Hi, 

Does the swarmkeeper ability gathered swarm  double its damage dice on a critical hit?

The wording of the rules suggest that it's the swarm that does the damage and that the damage is not part of the actual attack, so maybe it shouldn't be doubled? But I find the wording a bit vague so I'm not sure how it is meant to work. 

Thanks

Hmm. It does seem to be worded in a way where it doesn't benefit from crits. Should be balanced even if it does though if the DM allows it.

Agreed. The swarm is not making an attack roll, so it can not crit. 

It is really unclear.  If its not part of the same attack then DR and extra die from crits are weaker. Flip side if its a 2nd source of damage that means one more con check to maintain a spell and a failed death save.  

“The swarm” isn’t a separate creature, or even an independent construct of any sort like a Spiritual Weapon, capable making its own attacks in a way distinct from you. Its just an effect your class adds to attacks and other types of actions, and it’s always in your space and essentially is indistinguishable from you. 

It’s you, it’s your damage, it doubles on your crit.

It says "immediately after".  You attack, you roll to hit, you get a critical, and your weapon damage is increased.  Right after that, the swarm hits.  It doesn't roll to hit, so it cannot crit.

From the "Critical Hits and the Swarmkeeper's Gathered Swarm" thread in this forum rather a while ago.

Hmm, I find that more persuasive than the earlier argument that it’s somehow a separate actor from you. Okay, I’ll agree, it’s a second damage effect after the crit resolves, not part of it.