Here is a run down of a situation:
-Death Scourge chases Deimos because both of my companions are down
-I shoot lightning and fire at Death Scourge away from radius of my down companions so I don't kill them
-Meeko comes to my rescue right into my flaming fireball and died
Have to restart
Same situation
-Death scourge chases me away from companions that are down
-I shoot away from my companions
-Stenvar comes to my rescue, I notice he starts fighting scourge
-Scourge is in no way near or close to Stenvar I shoot lightning
-Scourge moves in a radius where lighting hits Stenvar, Stenvar dies
-Reload
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Why for the love of god did Bethseda put Friendly Fire in this game? It's absolutely the single most frustrating thing in the world to deal with.