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### Can someone explain Magic Resist?

Darkazn58

Senior Member

Can someone explain how the calculations and mechanics of Magic Resistance work? I was just in a game as Zilean and I had at least 450 AP but against an Amumu with about 100-120 MR my Time Bombs wouldn't do more than maybe 200 if even that. That is so ridiculous. It takes a lot of gold and kills to get up to 450 AP, but a couple cheap items and I'm completely countered.

What does a caster have to do to get around Magic Resistance? I don't think Abyssal Scepter is viable since I have to be close for that. And Void Staff seems like the only option, but it takes me way off my build.

Abyss Crown

Senior Member

Void Staff...

Those items are there for a reason. You always have to adjust to what each match throws at you, and if you don't then that explains a lot.

SuperStomper

Senior Member

If you have 100 magic resist, you have 100% more health vs magic damage.

100 / (100 + MR) = Reduction

Mercucial

Recruiter

If them stacking magic resist is causing problems, get magic pen.

Having a set build also isn't a good idea either IMO. It should vary from game to game, depending on what items the enemy has and how well you and your team is playing that game.

xephh

Senior Member

Quote:
SuperStomper:
If you have 100 magic resist, you have 100% more health vs magic damage.

100 / (100 + MR) = Reduction

Wait a second, I'm no mathematics major..

But don't those 100's cancel out?

Yobber

Senior Member

Quote:
SuperStomper:
If you have 100 magic resist, you have 100% more health vs magic damage.

100 / (100 + MR) = Reduction

This is a stupid and counter intuitive way to explain it.

100 Magic Resist = -50% damage suffered from magic damage.

Senior Member

You can roll your mouse over your stats to see what they do. For example, if you rolled it over Magic Resist, you'd see the percentage of magic damage reduced (before Magic Pen and Magic Pen %).

Think of it as armor, but for magic.

Also, Zilian is not a good killing hero. He's there for support and his amazing Ultimate that can change any team fight into your favor if used right. Stay back, speed people up, spam time bombs as needed, keep ult going, etc.

Zack1996

Senior Member

If your Zilean build doesn't include Void Staff, the current metagame will eat you alive.

And the amount of damage you take from stuff is:
100 / (100 + MR)
So with 100 MR, Amumu would be taking 100 / 200 damage, 50%.
If he proceeds to stack 100 more MR, it'll be 100/300 damage, 33%.

Which effectively means that:
a) You need to deal 2x the normal amount of damage to kill him, when he has 100 MR.
b) With Void Staff, this amount is reduced. eg. 100/ (100 + 0.6 x 100) = 100/160, which is 0.625%. Therefore, you only need to do 1.6x of the normal damage. Effectively, you need to do 80% of the amount of damage required without Void Staff, so your damage is effectively increased by 25%. The more MR he stacks, the more effective Void Staff is.

S T

Recruiter

Magic Resist is designed in reference to Warcraft 3's armor mitigation, that is:

Up to a certain point, magic resist reduces spells by a percentage. (Same with armor)
With around +100 MR I believe you get close to 50% magic damage reduction, this is why your spell with tons of AP was countered. The way you counter MR stacking as a caster is to get Mpen, which negates that MR. (Therein reducing their percentage reduction)