A very underbaked idea which I'll leave here and most likely never try and use:
There has been for quite some time the concept of temporary hit points - not quite healing, but, hit points that operate just the same. The general definition of the category is that temporary hit points are depleted first - then damage dips back into the regular pool.
What if they didn't? What if you continued to accrue damage to 0 "real" HP, and what kept you standing was the perishable hit points?
- Whatever the source; magic, alchemical, delusional (berserkergang?): perishable hit points are used last - the character is reduced to 0 real HP with subsequent damage, then PHP is depleted - and the character operates normally for as long as the PHP last.
- If 'real' healing, from potion, spell, proficiency, etc. is acquired, any remaining PHP is lost.
- Additional sources of PHP will stack up, from potion, spell, etc.
- PHP cannot push a character above their natural HP limit.
- PHP disappears at a character's first rest period after being applied (rest period as defined by pg 92 of ACKS; 1 turn every 5 turns).
- A character with 0 real HP (operating on PHP only) will need to save vs. Death to "press on" and not rest after 5 turns. A failure removes all PHP from the character. Additional saves after the first take a -4 penalty.
- If a character is left at 0 HP at the time PHP expires, roll on the Condition & Recovery column of the Mortal Wounds table, modified as per table instructions (as HP wll always be 0, the +5 bonus will always apply), with a d20 only. Interpret the results less as actual mortal wounds, but as system shock from the strain on the body at being pushed beyond natural capacity.
- An attack which expends the last of the character's PHP and pushes them to 0 HP or below 0 is treated normally per ACKS rules.
...so, what holes are in this, aside from it being completely unnecessary - I don't actually know what imagined problem I'm trying to solve, so :)
I was looking for something verifiably "cheaper" than "instant magic" healing, more-or-less in order to support a expanded alchemical system for a lower-magic sort of deal - something that's immediate enough to be useful "in combat", but still leaving the main issue of being "out of HP" at the end of a bad fight - still "worn out", it's just that you had a ...sci-fi style stim pack there keeping you going for a bit.
No miracles, only a slight delay in having to deal with the problem. A 14th level fighter has a ...20% chance? to last 4 hours without resting.
And I didn't really want to screw with the default HP mechanic; nor fully eliminate the "game concept" of in-combat healing - and I'd like for "magic healing" to still operate as usual for extraordinary situations. I realize I'm conflating several differing philosophical definitions of "HP"...but.
I'm really not sure how much that's worth, comparatively to the cost values in the PC for Healing - there is obviously a hell of a lot of utility in surviving a fight, if only to be knocked unconscious in the next hour, but, I dunno.
Probably should have something for getting PHP more than once per day (given PHP has expired already once for the character), and characters needed rest according to the MW table can't take more PHP (save or unconscious?)