How does Magic pen work?

First Riot Post

Senior Member

Quote:
Originally Posted by Phreak
You're asking for some math as well, so here goes:

First, % penetration works first. So if I have a Void Staff/Last Whisper, I pretend your MR/Armor is only 65% of what it really is. Then I factor in things like Brutalizer/Sorc Shoes/Haunting Guise. Those things work additively. So for example, if you had 200 MR and I had Void/Sorc/Haunting, Void reduces 200 to 130, then Sorc/Haunting reduce that 130 to 100.

So instead of dealing 1/3 damage (fighting 200 MR) you deal 1/2 damage (fighting 100 MR). Thus, the passives result in you dealing 50% more damage than before.

Note that penetration can only go so far. What I mean is that, if you have exactly 100 flat magic pen, it will only give you at most 100% bonus damage (your opponent has 100 MR). If your opponents have any more or less than 100 magic resist, you will get slightly lower returns.

Example: You have 100 MR, so I deal half damage. With 100 magic pen, I deal full damage, aka double what I would have before. If you have 200 MR, I deal 1/3 damage. I reduce that with my 100 magic pen to 100 MR, and I now deal 1/2 damage, so 50% more than before. If you have 50 MR, I deal 2/3 damage. With 100 magic pen, I deal full damage, or 50% more than before.

I hope those all made sense.

Mathematically this isn't true; they roughly equal out. If you had 80 base armor and bought Thornmail, and I bought Last Whisper, your armor went from 80 to 180, then I reduced it to 117. Obviously we each got some extra stats (damage return, 40 AD), but it's pretty easy to see that while % pen is useful, it does not completely devastate tank items.
54367

so he gets a black cleaver. Now what.

66% and 10flat. now they have 62, and I have enough health to toe to toe any tank/bruiser with just those two items and a BT. Yea np, you should be able to tear up any champ if you have 3 items.

O and I notice you didn't say anything about the AP MrPen. I posted

Phreak

Shoutcaster

Quote:
Originally Posted by Registeel1234
First, you need to understand how defenses work. Magic resist reduce the damage taken by a percentage. The formula is this : MR/MR+100

So, for exemple, if you have 100 MR, you get 50% reduce magic dmg (100/200 = 0.5)

%MRPen reduce the MR first. So let's say you got void staff (35% MRPen) and that your enemy has 100 MR. You reduce that MR by 35%. So your enemy get 65 MR after your MRPen (100 - 35 = 65)

But if you also have flat MRPen, you remove a flat amount of MR after the %MRPen. So if you also have sorcerer's, your enemy get 50 MR after voidstaff and sorcerer's (65 - 15 = 50)

After MRPen, the game reduce the MR from debuffs and items (Dread, starcall, ect...). Again, it reduces MR by a flat amount.

So the order is : %Pen - FlatPen - DefenseReduce

I't the same thing for Armor

EDIT :

Yes, it's true, MRPen cannot make you more dmg than normal. However, defense reduce, like starcall can make you deal more dmg than supposed to.
Defense reductions come first. They affect the base armor/mr value

AR Manimal

Senior Member

Quote:
Originally Posted by Phreak
Mathematically this isn't true; they roughly equal out. If you had 80 base armor and bought Thornmail, and I bought Last Whisper, your armor went from 80 to 180, then I reduced it to 117. Obviously we each got some extra stats (damage return, 40 AD), but it's pretty easy to see that while % pen is useful, it does not completely devastate tank items.
It feels pretty devastating when I'm the tank. But when I have LW or VS I still feel like a kitten gnawing on a steel-toe boot.

Idk, I guess I just suck.

Irelia Bot

Senior Member

Well it might have some opinionated things on it but I do explain this and give an example in the section labled "Some other stats that are worth knowing"

http://www.lolking.net/guides/edit/70054

Biggg O

Senior Member

[QUOTE=Phreak;43607881]You're asking for some math as well, so here goes:

First, % penetration works first. So if I have a Void Staff/Last Whisper, I pretend your MR/Armor is only 65% of what it really is. Then I factor in things like Brutalizer/Sorc Shoes/Haunting Guise. Those things work additively. So for example, if you had 200 MR and I had Void/Sorc/Haunting, Void reduces 200 to 130, then Sorc/Haunting reduce that 130 to 100.

So instead of dealing 1/3 damage (fighting 200 MR) you deal 1/2 damage (fighting 100 MR). Thus, the passives result in you dealing 50% more damage than before.

Note that penetration can only go so far. What I mean is that, if you have exactly 100 flat magic pen, it will only give you at most 100% bonus damage (your opponent has 100 MR). If your opponents have any more or less than 100 magic resist, you will get slightly lower returns.

Example: You have 100 MR, so I deal half damage. With 100 magic pen, I deal full damage, aka double what I would have before. If you have 200 MR, I deal 1/3 damage. I reduce that with my 100 magic pen to 100 MR, and I now deal 1/2 damage, so 50% more than before. If you have 50 MR, I deal 2/3 damage. With 100 magic pen, I deal full damage, or 50% more than before.

I hope those all made sense.

Makes sense. Thanks.

Vampaloo

Junior Member

I'd like to talk to whoever does the mechanics of the game. Because its quite clear that if you play with your screen locked, which alot of people do coming from other games that auto lock on your toon.... If your on the bottom left, blue team.. You only have a score frag chart, very tiny doesn't block anything...You can see everything and land your attacks with ease...Do to, being on top right lane, purple team... You have skills directly below your toon, which is often covering the grass halfway to your champ visually... items and stats on the bottom left, which is blocking the rest of the lane, where the blitz grabs stuns and inc attacks come from, same with grass... Mini map also blocks the grass... Yes you can move it from the right to the left, so block the view of the grass and stuff coming out of it or block the middle of the lane?... It is very unfair, and I've noticed a clear difference in win ratio... From having almost an entire screen of view to dodge or land attacks vs being only a an inch or two from interface controls like the skills bar... Would be easy to fix, tilt the map straight left and right like 3v3.... would help alot... or make some of the stuff transparent or minimizable or let it be flipped to the top of the screen? Something has to change, because it is ruining the game play.

Rivini

Senior Member

Doesn't % pen only work on bonus armor and magic resistance now? Or was that not put in yet?

Misara Hirama

Senior Member

Quote:
Originally Posted by Artaean
It feels pretty devastating when I'm the tank. But when I have LW or VS I still feel like a kitten gnawing on a steel-toe boot.

Idk, I guess I just suck.

A tip, lots of people rush LW or Armor pen in general against armored foes, Taric/Rammus come to mind, before damage. Even more are like Ezreal, who get Trinity, rush it no matter what, then rush LW. You can have 100% armor pen but if your only doing 150 a shot, you will only do 150. Tanks generally build items that give them HP AND Armor, you need damage to back up the Penetration, otherwise it really doesn't matter.

100% Of 0, is still 0 so to speak.

Arkaia

Senior Member

I usually get pen as my fourth or fifth item as my major damage dealing characters, at that point I've acquired enough AP to where if I bought pen I would be doing a lot better damage right as other people are finishing their build. If I'm ahead, it lets me nuke people for a while until they get resistances.

Kokoroyer

Member

Quote:
Originally Posted by Tesla23
they work like this:

tank spends +10k on tanky stats.

squishy gets a single 3k item.

Tank now has no stats
So a lot of people are hating on this guy's comment and I just wanted to say I find it absolutely hilarious. +1 :P