Dvati, does one twin casting provoke at the other twin?

[Banaticus]

Re: a Dvati character: http://dndtools.eu/races/dragon-compendium--109/dvati--31/
"When a dvati casts a spell, both members of the pair must focus and concentrate on it. Both twins must simultaneously take the actions required to cast a spell, although only one must supply material components. One twin cannot cast a spell while the other attacks, for example. A lone can cast spells if his twin takes no actions while he casts. Any other sort of action, including a free one, makes it impossible for the casting twin to focus and use his spell. If the dvati tries to use a spell anyway, his casting attempt is ruined and the spell is lost."

Ok, so both must focus and concentrate. Both must simultaneously take the actions required to cast. But a lone can cast if his twin takes no actions while he casts? There seems to be some contradictory information. I interpret it as a clarification of the previous sentence, that one cannot cast while one attacks.

[TuggyNE]

The title question can be answered in the affirmative, since concentrating on something (a skill or spell) provokes.

[Doc_Maynot]

"Both twins must simultaneously take the actions required to cast a spell."
This states that when one twin is casting, both are casting. Thus both twins would provoke.
On top of that, the other twin can take no other action DURING the casting, because as it said both are casting. One casts a quickened spell, the other still can act. One casts a swift action spell, no swift action for the other. One standard action spell, the other gets no standard action. Full round? Only a swift action. Casting time greater than 1 round? No actions until the spell is cast.

[Segev]

I believe the OP is focusing on the second clause, about dvati who are separated by distance having one "do nothing" while the other casts.

I'd argue that no, they don't provoke, because you paid a bloody +1 LA for the ability to have two bodies, and you get so very little benefit out of it as it is. No need to make an already sub-optimal choice for this race (spellcasting) even worse than it would be for a member of a 0 LA race.

[Psyren]

Both twins must concentrate - it's pretty clear to me.

And really it's not that big a deal, just cast defensively.

[Segev]

I'm certainly not going to argue too strenuously. Dvati rules are incompletely and poorly written.

I love the concept. But oh boy, trying to make it work in a game. x_x