Understanding Impair ("脆弱") ​

tags: impair

1. Enemies have DEF. Many Ex MA bosses have DEF = 996. The result of DEF on damage is that a factor of 1 / (1 + (DEF / (300 + 20 * lv))) is multiplied to any damage when the damage is physical. This multiplier is called phys resist effect. lv is the level of the attacking valk. I'll use lv = 80 for this FAQ, thus phys resist effect = 1900 / (1900 + DEF). For example, when DEF = 1000, phys resist effect = 0.655, i.e. 0.655 is multiplied to any physical damage.
2. If it helps, 1 - ele resist = ele resist effect is multiplied to any ele damage just like how 1 - phys resist = phys resist effect is multiplied to any phys damage.
3. Impair is a reduction in DEF, i.e. Impair is a percentage that is deducted. Let's say Impair is 75% (e.g. CH Ult), so where DEF = 1000 before Impair, now DEF = 250 and phys resist effect = 1900 / (1900 + 250) = 0.884.
4. 0.884 is a lot better than the 0.655 from before Impair! We can also deduce that dmg increase as a result of impair is Impair * DEF / (1900 + (1 - Impair) * DEF). For DEF = 1000 and 75% Impair, that's 750 / (1900 + 250) = 0.349, which makes sense, as 1.349 * 0.655 = 0.884.
5. Impair is always expressed as a percentage. As far as is known, all sources of Impair replace previous Impair, except when it says "Impair only when not Impaired", in which case it does nothing. (Only 1 source of Impair can be alive.)
6. BONUS Herrscher of Sentience's ultimate can be thought of as constantly refreshing it's own impair, thus it takes priority over any other impairs that might be applied for it's duration.