Hit points are a small integer pool, and damage is rolled — you lose them in chunks, never on a smooth drain. Losing all of them is death; losing your vigour only puts you on the ground.
Nothing comes back for free
Hit points do not regenerate on their own. Mending is the only source: a channelled cast, kept on the beat while you touch the patient. The load is a low one, which means a botched mending is a short circuit — burning a body is far easier than knitting one.
Falling
Fall damage is measured once, at the instant you land, from how fast you were moving down. There is no accumulated "fall meter" — a long drop you break halfway down is two short drops.