One of the tropes that is often poorly explained in RPGs is hit points. It’s an abstraction that represents how close you are to defeat. But what does it mean in terms of the fiction?
Let’s say you have 20 HP, and an orc stabs you for 5. What does that mean? Have you been deeply stabbed? Mortally wounded? Not really. You have 15 hit points left. So what happened? What did the orc do to you? How have you been brought to 3/4 capacity?
Well, you got hit with a big ol’ sword. So no, you’re not bleeding out. But HP damage is supposed to be relatively easy to heal, right? Instead, HP can be thought of as staying power. HP isn’t actually health. Its an abstraction of fatigue, close calls, and small wounds. Once they hit a certain point you just can’t get out of the way anymore and get a fatal wound.