I'm wearing advance power mk2 (enclave one).
And i'm in vault 15 and the guards are punching me and inflicting 10 damage atleast everytime.
I thought power armour was supposed to be almost impenetrable and the successor to tanks.

Was it critical hits?

some were some weren't.

... Maybe they shot you in the eyes?
I really don't have any idea, but I never had much issue with the enclave's PA.
Enemies usually just did 0 to 7 in damage, critical hits going as far as maybe 13.
So I dunno, maybe they just got lucky.
Go fight Metzgers Slavers Guild and see what the damage inflicted upon you is.

Lol a vault 15 guard had a 164 crit on me no lie , I was freaking out.

I ended up having to run away with 4hp left.
Ohh where can I find tandi so I can get the ncr to take over vault 15?

What's your PC's Luck stat?

Ideally Tandi is the one who should have sent you there.

The ones punching you may have had power fists.

The melee guards have a very high melee skill; but I just tried a level 1 PC wearing ADVMKII, and they held up for many turns while suffering multiple point blank burst attacks from SMGs and combat shotguns. I did not see any power fists; but several were using Mentats.

Hmm i'll need to check but my luck should be atleast 5.
Yeah I was in vault city trying to find vault 13 but had no info on it so I went to 15 out of curiosity amd it made sense to try there.
Ohh is the gov building in the den?

Usually my pc shrugs off everything, but he was getting 164 dmg crits on him for fun.
I'd try run away but they always got a crazy crit.And one guy 17 dmg with his fists were as (dorin spelling) done about 3hp with a flamethrower.

Its in Shady Sands, shown on the map as NCR. The Den isn't part of the NCR, yet.

https://www.youtube.com/watch?v=m-DXU6tG3WQ&feature=youtube_gdata_player

Here is a gun thug doing 15 damage non crit to me with a smg. Thought it would help.
Sorry for the quality .