If you are unsure what to aim at, then targeting chest or head are the safest choices. There are a few specific items that do certain things when aimed at certain zones. Hurting the head, legs or arms with enough brute damage can cut them off when using a sharp weapon. Each limb has its own pool of hitpoints but damaging them also counts towards the target's total HP. You can target specific damage zones by using the Numpad Keys. If you whisper you will say your last words and succumb to death. In this state you will be unconscious and slowly die. After losing 150 hp you enter a hardcrit state.All you can do in this state is slowly crawl, and whisper. After losing around 100 hp (depending on mood) you enter softcrit.If you have over 40 total damage of any types you get slowed down until healed.Some good to know basics about the combat system.