Treatmonk just ran a simulation with TWO completely non-optimized ordinary human fighters level 20 and no magic items. They killed Vecna before Vecna got a single turn.
Well, I would hardly call those builds "non-optimized" but it does show one of Vecna's greatest weakness: the lack of the shield spell. That alone would have kept him alive past their attacks.
His numbers are off, as well. He adds the arcane shot arrow damage twice, when it is just once
per turn (action surge gives you another action, not another turn). The arcane shot also has to be declared when the shot is
fired, not when it
hits. So, if the fighter imbues the bursting arrow and the arrow misses, the bonus damage is lost. He also assumes lucky will add 33 damage for three misses, but that is only if you miss three times. If you miss less than 3 times, it counts as less.
FWIW, I got damage at about 129 DPR per fighter, close enough to finish Vecna if doubled. If the fighters get lucky really at all, expected damage should be enough to finish him off.
Anyway, add in the
shield spell, and how would the fighters have faired after that? Not as well, DPR drops to under 80... so Vecna will easily survive to his turn, then dominate one, heal himself, and likely win the fight. All because of the shield spell.
FWIW, I could make a single level 20 PC Wizard who would crush those two fighter like bugs. IMO, that makes Vecna even sadder.
