hand. Treat a dart or shuriken as a light weapon when used in this manner, and treat a bolas, javelin, net, or sling as a one-handed weapon.
It doesn't even mention daggers or throwing axes or light hammers, let alone starknives.
I reckon they're considered light weapons as well. Thoughts?
Daggers, throwing axes, and light hammers are all light melee weapons. They keep this quality even if you throw them. The other weapons listed: dart, etc. are ranged weapons which aren't classified as light, one-handed, or two-handed. They're just ranged, so some clarification was needed concerning TWF with these weapons.
Edit: Found this half-hearted (half-right) post by James Jacobs.
Agreed.
