have an NPC in each capitol where guilds or players can declare themselves "fair fighter".
Once that's done, they get the hellaxa head animation on.
Now if they kill an ennemy with the Hellaxa animation, they get 150% of the RPs of the kill.
If they kill anything else, they get only 50% of the RPs.
It will not prevent all adds but it will at least give a visual clue to everyone passing by an 8v8 fight and they will know you may break your fight to kill the adds.
Once that's done, they get the hellaxa head animation on.
Now if they kill an ennemy with the Hellaxa animation, they get 150% of the RPs of the kill.
If they kill anything else, they get only 50% of the RPs.
It will not prevent all adds but it will at least give a visual clue to everyone passing by an 8v8 fight and they will know you may break your fight to kill the adds.