Ginger wrote:
My bad - MV is correct.
But if you get a WE or Titan with an invulnerable save (by adding a commisar to it for example) then the WE allocation mechanics come into play, and you can attempt to save each point of TK damage.

Except (and this was the reason for my initial query), it's not exactly clear.
Invulnerable Saves work against "any form of attack".
Titan Killers cause the target to "suffer damage equal to the roll".
By my reading of Firepower (section 1.1.3), an "attack" is the singular initial roll (the MW2+ bit).
Section 3.2.5 then says "If such a weapon hits a war engine then the war engine suffers damage equal to the roll of the appropriate sort of dice.", which to me, is interpretable that if the Invulnerable Save works against the attack, then without clarification, the timing of getting to make the InvSave vs getting to roll the multiple damage, is unclear.
Don't get me wrong, I'm not advocating either side here. I'm happy to play it either way. But without clarification, it's possible to interpret it both ways. Rules consistency is important.
Morgan Vening