Should kharn or his bezerkers fail a blood frenzy test what do they do to attack each other?

I don't believe they do, I think friendly fire is only for dreads. The zerks just have to move toward the closest enemy unit (whether they can damage it or not) and assault if possible. It will also force disembarkation from any vehicle they are in.

If I remember correctly, I'm not going to bother looking in the book again :lol: