But the 290 damage was the sum of ten components (81 physical, 2 nature, 8 acid, et cetera), none of which was higher than 201 by itself. Also, the attack, according to the description of Telekinetic Smash and the pattern I see in the numbers, was probably actually two weapon strikes, inflicting 6 and 4 of those 10 components respectively; and it looks like neither of the two strikes hurt for more than 201.
So I'm guessing the 50% cap applied to each of the two strikes, not to the entire attack (because that would have clamped the 290 down to 201) and not to each of the ten components of the attack (because that would be strange). Am I right?
If so, I guess I need to be more careful around melee fighters, because they do tend to have various ways of dividing single ability uses into multiple weapon strikes.
