I didn't fully understand the calculation used in this part: "If a unit is damaged, its damage values will be decreased. (20+x.0,8)% is the damage efficiency of the unit, where x represents the health percentage of the unit. In other words, the damage efficiency is 100% for a full health unit and will go down as the unit is damaged, ending at 20% when the unit has zero hp (is very close to zero)."