Void Staff and Last Whisper have percentage penetration. At first, noob that I was, I thought that a percent increase to damage. But then, I noticed on squishies it did next to nothing if I instead got Will of the Ancients or Maw of Malmortius.
So, when you go to calculate penetration damages is it
Damage Dealt= ((Armor OR MRes)/ Void/Whisp - other penetration) + (Damage of attack)
IE DMG= (256A/35%-30Apen) + 398?
Did that make sense?
Kuroi861 votesLast Whisper and Void Staff are for dealing with tanks who have built a significant amount of resistance against your damage type.
When dealing with low levels of resistances, flat pen is better.
Kiharon1 votesFrom http://leagueoflegends.wikia.com/wiki/Armor and http://leagueoflegends.wikia.com/wiki/Armor_penetration
Replace Armor with Magic Resist and associated penetration/reduction for magic damage
Damage taken = Listed Damage * 100 / (100 + Armor)
Some key values then are:
Armor: 50; Damage taken: 67% of listed Armor: 100; Damage taken: 50% of listed Armor: 200; Damage taken: 33% of listed Armor: 300; Damage taken: 25% of listed
Armor in that calculation is:
Effective Armor = (Listed Armor - flat armor reduction) x (1 - % Armor Reduction) x (1 - % Armor Penetration) - flat armor penetration
So suppose you have Last Whisper and armor penetration marks. This changes the key values to:
Listed Armor: 50 -> Effective Armor: 50 x (1 - .35) - 11.52 = 20.98; Damage taken: 83%; Damage boost from penetration: 57% (In this case, the flat penetration is helping almost as much as the %) Listed Armor: 100 -> Effective Armor: 100 x (1 - .35) - 11.52 = 53.48; Damage taken: 65%; Damage boost from penetration: 30% Listed Armor: 200 -> Effective Armor: 200 x (1 - .35) - 11.52 = 118.48; Damage taken: 45%; Damage boost from penetration: 39% Listed Armor: 300 -> Effective Armor: 300 x (1 - .35) - 11.52 = 183.48; Damage taken: 35%; Damage boost from penetration: 41%
The referenced pages give more charts and details.
67chrome1 votesVoid Staff and Last Whisper have percentage penetration. At first, noob that I was, I thought that a percent increase to damage.
They basically are a %increase to damage.
They're one of the key secondary multipliers for ability damage. You can quickly run into situations where you have to much AD/AP for more to be cost-effective and penetrations will see a larger, more cost-effective bonus to skill damage.
Mix flat and %penetrations together and both wind up being more %damage increases then countermeasures to defense.
Also, average level 18 armor is 75. Karthus and Miss Fortune hit that with no help from runes, masteries, or items. Most squishy champions get a little more defense from runes, masteries, and items.
In the level 15+ zone (3rd major item), all %penetrations are pretty solid against enemy champions. Also, without void staff or last whisper on committed physical or magic damage champions, it's insanely easy to counter-build such champions with something like Thornmail or Banshee's Veil, which is never a situation you want to find yourself in.
