Effective immediantly, the following shall be in effect when facing off against the varying levels of characters.
Player vs Player: Standard rules with Death of a character needing permission by both.
Player vs mooks: Standard fodder. You can give permission for character death if you like, but generally such isn't required. Characters who fall in the mook catagory would be Undead minions, etc.
Player vs mini-boss: If you engage in battle with one of these, its automatically given that your giving permission for your characters knock-out/near death. True death requires permission, but insofar as limbs lost, or the like? Granted. Prepare for pain if you do so. The Black Hand qualifies for example here.
Player vs Boss: To fight one of these in battle is to automatically give permission for your character to die. Characters like Fafnir fall under these quotas.