So far the two winning options are essentially the same. Either healing always starts from zero or hit points never go below zero (therefore healing always starts at zero).

Is this a commentary on mathematics? Negative numbers are annoying?

Negative hit points are kind of like THAC0. They work mathematically, and can be visualized effectively on a number line, but require two levels of abstraction.

The first level is that negative numbers are, in fact, an abstraction. We can visualize positive numbers as physical objects. They can be counted. But negative numbers only exists in comparisons and rate of change. They never represent static objects, so our visualizations of them require false abstractions.

The second level is to then apply negative numbers to represent how close you are to being dead. So, as you take further damage, you're mathematically counting down, but mentally counting up.

All these mental gymnastics are uncomfortable, even if they aren't that difficult.

In defense of negative hit points, the current system is very simple when looked at as a health bar:

HP: *ooooo ooooo* | ooooo ooooo ooooo oo (17)

Start at the right. That's full health. When you reach the line, you're disabled. When you reach the end, you're dead. It's only when expressed in words that the concept becomes annoying.

One thing we can do is simply give negative hit points the THAC0 treatment. Make them positive. Call them wound points. When you run out of hit points, you start taking wound points at the same rate. When you run out of wound points, you're dead. It's functionally identical, and more clearly represents something.

At the same time, it

*seems* like a separate mechanic. A complication. Especially in a world filled with games where running out of hit points means you die. But it's clear that most people want something between fully able and dead. That requires some level of complication.