Look again.
It's (0 - Damage). Negative Damage.
The way the engine works is just a switch that toggles back and forth throughout the processing of the attack.
Various things can reverse damage polarity, and when the damage is reversed during processing, the processor doesn’t actually change the damage each time. Instead it just toggles a switch, true false true false, etc.
At the end of the damage calculation (rather, NEAR the end), it checks the switch to decide whether to deal damage or heal.
Healing is just dealing negative damage, which is (0 - Damage).
Any attack with an element of “Restorative†will toggle this switch once. In most cases, the switch won’t be toggled again and the damage will be negative, causing the healing effect.
If you get hit by an element you absorb, the switch is toggled once.
If the attack is “Restorative†and you absorb “Restorativeâ€, the switch is toggled twice, and thus set back to normal, and the final result will deal damage instead of health.
This is why it is inaccurate to say “+HPâ€, since it can be damage instead of health.
So, (0 - Damage) it is.
James Pond, it is just for lack of better wording.
L. Spiro