I just finished playing the Rebellion quest line, on the Stormcloak side, and the last thing I was asked to do was mop up the Imperials at the various camps.

Well, I've tried this, when I run across them, but the legates seem to be unkillable.

What gives?

Yeah, everyone has this issue. I assume theres an error in the script somewhere that makes them retain their essential status, i guess.