hi Louis!
Damage is equal to the difference between the result of the roll and the level of the target. So, if an opponent is level 13, it’s necessary to roll a 14 to start dealing damage. 12 or less means the attacker suffers damage. A result that matches exactly the level of the opponent (13 in this instance) means no one dealt damage on that round.
Remember that the level of an NPC decreases as they receive damage, making them easier to hit.
For the maximum level, I wouldn’t go over 16, but depends on how powerful the hunters are.
In any case, violence should be the last resort, as combat is pretty deadly! Specially getting that first blow clean.