Originally posted by jemYZX:

No it's not HP it's "Stamina". Less Stamina the more of the shield damage will increase which will break the guard of that shield. Though I use regular shields and not tower shields. It should be Stamina depends on how much you have before the shield is broke of guarding.

HP has nothing to do with that and only helps the player's characters get far in doses of unguard damage by later enemies depends on what food the player uses.

I mean, if you have no stamina left you can't block/parry, obviously. It's already been like that even before H&H so I thought that was kind of a no-brainer.

Max HP does play a part in blocking/parrying now, after H&H. I suggest you first read the reddit post that I linked -- there's literally a formula there to calculate the minimum HP you need against a mob for your block/parry to be successful. If you don't have enough max HP, your block/parry will fail and you'll get staggered + the attack will go through.