Question about undead and magical weapon qualities

[Doc_Filth]

Hi, I hope this is the right place to ask this:

If an undead creature is attacked with a weapon with a special ability that requires a critical hit to activate it (such as thundering)), can it still be subject to the effects of that ability even though it's not subject to the critical hit itself? I'm erring towards thinking it should; am I wrong?

[sleepyphoenixx]

You are correct. It's explicitly spelled out in the rules for magic weapons (https://www.d20srd.org/srd/magicItems/magicWeapons.htm):

Magic Weapons and Critical Hits

Some weapon qualities and some specific weapons have an extra effect on a critical hit. This special effect functions against creatures not subject to critical hits, such as undead, elementals, and constructs. When fighting against such creatures, roll for critical hits as you would against humanoids or any other creature subject to critical hits. On a successful critical roll, apply the special effect, but do not multiply the weapon’s regular damage.

[Doc_Filth]

I'm glad it's as simple as that. Thanks!

[KillianHawkeye]

However, your specific example of Thundering still won't work because the on-crit deafening effect requires a Fortitude save, which undead are immune to.

[Doc_Filth]

But would they not take the extra sonic damage?

[KillianHawkeye]

But would they not take the extra sonic damage?

Sorry, I misread the ability and thought the damage was always on and the crit effect was just the deafening.

So yes, the sonic damage would happen; undead are only immune to the separate deafening effect.