Quote Originally Posted by GilesTheCleric View Post
A 208: It's "essentia drain" damage. "cone of resonating energy that separates incarnum from living matter and deals damage to creatures (but not objects)." "A successful Fortitude save halves both the damage dealt and the essentia drained.The save DC is Constitution-based."
This it does, but it is an additional effect. Here is the full text.

Breath Weapon (Su): An incarnum dragon’s breath weapon is a cone of resonating energy that separates incarnum from living matter and deals damage to creatures (but not to objects). Every creature within the area must make a Reflex save or be temporarily drained of essentia. This effect reduces the essentia pool of each target by a number of points equal to the dragon’s age category for 1 hour. A successful Fortitude save halves both the damage dealt and the essentia drained. The save DC is Constitution-based.
The bolded part is the essentia drain; this is the bit "that separates incarnum from living matter"; 1/age category. The Breath Weapon in the stat block deals damage of 1d8/age category; what I'm trying to work out is what kind of damage it is. It is untyped, so cannot be resisted by anything short of being ethereal by my reckoning. The example dragon deals 6d8 damage plus 6 essentia.

I have just answered this myself, so okay.