Let me start off by saying I know going glass cannon runes is not ideal, not here to debate that.
With all teir 3 runes for AP, magic pen what in your opinion is the highest damage setup for early burst (not interested in scaling). I have tried 15ap/15magic pen (like having sorc boots at level 1) and many other combos. More ap? More penetration? What is more damaging for early game?
If your champ skills has high base damage and low ap ratio you should go for pen. Else flat ap.
Depends on your ratios. Karthus and Rumble gain more damage going with 20 flat magic penetrataion by level 7, when the base damages outscale flat AP.
Karthus has a 60% AP on single target Q and 30% on multi target Q. Since people love to stand in creep waves to avoid being crit Q'd, all pen is going to hit harder by the time you have three points in Q.
Defile has a 20% AP ratio so it benefits heavily from magic pen.
Depends on the champ you're using and who you're trying to burst. (Sorry, not a simple answer!)
Yeah karthus can go for either. The benefit of going for pen is it's cheaper than going for a deathcap build (since you also need a zhonyas and a seraphs and those are all big money items). Going for pen on karthus empathizes E (defile) damage and build efficiency (being able to counterbuild their MR with pen)
Champions with high ap Ratios, like Chogath and Annie, benefit very well from the flat AP Runes. You could buy a Doran's for even more AP, and some basic starter stats in hp and regen/passive. Or , with flat AP Runes, buy an Armor Cloth if you're mid laner is ad, or lots of sustains tools to outfarm your laner from the first engage (runes providing the AP you would not have without buying the Doran's) However, if your champ has abilities with high base dmg, magic pen is more effecitve. High AP = Useful magic pen. Low AP = Magic Pen not so important. It's like having tons of atk speed without any ad to back it up. IMO. I can often get a fb as Annie or Liss (ratios not considered) with high AP Flat runes. People don't have mr early on (another reason to go flat ap over magic pen for early advantage) but if you can't snowball the enemy will pick up MR and then it's not a walk in the park.
Scepters. Btw.
