Flat MR blues on Mages: Core or not?

[quote=OTGBionicArm]So, I was watching a video by What the Moose (he owns the top Viktor guide on LolKing) and he was talking about something I was always curious about but had never asked about. He goes on a tangent in the video about nearly everyone running Flat MR blues on mages, sometimes even against non AP mid laners. He said it's highly necessary, unless against specific heavy burst match-ups like [[LeBlanc]], as a given example. His math stated that MR Blues increase your damage reduction from 23% to 31% (I'd need to check this in game) and that 31% DR is roughly 6 damage off Annie's base Q damage. He then goes on to praise scaling AP glyphs as all around more powerful on many mages. So I ask you, MOBAFire. What do you think of this? How do you personally feel about the math and other options available? Is there another rune you would use over MR or scaling AP? Discuss below! I'm not sure if we've had this discussion before, but it can't hurt to have it again I guess. Also, I thought it would be better in a discussion format than a question on the front page. Thanks everyone![/quote]

[quote=Vynertje]I would always run them against mages, because I don't see the benefits of other runes over these: Fact is, flat magic pen is more effective the lower MR your target has (because of the negatively exponential scaling, correct me if I'm wrong: the first 30 MR points are more useful than 100-130). Taken that you start with 20 mr after Mpen reduction, the 12 extra MR will mean a lot more than if you have 30 mr and get it to 42. I personally have always felt like having no MR glyphs really makes a noticable difference in the damage you recieve in lane. Scaling AP glyphs (or scaling MR glyphs!) aren't bad at all though, I just wouldn't recommend them when you're playing against any AP mid. EDIT: I misread the poll, I thought the third option meant 'I don't see a reason to take X runes over flat mr' - count me in as 'core'.[/quote]

[quote=OTGBionicArm]Yea, I generally use them myself against any AP. I use scaling AP against AD mids. I was just curious because I never actually asked anyone [i]why[/i] most people run them until I watched that video. On a semi-related note does anyone else run Armor/MR quints against rough match-ups? Edit: ON A VERY RELATED NOTE: %Pen will no longer function against base armor/MR values in S4, will this affect which runes will be used the most?[/quote]

[quote=NicknameMy]1 MR increases your effetive magic HP by 1%. Means flat magicpen has everytime the same effect.[/quote]

[quote=OTGBionicArm][quote=NicknameMy] 1 MR increases your effetive magic HP by 1%. Means flat magicpen has everytime the same effect. [/quote] I feel like this statement is worded oddly... Can you explain the last part with a little more detail?[/quote]

[quote=NicknameMy]Every 1 point of MR is worth 1% of effective HP. Means if you take away 1 MR, you also take away the 1% effective HP you added before. This similar to the fact that stacking armor and magic resistance has no dimishing returns.[/quote]

[quote=luizdeh]I run MR/lv glyphs. Never bothered with Flat MR because they are outscaled too fast to my liking. I take them even if I'm against, say, a [[zed]], if the other team has AP jungle and top, like [[elise]] or [[evelynn]] and [[rumble]]/[[kennen]]/[[vladimir]]/whatever. My reasoning is simple: what good am I if I'm dead? So I forgo a little damage increase for survivability and try to focus on damage items.[/quote]

[quote=Kinen]I find a notable difference between the relative damage I deal to foes with and foes without those MR glyphs. If I were a bit more ballsy with Orianna then I'd be snowballing off most lanes I encountered without those glyphs in rankeds. As it is, such opponents find themselves getting pretty heavily poked. Not only does it make it easier to poke them down and start zoning more heavily, but it also gives me a greater window of health in which I can kill them. This effect is perhaps less extreme against those I face in normal, where I less frequently have a notable skill advantage, but I definitely feel that so long as I remain aware of opponents who might be trying to cheese with doran's starts and a tonne of AP runes, I have a definite advantage. If you're in a matchup where you are sure you can get plenty of free harass and generally avoid taking damage in lane then I could see AP glyphs as being of increased value, but even in such a situation the lack of resistances leaves you more vulnerable to all-ins and ganks. Even if my jungler is physical damage based, I get kills from ganks more frequently when I have that little bit of extra damage.[/quote]

[quote=Thatdudeinthecotton][quote=NicknameMy] Every 1 point of MR is worth 1% of effective HP. Means if you take away 1 MR, you also take away the 1% effective HP you added before. This similar to the fact that stacking armor and magic resistance has no dimishing returns. [/quote] This actually got me curious, so I did some quick looking up and found this video which describes armor/Magic resist pretty well, essentially repeating what you just said, with a couple of other minor points (talks about mr+armor: [embed=http://www.youtube.com/watch?v=uCGExN1nJxM] TLDR: 1 point of MR / Armor both provide 1% effective hp for said damage type. This also means that champions who have a high base health can get ALOT more use outof their armor than those with low base health. It also means that armor / Mr has no depreciating value, so against an all ad team, it would be fine to just stack armor and ignore health items.[/quote]

[quote=OTGBionicArm]That's all fine and helpful but let's try to keep on point with the subject of the thread. :p[/quote]