One; it just depends on the strike. The good news is, if the people attacking your character don’t know what they’re doing, the human body can take an absolutely absurd amount of damage.
Without going into a huge article on internal injuries, when you’re dealing with an untrained fighter, like most bullies, the answer is, “quite a bit.”
I’m going to make a quick aside: because of the way they fight most bullies do not (usually) develop into street fighters. They rely on violence, but they’re motivations don’t lead them to want to be better combatants. They don’t look at moves they see elsewhere and keep playing with them until they can do them. In short, when I’m talking about untrained fighters this time; I don’t mean street fighters.
Anyway, there are a couple vulnerable places that can turn lethal quickly: the neck & throat, head, lower back and spine. For your purposes, you’ll want to avoid blows to these.
Blows to the upper torso, stomach, arms, legs, and even (to some extent) the face, aren’t that dangerous, for a couple reasons. Note: this isn’t true with trained fighters, but, we’re dealing with bullies here.
The first is muscles. Tensed muscles are amazing at absorbing blunt impacts. The skin will still bruise, but for the most part, if someone has managed to tense up their muscles properly, simple punches won’t do too much damage.
I’ll probably never type this again on this blog, but: you can probably try this right now. Feel your stomach, poke it a bit. Now, tense up your abdominal muscles and try it again. The same principle applies to someone trying to punch your character.
Even with proper tensing, blows will still cause bruising, and can be painful, but they won’t be life threatening. For reference, the kind of bruising we’re talking about is bleeding that occurs just under the skin.
For the arms and legs the situation is a little different. The legs are basically nothing but dense muscles that are almost always tense. And, for untrained fighters, and even most trained ones, kicking or punching below the waist are awkward strikes.
For trained combatants, strikes to the arm always involve locking it in place first. If a combatant fails to do that, or doesn’t understand that it’s necessary, the arm will be pushed away before being injured. What this means is, most of the force generated hitting someone in the arm is lost to simple physics.
The face is a complex situation. A lot of untrained fighters will try to punch people in the face. It’s a nice, natural, visceral strike, and a really stupid one. Boxers and UFC fighters target the face because they’re wearing fiberglass armor over their hands. This is there to protect the bones in their knuckles. Without that armor, blows to the face are very hazardous to the attacker; there’s an uneven and fairly sturdy bone structure, which will wreck your bully’s hand.
I just got through talking about concussions, but the other thing near your face, and your character’s face, is their forehead; also known as the single thickest part of your skull. Punches to the forehead are, singularly ineffective. In turn, head butting someone in the face is a very effective technique in the rare situations where it’s viable. It’s also an easy and natural reflex to duck your forehead into the path of an incoming punch.
The other kind of tissue that’s almost as good at protecting internal organs is fat. Body fat will absorb some of the force of a blow. It’s not as effective as tensed muscles, but it’s actually harder to beat someone who’s overweight than someone who’s physically fit. This also includes the breasts, though there are some other factors at work there. I know Michi just did a post on them earlier today, so there’s probably going to be a more detailed write-up of them in the future.
We’ve had a post on bullying in the works for awhile, though the move did a number on our rhythm, so it might be a bit before that one’s ready to go up.