There’s a problem with healing and hps from the start.
• They fail to render the fact that being wounded doesn’t stop a trained combatant to rest and resume combat the next day without problem after a more difficult wake up that usual, provided the wounds are not too serious (or critical in game term), if you do not allow to recover all hit points during a long rest.
• They also fail to render the fact that some wounds are so serious that they won’t allow even a trained combatant to resume combat unhindered without stopping all strenuous activities, often for days, if you simply allow to recover all hit points during a long rest.
Edit : Wounds, here, are as abstracted as hit ponts. I could (and should) have said loss of hit points instead.
If you favor one of these two points, you leave all realism behind. The first point has the minor drawback of turning the adventurers into super-heroes like Spider-man that can heal any wounds overnight. The second point has the severe drawback of putting all the ability to simply go adventuring in the hands of a sacrificed player, the legendary healing bot.
I think it’s possible to solve these two points without going back to video game critical hits from 3rd and 4th editions (my favorite editions ! I don’t want to start an edition war !), with thunder, lightning and go-go dancers when you roll a natural 20 with a big weapon.
The idea is to keep simple hit points as an abstraction and simple critical hits as max damage.
The added complexity is to keep track of the critically lost hit points.
Hit points lost by critical hits cannot be recovered overnight and need special care. Other hit points losses are recovered after a good sleep.
From the critical hit point of view itself, it could be interesting to render the physical shock by having disadvantage on the next roll within one or two rounds.
Edit 2 : Death: a minor point I forgot to adress
Zero hp or less by normal loss of hit points : incapacitated with no risk of death by itself.
Critical wounds equal to max HPs: instant death.
All damages while at zero or less hp are considered critical wounds.
Zero hp or less by a mix normal loss of hit points and critical wounds : you (critically, see above) lose one hp per round.
It’s the kind of hit points management I would like to see in the next edition. Even if it’s an added complexity for players, it doesn’t impact much the DM side and can keep us from the DREADED HEALING BOT with some alternate options depending on the nature of the wounds.