This is getting interesting...
Flurry doesn't incur a penalty once you get to a high enough level. It has different damage properties than TWF and is not magical like haste (and does not stack the same as haste). Considering these things, it makes perfect sense to treat flurry as a distict action rather than try and shoe-horn it into existing mechanics.
That's pretty much what I was thinking - flurry is a special action, not TWF. I know the penalties decrease, and that it's not magical, blah blah blah... but my question is: can you combine it with TWF, or are they exclusive? Can you, for example, wield a kama in one hand and a short sword in the other, and get a flurry AND extra attacks with the short sword?
TWF also cannot be performed with only an unarmed attack because TWF explicitly requires two weapons, and all creatures only have a single unarmed strike. You can't TWF with your two fists anymore than you could TWF with a knife that you toss between your two hands.
Agreed.
Well, it think you just explained the reason why gauntlets require proficiency, and why they aren't classified as special monk weapons.
...
Just to clarify, the gauntlet is technically a simple weapon (which monks are not automatically proficient with) and is not a special monk weapon (which is a specific list). So a monk cannot flurry with one, and if they make a normal
attack with one they take a -4 penalty.
That's why they aren't monk weapons and monks can't flurry with them... but why do they require proficiency again? I don't think they do - they're just listed in case someone in armor makes an unarmed attack (i.e., punches someone in the face). It's exactly the same, except you can deal lethal damage.
Don't you need a full round action to get in your 2 weapon fighting extra blows? The monks flurry of blows has already used up all the full round action, so either you use flurry of blows or TWF not both together.
Yes, both are full-round actions, so your answer seems to make sense.
Actually looking into it further a 16th level cleric with two weapon fighting, improved two weapon fighting and greater two weapon fighting would have more attacks than a 16th level monk using flurry of blows which does not seem fair on the monk. So on balance I think it should be allowed.
Yes, but the 16th level monk is dealing 2d8 damage with each attack. This is, perhaps, WHY it scales like it does - so he can keep up with the TWF fighters. Let's compare a rogue (rapier and short sword) with the monk (flurry):
Rogue: 6 attacks (3 main, 3 offhand), avg dmg: 10.5 (main) + 10.5 (offhand) = 22/round. Even if he had a longsword in the main hand, his damage would be 13.5 + 10.5 = 24.
Monk: 5 attacks, avg dmg: 9 each = 45/round.
Monk wins. Fatality.
Flurry is a full attack where all attacks in the full attack action must be Monk weapons. You can add TWF to it, but you must TWF with two weapons. You can't TWF with two Unarmed Strikes, because there is only one Unarmed Strikes so you can't TWF with "two" Unarmed Strikes.
But... as noted above, TWF and flurry are both full-round actions. If you're wielding a non-monkish weapon (say, a short sword) in your offhand,
you can't flurry. You're now using two weapons, and it defaults to the TWF rules.
And the Monk couldn't Flurry in the same round he used the Gauntlet and the Gauntlet would deal size based damage (not Monk Unarmed Damage.)
Hey look, we agree on something.

But... you've just contradicted yourself. Since the gauntlet is not a monkish weapon, he would be fighting with multiple weapons while making attacks with it. Ergo, you can't combine TWF and flurry. Right?