I'm wondering if this is a bug. I see no reason why these duergars should be able to see duo.

<447hp 675m 498mv 13993tnl> n
A Dark Junction in the Mines


A dark-skinned dwarf stalks the dark tunnel.
You step back into three dimensions.
A duergar scout steps out of the shadows.
A duergar scout's backstab === OBLITERATES === you!
That really did HURT!
A duergar scout is in perfect health.

<265hp 755m 504mv 13993tnl>
A duergar raider's slice MASSACRES you!
A duergar raider's crush MASSACRES you!
A duergar scout is in perfect health.

<126hp 755m 504mv 13993tnl> fle

A duergar scout parries your stab.
A duergar raider's slice DISMEMBERS you!
You sure are BLEEDING!
You dodge a duergar raider's crush.
A duergar raider's slice DISMEMBERS you!
You sure are BLEEDING!
A duergar scout's crush misses you.
A duergar scout's pierce DISMEMBERS you!
You have been KILLED!!