Intro: Can I have some real hit points, please?

As we all know, D&D has that "hit point thing" going on. I'm not here to put it down or even debate it. In fact, I'm fine with D&D hit points as some opaque, totally unrealistic luck-plus-heroics-plus-partial-defense cinematic furball, as long as the game presents it as such, and players accept it as such. I wouldn't design a new game, even a cinematic fantasy one, using hit points in the same way, true – but still, where's the harm?

It's hard, though, to like the tremendous disparity in hit points, especially at first or second Level. Any "normal" human, even a beginning PC (hero material, mind you!), is quickly dispatched by anything resembling combat. Even, infamously, a tussle with a house cat.

When I heard years ago that D&D 3rd edition was coming, I had a small idea for making low-Level hit points more palatable. Now, I'll admit I'm way out on a limb with this one. I haven't even played D&D since its "Advanced" days, and for all I know, my "suggestion" below is already widely discussed (and debunked?), or house-ruled, or even an official part of some other d20 offerings. And it's only an idea for a rules nugget, needing fleshing out by an actual D&D player.

But with nowhere else to record this idea, here it is:

The rule

Starting HP for any Level 0 character equals Constitution.

For large and small creatures, multiply Starting HP by the Carrying Capacity multipliers (Player's Handbook p142), rounding up.

On top of starting HP, add normal Level-based HP.

Variants and options

Would negative Starting HP make a good death threshold, rather than a flat -10 HP? (Or am I misremembering that -10 from older versions and/or legend?) I don't have the answer, so discuss among yourselves.

When to use it

This is intended to inject some GURPS-like sensibility into the HP matter. All creatures will gain sensible – dare I say "realistic"? – minimum HP, determined by overall size and health. Even huge monsters will automatically have appropriately impressive HP, with or without high levels to boot.

Yet Levels will continue to pile on their usual added HP, representing luck and defenses and what not. You'll still achieve astronomical HP in high-Level PCs, if a more modest multiple of "normal" human HP.

Overall, it seems a naturally good idea for a D&D game, leaving fewer Level 0 peasant bodies in Garfield's wake. Yet there's a big piece missing:

Status

It's nothing more than an idea; I haven't played it. And before anyone does, a D&D rules whiz should examine it with an eye toward game balance at low Levels. Is an overall little boost in damage (for weapons, spells, punches etc.) called for, now that low-Level humans have HP 10 instead of 3 or 4? Or are swords and knives still sufficiently dangerous to HP 10 normals? I'm not a good judge.

Designer's notes

Nothing more!

Conclusion

I'm curious: do "d20 Modern" or other variants already use HP based on Constitution or Strength or some such, rather than D&D-like Level alone? If so, then I'm only re-creating an existing idea; sorry.

In any case, I'm glad to finally write this down. :)