A creature brought to zero hit points has been defeated and can no longer fight. If brought to zero hit points by a lethal weapon, they are dead or dying. Foes brought down with fists, blunt objects, or other less-than-lethal means may merely be unconscious or incapacitated, if their assailant wasn’t trying to kill them. Some enemies might even be incapacitated by purely mental or emotional strain. Foes defeated non-lethally recover one hit point after ten minutes and then function normally.
A mortally-wounded creature at zero hit points will die in no more than six rounds. They may be unconscious, screaming for their mother, trying to press vital organs back into place, or begging for mercy, but they can perform no useful action and their fate is sealed if no immediate aid is provided. Creatures dropped by Heavy weapons, explosives, or other dramatic injury may be instantly killed at the GM’s discretion. Additional damage inflicted on a mortally-wounded target will always kill them immediately.
A PC who wants to extend mercy to an enemy or aid to a friend can use their Main Action to attempt an Int/Heal or Dex/Heal skill check, using whatever modifier is best. If they have no special medical tools available at all, the difficulty of the check is 10 plus the number of rounds that have passed since the target went down. If they have a medical kit or other proper trauma tools, the difficulty is 8 plus the rounds since injury, and if they expend a Lazarus patch on the target, the difficulty is 6 plus the time. A failed check can be re-attempted next round if the target isn’t dead yet, but Lazarus patches are expended even on a failure. The Biopsionic technique Psychic Succor automatically succeeds in stabilizing a target, if any time remains to them.
A critically-injured target who has been stabilized regains one hit point after ten minutes of recovery.
They are able to move and function normally if they are fiercely determined to do so, but any further damage whatsoever will kill them, with no chance for stabilization. If they are healed with some high-tech pharmaceutical stim or advanced Biopsionic technique, they can shake off this fragility and return to action with whatever hit points the drug or power have provided.
Without such advanced healing, a critically-wounded target requires at least a week of bed rest and medical care before they can shake off their fragility and start regaining their level in hit points after each night’s rest.
This assumes that TL4 medical care is available. If only TL3 tech is on hand, the recovery time is a month.
If TL2 or lower medical care is provided, the recovery time is a month, and the target must make a Physical saving throw at the end of it, with a bonus equal to the Heal skill of whoever is tending them. On a success, they’ll recover within 1d4 more weeks. On a failure, the primitive technology ensures they’ll die of their wounds at some point in that time.
Creatures that have suffered damage but have not been mortally injured regain hit points equal to their hit dice or character level after each night of good rest.