Talk:Magic resistance/@comment-78.52.243.127-20111006180722/@comment-78.53.24.31-20111009110852

The math is just fine. You have to consider the hp of your champ to get the effective health. You just took a random amount of damage: 1k in your example. Lets say your champ has 1000hp as in the example above. If he has 500MR you have to apply a total of 6000 magic damage to kill him. If he has 510MR you have to apply 6100 magic damage to kill him.

In your example with 500mr you have to apply the 1000magic damage (1000hp/166,67)=6 times to kill. And with 510mr you have to apply the 1000magic damage (1000hp/163,93) =6,1 times. Which means in first case the caster needs to apply 6000 damage and second case 6100 damage. thats the difference of 100 effective hp. If you buy a pure health item you have to multiply the health aswell to get the correct gain in effective health. Additional Healthitems lead into a effective health bonus depending on you magic resist. And magic resist gains you an effective health bonus depending on your total health. At a certain point its better to buy health than more magicresist.

Lets do an example. I play rammus in dominion -> base stats at lvl 3. 764 hp. I got 30 MR. (i dont consider enemy mr reduction skills). My effective health is 993,2. Giants Belt will give me 430 hp leading into 1552 effective health. Negatron Cloak and Nullmagic mantle will bring 72 additional MR. my effective health would be 1543. Its almost the same price and nearly same result. Giant belt will bring more effective health for physical damage aswell.

This effective health thing is only good for one type of damage except you know how much of the damage applied is magical or physical. Correct me if I'm wrong.