[Question] Magic Penetration

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Teru

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Senior Member

03-19-2010

I got a question about how magic penetration works lets say you got the Sorcerer's Shoes -20 resist and Void Staff -40% resist the enemy has well lets say 100 Magic resist Void Staff takes it down to 60 and then Sorcerer's Shoes takes it down to 40?
Or is it 100-20=80 then -40% to make it so he has 32 magic resist?

Never really understood how it worked exactly if anyone knows 100% would very much like to know


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EmissaryShadow

Emissary of the League

03-19-2010

http://www.leagueoflegends.com/board...ead.php?t=3287 Magic Pen and armor pen work the same way.


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RHINO Mk II

Senior Member

03-19-2010

Armor/Magic penetration works in this order:

1) Armor/Resistance flat reduction by items such as abyssal scepter (MR reduction aura) or spells such as Ryze's spell flux (-15 MR per bounce) or Nasus's Spirit Fire (Armor reduction AoE) or Fiddlestick's passive (MR reduction Aura)
2) Armor/Resistance percentage penetration by masteries such as Archaic Knowledge (15% magic penetration) or items such as Void Staff (40% magic penetration) or Last Whisper (40% armor penetration)
3) Armor/Resistance flat penetration by runes such as Insight or Desolation (Resistance and Armor penetration) or items such as sorcerers shoes (20 magic penetration) or the Brutalizer (15 armor penetration)

Example: Your enemy has 100 Magic Resistance. You are a caster with the Archaic Knowledge mastery and 9 marks of insight. During the game, you purchase Sorcerer's Shoes and an Abyssal Scepter. The calculation looks like this:

100 MR - flat reduction (20 AoE reduction from Abyssal Scepter) = 80 MR
80 MR - percentage penetration (15% penetration from Archaic Knowledge) = 68 MR
68 MR - flat penetration (8.5 penetration from marks of insight and 20 penetration from sorc shoes) = 39.5 MR

When the enemy is stacking MR like this, Void Staff can be a better choice than Abyssal Scepter:

100 MR - flat reduction (0 since you changed your build) = 100 MR
100 MR - percentage penetration (15% from Archaic knowledge and 40% from void staff) = 45 MR
45 MR - flat penetration (8.5 from runes and 20 from sorc shoes) = 16.5 MR


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Teru

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Senior Member

03-19-2010

thank you for the info it really helped with my choice in item item setup.