TheUnholyWrath
commented
4 days ago Magic Resistance is calculated multiplicatively, not additively. Against a hero with 0% magic resistance, like this storm standing next to an Elder Titan, it gets reduced the full 15%. Against a hero with an amount of magic resistance, that value of 15% reduction will be diminished by that magic resistance but the hero will still take 15% more magic damage. You can think about it like this: if Invoker has 40% magic resistance, any magic damage I do to him will currently only do 60% of the damage. If Invoker is then affected by SF ult he's taking 15% more magic damage on that 60% damage we were doing to him previously, so we're doing 69% damage to him now (that's where the 9% comes from). So instead of dropping from 40% to 25%, Invoker's magic resistance goes from 40% to 31%. The wiki explains this better and has some other example if this is still confusing https://liquipedia.net/dota2/Archive:Magic_Resistance
Ability name
Requiem of Souls
Description
So. Requiem has
. I noticed that Requiem does not provide MAGIC RESISTANCE REDUCTION as much as it should. He's acting very strange. It is written that it gives clear values of 5%/10%/15%. Only when I press Requiem, I understand that it gives not so much, but this much: 3%/6%/9%. I tried this in the lobby and it's correct. It gave exactly 3% - 9% MAGIC RESISTANCE REDUCTION. I don’t have a match ID in which you can check this fact, but you can check it yourself. I just can't upload a video that weighs more than 10 megabytes to GitHub.
Invoker has 40% MAGIC RESISTANCE: 
Now i press Requiem on Level 1: 
He has 37% now???
Okay. Requiem Level 2: 
He has 34% xd.
Requiem Level 3: 
Please fix this as fast as possible!!!!
Example Match ID (and possibly Timestamp)