Hearts

==Red Hearts==
1: 
Exceptionally frail.
Day-to-day tasks can be dangerous and small wounds will likely cause death. Individuals with one heart usually suffer from a debilitating illness or are exceptionally old.
2: 
Physically frail.
Number of hearts attributed to an elderly or somewhat sickly individual that can't perform or survive basic combat without considerable assistance.
3: 
Low body mass and/or small frame.
Attributed most to physically weak individuals and typically female characters.
4: 
Standard body mass.
Most males and females are attributed this many hearts. These individuals have average to above average toughness for an adult. Females with this many hearts are usually tough, even for their weight class.
5:
Characters with above average body mass.
Generally attributed to males with a muscular or physically fit build whose extra muscle or endurance allows them to take significant hits. Characters in this bracket can suffer from wounds that would quickly down a character with four or less hearts, such as a gunshot.
6:
Borderline-superhuman toughness. Able to take exceptionally hard hits.
These characters can endure even bullet wounds and continue fighting unhindered. However, they must still heal themselves or be medically treated in order to survive. A typical human can only reach this if aided by drugs or other abnormal circumstances.
---Everything below this line is a very rough estimate---
7:
Superhuman durability.
Beyond what even the toughest human can attain, even through unconventional scientific aid such as powerful narcotics. Can take direct shots from small arms fire and will be nearly unimpeded. Explosive and military ballistics will take them down, however.
8:
Exceptionally durable supernatural being.
Brushes off most military-grade weapons but can still be damaged by high yield explosives. May still flinch from direct shots from bullets and other small arms if they don't brace themselves. Can be harmed by exceptionally powerful ballistics, like a tank, but still may be able to recover without external aid.
9:
Supernatural durability that borders on invulnerability.
Characters attributed this many hearts are able to withstand even military grade ballistics without difficulty or assistance. Can withstand direct and maintained fire from high-grade large arms fire, such as miniguns and rockets without effort. Nothing short of a high yield explosive will impede or harm them, with a direct hit being able to possibly kill them.
10:
Durability that borders on complete indestructibility.
Can survive any conventional weapon, with nothing short of a direct nuclear strike being a mortal blow.
11:
Virtually indestructible.
Even nuclear-grade military weaponry would be ineffective.