Double Knockback

[Gary]

If an attack with Double Knockback goes through a barrier, is the body doubled for knockback purposes before or after applying the def of the barrier?

For example, a 10D6 EB with double knockback vs a 8 ED force wall and rolls 10 body. Would the base knockback be (10*2-8) = 12", or (10-8)*2 = 4" of knockback?

I would assume that if the attack didn't knock down the barrier at all, that no knockback would be done.

[Steve Long]

The question here really is, I think: “If an attack that could cause Knockback must first penetrate a barrier (such as a Force Wall), is the Knockback calculated from the total BODY damage of the attack, or the BODY damage that gets through the barrier?”

The answer is “the BODY damage that gets through the barrier.” If none gets through, there’s no KB. If some gets through, the amount that gets through would be doubled for Double Knockback purposes.