D&D 5E "Unstoppable" new reaction introduced in Descent?

[BMaC]

The Death's Head of Bhaal has the following reaction:
Unstoppable (3/Day): the death's head reduces the damage it takes from an attack to 0.

Has this ever been in a stat block before? It is nasty--almost resulted in TPK last night. Depending on the circumstance, more powerful than legendary resistance. It made for a great, challenging encounter.

 

[Morrus]

Is it that powerful? It means three times somebody will effectively miss when they would have hit, but PCs miss all the time. An extra three misses in an encounter is notable, but not that much.

 

[Bitbrain]

The nilbog of Volo’s Guide.

As a reaction, it can gain health from one attack instead of taking damage.
Once it uses it though, it’s pretty much screwed, as everyone can then gang up on it and beat it to death.

 

[Nagol]

Is it that powerful? It means three times somebody will effectively miss when they would have hit, but PCs miss all the time. An extra three misses in an encounter is notable, but not that much.

Sure PCs miss. But this kicks in when everything goes right and they hit. So if the PCs burn a bunch of resources hitting and then making sure the hit counts (like a paladin burning his highest spell slot on a smite after hitting) then all those resources and positionings are gone.

 

[Quartz]

How is this different from using a Legendary Action to succeed in a saving throw?

 

[BMaC]

Legendary save does not negate a crit or loads of smite damage. This does. However, this does not negate a failed Hold Person like a legendary save would.

 

[MarkB]

Sure PCs miss. But this kicks in when everything goes right and they hit. So if the PCs burn a bunch of resources hitting and then making sure the hit counts (like a paladin burning his highest spell slot on a smite after hitting) then all those resources and positionings are gone.

Yep, that sucks - but it's a learning experience, just like legendary actions and legendary resistance. Once the party knows it can do it, they can start to work around it - either trying to make it expend its uses against less-costly attacks, or goading it into expending its reaction on some other action before they use their next combo.

 

[Paul Farquhar]

It only gets one reaction. So no, not all that powerful. And it could easily blow it before the big hitting attack came in, or end up not using it because the big hit attack it was saving it for missed anyway.

I can't even see it living long enough to use it three times.

 

[cmad1977]

Pretty sweet! Might use on my own creature later. IDK.

 

[darjr]

It can change an encounter around that’s for sure. The key is the DM can choose to use it at the worst possible moment for the PCs. And if the players don’t know about it it’s a huge surprise.