My name is Ajido, I've always enjoyed playing unorthodox and uncommon champions. I reached Diamond playing primarily Heimerdinger (94W 60L, 61% win rate) and AP Corki (45W 31L, 59% win rate...though many of my losses are from earlier, failed experimental builds that I will go over in this guide). I welcome you guys to add me in game if you have any questions, I also stream at Twitch.tv/Ajido_LoL

My goal with this guide is to be concise but pack in as much information as I can. Feel free to leave comments, questions or suggestions. Thank you!

Magic Penetration
Corki does not have the highest scaling AP ratios, but he has very high base damage on his abilities. For this reason, it is our desire to have as much Magic Penetration as possible.

Armor
Armor is useful at all all stages in the game, even if you're up against an AP mage in the middle lane who will likely exchange auto attacks with you.

Flat Cooldown Reduction
My reasoning for taking flat CDR runes as opposed to scaling is that scaling only offers 2.5% more CDR at level 18. Flat and Scaling runes are not equal to each other until close to level 14, which is very late in the game. With flat CDR runes, 4% from masteries and 20% from Athene's, you will have 31.5% very early in the game which is more than sufficient.

NOTE 1
Scaling CDR runes are perfectly fine if you happen to have them and don't own the flat ones.

NOTE 2
Hybrid Penetration Marks and Quintessences are something I've toyed around with on a separate rune page. Armor Penetration in my opinion is not that useful with this build and play style, and is only beneficial for the very early laning phase against melee champions that are prone to harassment such as Zed, Kha'zix, Kassadin, Akali, etc. Once players reach level 6, exchanging auto attacks becomes a little more risky, by mid and late game the Armor Penetration is virtually useless.

Since AP Corki only really has one damaging ability from levels 1 through 5, I choose to play him 21-9-0 with 21 points in Offense and 9 in Defense to give him as much power in the laning phase as possible. With the starting items I've recommended, no one will be able to push you out of lane before hitting level 6. This build also offers the strongest possible mid and late game.

NOTE 1
You should swap points around in the Defense tree between the Armor and MR, depending on your lane matchup.

NOTE 2
Summoner's Resolve (20 additional shield on the Barrier), is not worth it in my opinion even if you're running Barrier. I would rather just have a slightly higher Armor or MR.

9-0-21 is certainly viable, but makes you squishier in the laning phase and decreases your damage output all in exchange for unnecessary conveniences. Everything in the Utility tree is nice to have, but not needed.

• Mana Regen is not needed since your first item is Chalice
• 10% cooldown reduction on Summoner's is nice but not needed since we have Valkyrie for when Flash is on cooldown.
• Increased duration on Blue Buff is again nice, but not needed by any means.
• Increased XP gain is nice, hitting level 6 slightly before your lane opponent, but not a necessity.
• 6% CDR is nice, but the raw damage from Offense is more important.
• 3% Movespeed is always nice, but Corki has incredible range and mobility with his kit, so this is just a convenience.

In this section, I will explain my reasoning for picking up the items that I do. In the next section I'll give my reasoning against buying other seemingly viable choices. If I don't mention something that you feel is an item worth talking about, feel free to leave a comment.


This is pretty self explanatory. Magic Penetration is our desired stat and no other boots are comparable. I choose the Home Guard enchantment as it is generally the most useful in every match.


20% CDR is huge, having more CDR allows you to store more Rockets faster, allows you to Valkyrie more often. 60 AP will of course increase our damage output, and the 40 MR will provide useful even if you're against a mostly AD enemy team comp. Generally, there will be magic damage somewhere, usually from Supports and/or Junglers. While it's not a huge amount, reducing it could still save your life. After buying this item, you will never run out of mana again, even without a Blue Buff.


The item offer 300 HP, 50 AP, 15 Magic Penetration, and a unique passive that is very effective when poking down the enemy late game. This item is purchased last after Rylai's is completed, since the Unique passive will not be as effective without the slow from Rylai. Haunting Guise is picked up very early though for the HP, AP and Magic Penetration.


As stated previously, our goal is to stack as much Magic Penetration as possible. This item is perfect and doesn't need a lot of justification.


This is another Core item for AP Corki for numerous reasons. It offers 500 HP, a huge amount, which allows you room for error if you position incorrectly and are taking damage, the HP also allows you to play more aggressively and use Valkyrie for damage if needed. By the end of the game you will have over 2800 Hit Points. The most important aspect of this item is the slow and its synergy with Liandry's Torment.


The reason I list this item last, even though it's not last in the build order, is because it's the most debatable among AP Corki players. I'm personally of the opinion that there is no better item for the slot. Just because Corki doesn't have the best AP ratios doesn't mean it's not beneficial to build AP and have close to 600 by the end of the game. It's very common to fire off and land 3 Rockets in succession, which altogether adds up to 1.05 AP ratio. Valkyrie does 5 ticks of damage for 0.2 AP each, so if the enemy chases you throughout the whole thing (Another semi-common scenario) then that's another 1.0 ratio. Phosphorus Bomb is a 0.5 ratio, not great but not bad either.

Since we're seeking as much Magic Penetration as possible, this item might seem like a worthwhile buy, and even offers defensive stats in the form of MR. This is a bad purchase because the aura of the MR reduction is too short and will only be effective if you're within auto attack range...which you shouldn't be.


This item isn't awful, but the drawback here is that to make full use of it, you need to be within auto attack range. Which again, you shouldn't be. AP Corki is more than capable of putting out huge amounts of damage from a very safe range. Lich Bane does not increase your damage output so much to the point where you need to sacrifice your safety. This item is a trap and baiting you into dying.



120 AP is nothing to sneeze at, but realistically the only item it could replace in the build is Deathcap, which gives even more AP. The CDR is not needed with our build. The Active effect isn't terrible, but has a 750 range so you'll likely have to blow it on the enemy bruisers that are diving your backline. It's not an awful item, but replacing Deathcap with this would lower your AP to 422 with our build. It's preferable to have a higher amount of AP to do more damage to all targets.


While it is a jungle item, quite a few laners have been known to pick it up, and I've seen this item recommended in some AP Corki guides. The AP on this item is very low, and while it offers some decent stats like 10% CDR, Mana Regen, and 20% Spell Vamp, these stats aren't strong late game when you need to blow people up. You do not need sustain like Spell Vamp in the mid and late game, it is only beneficial during the laning phase, and even then, it's nothing amazing.


This item requires you to buy a Tear early on to stack it, which delays your power and weakens your early and mid game. In addition, the shield is not hugely helpful since with proper positioning you shouldn't be in much danger.


If there were a 7th item slot, I would likely be using this item. In very rare instances, I will actually replace Deathcap for an Hourglass. Usually I will only do this when the enemy team has a fed Zed, since he has the mobility and burst to get to you, whereas many other AD's simply can't do that. I am not scared of a fed Riven or Jayce as AP Corki, but a fed Zed is quite terrifying and requires an Hourglass.

Many times I will hold off on choosing my level 1 ability. In general, if the opponent is someone I can harass, I will take Phosphorus Bomb first. On occasion, I will take Valkyrie first if I'm worried about an extremely early gank. Sometimes I will also take Valkyrie first if I think I'm going to be late to lane and miss a CS, I will Valkyrie toward the lane to ensure I don't miss any farm.

I alternate between Phosphorus Bomb and Valkyrie, taking 0 points into Gatling Gun until I am forced to later in the game. Taking one point into Gatling Gun hardly adds any damage during fights, whereas the extra point into Valkyrie adds a similar amount of damage and has the added benefit of lowering it's cooldown by 3 seconds.

This is a video of a game of mine while I was streaming. If I had taken 1 points into Gatling Gun, I would have not gotten this kill on Ahri, and I would have not been able to kill the Master Yi as well. The lower cooldown and extra damage from Valkyrie were critical. As I approach the tower and Ahri flashes, Valkyrie just came off of cooldown. If it were even one rank lower, I wouldn't have had it available and would have had to back off. Likewise, as Master Yi chased me down to try and kill me, if Valkyrie were on a longer cooldown I would have surely died.
Play Video

I consider Flash to be mandatory, because it allows you to use Valkyrie in an offensive fashion. Without Flash, Valkyrie becomes a purely defensive tool, and using it aggressively would result in death more often than not. In the video I posted in the previous section, Flash was critical in making the plays that I did.

vs.
Barrier allows you to live longer, which will allow you more time to get off extra rockets or abiities. I prefer Barrier over Ignite because even in the early game, you can use the 2 second shield to deal more damage with your abilities than Ignite would deal. Late game, a single Rocket or Phosphorus Bomb will deal more damage than Ignite will.


Teleport is in my opinion the only other viable Summoner Spell, and is incredibly strong in solo queue at all elo ranges. Even if the enemy spots your Teleport and begins to retreat, you have Valkyrie to close the gap and long range rockets to finish them off. A good Teleport can completely turn a game around and swing the momentum in your teams favor. If you feel confident foregoing Barrier, pick up Teleport.


Cleanse is situational but definitely worth picking up against certain team compositions. If the enemy has Ashe, Rammus and Ahri, Barrier is not going to save your life if any of their CC lands and gets followed up on.

Pros

• High burst damage at nearly all stages of the game when you hit level 6.
• Virtually ungankable during the laning phase. If you die, it's because you made a mistake and allowed yourself to.
• Extremely good farmer, can't be zoned out and denied farm with Rocket's range.
• Since AP Corki's are fairly rare, there is a surprise factor involved. Many times the enemy will use the wrong runes against you and even buy the wrong starting item (Many mids will buy Cloth + 5 Health Potions versus you)
• A safe blind pick when you're not certain who the enemy mid lane is.
• Has some of the best poke in the game once you have some of your core items. If you want to make your enemy uninstall and hate League of Legends forever, have a Jayce or Nidalee in the top lane for hilarity.

Cons

• Since AP Corki only really has one damaging ability from levels 1 through 5, he is not the most useful if an early team fight breaks out in the jungle at a buff camp.
• Valkyrie can be interrupted by a number of knock-up and CC abilities if you don't time it correctly. You can be hooked mid Valkyrie by Blitzcrank, Thresh, Nautilus...you can be knocked up by Jarvan, Zac, etc. Timing this ability is crucial.

• You must let your team know that you're playing AP Mid lane. If you pick Corki in silence, nearly everyone is going to assuming you're laning bottom as the ADC.
• Starting level 6, you can use a Rocket and Phosphorus Bomb to clear the caster minions.
• Corki has incredible wave clear and can protect a tower under siege rather easily while your team regroups or focuses on objectives elsewhere.
• Check your lane opponent's rune page at www.lolnexus.com, quite often they will run a pure Armor page against you with no Magic Resist. This information is useful and will let you know how much damage you can deal. Alternatively, you can just wait until they show up in the lane and click on them, but it doesn't hurt to know exactly what they're using and it's not like you have anything else to do during the loading screen.
• Starting around level 7, after pushing out your wave, you should Valkyrie over to Wraiths and clear the camp using all of your abilities. Make sure to be close enough to the wall when you Valkyrie so that the burn damage covers the camp and actually hurts the Wraiths. If you do it from too far, the burn damage will not cover the camp.
• Your "Big One" rocket that you fire every three shots, has an increased AoE radius along with increased damage. Quite often your opponents will hide behind minions thinking they're safe, or stay off to the side. Rather than aim for the champion itself, consider aiming for a nearby minion to deal splash damage to the champion.
• In the mid and late game when you have a high amount of CDR and higher level ultimate, you will store rockets fairly quickly. Do not be afraid to spam rockets into the enemy and poke them down before a teamfight breaks out. Be mindful of your supply though, you don't want a fight to break out when you have 0 rockets on hand.
• Try and bait melee enemies into chasing you on your Valkyrie path by letting them get very close to you, almost within auto attack range and then using Valkyrie to get away. Of course be mindful of any CC or gap closers they may have, this strategy isn't always a good idea.
• Phosphorus Bomb reveals the area where you aim it. You can use it at the edge of Dragon and Baron pit to see the creature and it's HP inside.
• Be careful about using Valkyrie aggressively during the laning phase if you do not know the location of the enemy jungler.

I've played AP Corki in both Top and Bottom lane in addition to Middle. It's actually incredibly strong in bottom lane once you hit 6, however, you should only do this if your team has heavy amounts of AD in Middle and Top, like a Zed and Jayce for example. I do not recommend doing this though as it's generally beneficial to have a ranged physical carry. However, AP Corki in top lane is very efficient and a great pick so long as your team does not require a top lane Bruiser.

I am not going to go through every matchup, but I will talk about a few in particular. Corki does not have any problems against champions like Kassadin, Akali, Fizz, Zed who in general are pretty tame 1 through 5, but typically become scary at level 6 when they get their ultimates. Fizz and Zed are very simple to deal with as Corki because when they try to all-in you, you can simply disengage with Valkyrie. It's important to note that against Zed, you don't want to Valkyrie too soon, or he will actually follow you and reappear next to you.


Kassadin is simple to deal with even post 6 because of your rockets. You can use them to either harass him if you think that's viable, or simply use them to farm from max range. Because of your range, Kassadin needs to really overextend to harass you, and it's a long walk back for him during which you will land Phosphorus Bomb and numerous rockets. Kassadin is also not the best at farming under the tower, so your pushing power will make it more difficult for him to farm. Lastly, Kassadin needs to roam, get kills and snowball. This cannot happen if you apply pressure on the lane and keep it constantly pushed, an easy task for Corki.


Zed is easy to deal with in lane, but eventually he will reach a point in time where he's mobile, and has enough items to burst you down. Valkyrie will not save you, and I generally buy a Zhonya's Hourglass in place of a Deathcap while playing against Zed. Nearly every AD carry in the game can be kited or dealt with fairly easily as Corki, but Zed is pretty dangerous and a late game exception.


Fizz is very simple to deal with and much like a Kassadin, to deal damage to you he will have to come within melee range. Unless he plans to all-in you and try to kill you, in which case you can simply Valkyrie away, he will retreat back in which time you return the damage. He will avoid some with Playful/Trickster, but you should be able to return something at least while all of his abilities are on cooldown.


Akali is much like Kassadin, where her 1 through 5 is extremely weak, but when she gets her gap closer she becomes the dominant one in the lane. Treat Akali the same way you would Kassadin, keep your distance and use your Rockets to farm and/or harass her. If you can keep her health bar down she will likely not close the gap on you to deal damage. In the event she does, you can Valkyrie away.


Yorick is one of the few champions in the game who truly beats AP Corki in lane. He has harass, sustain, and more importantly his Ghouls will more often than not get in the way of your rockets, protecting Yorick from your harass. It's not likely he will kill you, but it will cause you to miss CS and will make you regret playing this matchup.


This matchup is all about surviving until you're 6. When you're 6, you will have the upper hand and can harass/farm from safety. You can get out of his ultimate easily if he uses it on you, but this is a difficult matchup 1 through 5 if Jarvan is aggressive, which he should be.


A good Anivia is quite a pain to play against 1 through 5. She out ranges you in a lot of ways and generally out trades you. Once you hit 6, this lane generally just becomes a farm fest.

Thank you for checking out my guide, again, my Summoner Name on the NA server is Ajido. You are more than welcome to add me in game to discuss this guide or any other questions you might have about League. Feel free to leave any comments, suggestions or constructive criticisms below!