In battle, the goal is to defeat your opponent without being defeated, yourself. If you can attack your enemy and they cannot retaliate, that goes a long way to victory. For House Stark, that means employing skilled bowmen in their ranks. They have trained relentlessly in their everyday lives as trappers, rangers, and hunters.
Some men just relish confrontation. They long to jump into the fray, scrapping with an enemy, seeing them beaten to a pulp. As the battle rages on, they get more and more into a frenzy. Wounds seem to not matter and actually drive their bloodlust further. That’s the case with the Umber Berserkers. Once battle is met, it only ends when either they or their enemy are no longer moving.