Dying

The creature is on death's door and about to die.

It is Unconscious.

Death Saving Throws

Each turn the creature has this condition, it must pass a Death Saving Throw by rolling a 20-sided die :
If the roll is equal to 10 or higher, it succeeds. Otherwise, it fails. On the third success, the creature becomes stable. On the third failure, the entity dies. The number of both is reset to 0 when the entity regains HP or becomes stable. On a Natural 1, it counts as two failures. On a Natural 20, the entity regains 1 HP and loses this condition. Taking any damage while having 0 HP adds one failure to the Death Saving Throw. Taking a Critical Hit adds two failures. If the damage equals or exceeds the entity maximum HP, it dies instantly.

Stabilizing

When the entity is stable, it doesn't make Death Saving Throws, even though it has 0 HP. It remains Unconscious. If it takes damage while stable, it stops being stable and must make Death Saving Throws again. A stable creature that isn't healed regains 1 HP after a number of hours equal to the result of a 4-sided die roll.
This condition ends once the entity dies, or if they regain any HP.