Twin Thunders and Flurry of Blows?

[Booksy]

The feat Twin Thunders talks about applying your off hand damage dice a second time after a successful hit with your main hand.

Flurry of Blows is a pre-req, and it specifically works with blunt weapons.

How does a monk benefit from this feat, since he has neither MH or OH attacks while using FoB?

[Mojorat]

Well, If your not playing PFS just house rule it and move on. ITs not hard to denote which attacks are 'offhand'

lvl 8 Monk flurries for 6 6 1 1. two of those are offhand attacks exactly as if hed had imp twf. If its for PFs... i havent a clue

[Booksy]

That makes total sense as a houserule.

I guess I was looking for an official ruling, because to me as RAW it looks like it just doesn't apply.

[Kazaan]

You're confusing "layman terms" for "mechanically significant terms". When a Monk "has no off-hand", it means they take no penalty to the strength bonus to damage for making "extra" attacks with unarmed strikes. In other words, both their "main-hand" and "off-hand" deal damage as main-hand attacks. Note that, outside of Flurry, this only applies to Monks making Unarmed Strikes. A Monk using two weapons and traditional Two-Weapon Fighting still suffers off-hand penalty to Strength bonus to damage. Inside FoB, all weapons are treated this way so, while you still have off-hand attacks, those attacks are set at 1x Str to damage regardless of which hand they are wielded in or whether they are wielded in two hands or one. So, you merely need to establish an attack as either "main-hand" or "off-hand", making sure to keep proper context in regards to BAB ordering of the main-hand attacks and "first>second>third" ordering of the extra attacks and you consider the extra attacks allowed by the flurry as off-hand attacks for the purpose of the feat. To illustrate:

A Lvl 8 Monk gets 2 iterative attacks and his flurry allows 2 bonus attacks. The general pattern is +6/+6/+1/+1 with the bolded values being main-hand iteratives and the non-bolded ones being the extra attacks from Flurry (which, by flurry rules, can be made with the same weapon as the bolded attacks at your option). They can also be re-ordered so long as the +1 iterative attack doesn't come before the +6 iterative and the +1 extra attack doesn't come before the +6 extra attack, allowing 6 possible combinations. So, if you hit with the +6 attack (main-hand), you fulfill the condition, "If you hit the creature with your main-hand attack", thus your next off-hand attack that hits will gain bonus damage equal to the weapon's damage dice.

Remember that the foremost presumption should be that a rule works. If explicit rules don't give room for it to work, you fall back on implicit reading. In this case, there is an obvious implicit reading that the "extra" attacks in FoB count as your off-hand attacks and, given that the feat offers the choice of either TWF feats or FoB class feature, it's pretty obvious that the intent is for FoB use to qualify for the benefit of the feat. Thus, the implicit reading is acceptable. Only when there is a clear and distinct ambiguity or contradiction in the rules does one presume that there is a problem preventing the particular feature from working properly.

[Booksy]

That makes perfect sense, Kazaan - thanks very much =D

[Krodjin]

Kazaan's logic is sound, but still could be seen as invalid by an obtuse and obstinate GM. There are some of those out there by the way. So Booksy, just be prepared to have some killjoy rain on your parade. It does happen from time to time...

[Kazaan]

Krodjin wrote:

Kazaan's logic is sound, but still could be seen as invalid by an obtuse and obstinate GM. There are some of those out there by the way. So Booksy, just be prepared to have some killjoy rain on your parade. It does happen from time to time...

Obtuse and obstinate GMs are invalid. If one tries to truncheon you with hyper-pedantic readings, ask him to explain why a dead character can't act since the "dead" condition carries no limitation on action.

Moreover...

Sean K. Reynolds wrote:

English is a very fluid language.

In some ways that is helpful because it allows us to express a rule in a natural way in one sentence and in another natural way in another sentence. For example, we can say "if the creature fails its save, it gains the blinded condition," or "this spell blinds the target if it fails its save." Even though "blinds" isn't a condition, you know what that second statement means because you understand that "blindness" and "blind" mean the same thing in the real world and you know that "blindness" and "blind" aren't two different game terms...

Source

Truncheon a pedantic and obtuse GM with this statement, made on behalf of the entire Pathfinder design team that the fluidity of language should not be used to cut out mechanics that, while not explicitly detailed in the rules, are allowed by implication. Now if this were a case of clear-cut mechanical differences such as a temporary bonus to Strength giving a bonus to damage rolls or a bonus to the strength bonus to damage rolls, that is different. That is an actual debate about how the rules are detailed with credible evidence on both sides and mechanical ramifications for both options. But to say that Twin Thunders, which is mechanically relevent to making main-hand and off-hand attacks doesn't work for a Monk because a Monk "has no main-hand or off-hand attack when making a flurry" is pedantic and goes against the implicit allowance, considering the feat itself gives Flurry as a prerequisite option for taking the feat (alongside traditional TWF feats). If a GM tries to pull this on you, he should be laughed out of the game and promptly replaced as he slinks off in shame to the dark corner from whence he came.