The Periapt of Wound Closure's description says
While you wear this pendant, you stabilize whenever you are dying at the start of your turn. In addition, whenever you roll a Hit Die to regain hit points, double the number of hit points it restores.
Emphasis mine.
What happens to a PC wearing Periapt of Wound Closure while suffocating? I'd like to transport myself using a Homunculus and a Bag of Holding, but I worry about suffocating during the journey.
If I put on a Periapt of Wound Closure and enter a Bag of Holding, will I suffocate to death while inside of the bag or will the Periapt keep me alive?
Best Answer
You would suffocate to death unless it is a short trip.
Bag of Holding:
Suffocating (emphasis mine):
Thus, the Periapt of Wound Closure can not stabilize you. You'd have to start making Death Saves after you drop to 0 HP. Unfortunately, three successes can't stabilize you either, so you'd be making Death Saves until you died or could breath.
Note: The PHB errata updated the wording of Suffocating to include that you can not be stabilized.