Thought I'd write a little(overly comprehensive) guide on my favorite and most played hero, Corki the Daring Bombardier. I've got over 350 corki games under my belt now (handle h3w0), and have tried just about every build/rune/mastery combination under the sun, and I swear to any/all deity's that if I see another trinity force build I'm going to cry. If anybody wants to see the build in action feel free to add me up and play a game. I used to play a lot of competitve dota (over 4 years) and my favorite hero for a long time was Puck, who I believe corki is the closest LOL counterpart to. Blink and spell domination? yes please.
As a preface, I'm not completely hating on atk dps corki. It works alright I guess, but it doesn't feel nearly as competitive or aggressive as pure AP. AP plays VERY differently from atk corki. As far as play styles go, ATK corki is a farmer/late game carry, and AP corki is an unstoppable engine of gank, rocketing his foes with impunity. So here is the build to shock and awe your opponents with lethal salvos. Between the many times I've played both builds though, AP always ends up carrying a lot better than ATK. If you want to do insane damage from 1000range while having a tanks hp, this build is for you.
This guide is intended for solo mid corki, and I haven't tried this build at all in the lane with somebody else. Corki flies solo, get it?
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Viable Summoner Spells
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1. Flash: Always take flash. It is not an option, but a requirement. This is not debatable. The amount of extra kills it will net you and times it will save you make it too valuable to miss. Also the only way to save yourself from a flash heavy team is to have flash yourself anyways, so get used to it.
2. Teleport: I always take tp as my second, for a few reasons. First off, if you are solo, it is necessary to keep your exp/farm up early on. Most importantly in the first 10 minutes, you'll use it for a free mana refill/buy with no time out of the lane. After that, it becomes a great asset in teleport ganking other people. Just wait for a figth to start then tp on the most oppurtune creep. Most people tend to get tunnel vision when they go after kills and dont see the tp swirls, assuring you kills.
An added note on tp, VERY few people abuse tp'ing to wards/mushrooms/jack in boxes etc. Dropping well placed wards in their jungle/sneaky places will net you some ninja tp kills.
3. Exhaust: Some people like it, I'm not a fan of it on corki, but I won't hate on a flash/exhaust build. He really doesn't need it for chasing with flash and valkyrie though, the magic resistance reduction is nice however. I don't feel like it is better than the huge creep waves/kills you get from TP though.
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Mastery
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I used to go 21/9/0 corki for 5pct damage and dodge/nimbleness, but more often I've found myself going 9/0/21 for just the spell penetration and imp tp/flash and cd reductions, as well as all the other nifty perks. Those are the two mastery specs I would recommend.
If you don't have the full 30 points, go for the archaic knowledge in offense first, as it is your most important benefit. 9/0/21 only feels good if you have 30pts, and short of that I'd just fill out as much of offense as you can.
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Runes
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My personal rune build is a little eclectic, but I feel it works.
Reds: Magic penetration all the way. Mag pen is the best ap dps stat atm. There is no reason to get ap runes at all.
Yellows/Quints: Dodge. Going out the gate with 11pct dodge is very nice, and has saved me from innumerable deaths while hearing somebody on the other team in all chat scream 'lucky dodge' with profanity laced in. This is an early game benefit more than anything, but it is very nice for survivability in the 1v1 lane setting. Too bad those snowdown showdown dodge runes aren't around anymore.
Blues: I have +base mana (the @level 1 ones, not at 18). 110 mana out the gate is nice imo. gives you an extra phosphorous bomb and a half, and as AP corki you are here to spam your spells.
A full sheet of magic pen would be nice too, I'll probably get around to one of those sooner or later. I feel the dodge/+mana really adds to your ability to stay in the lane early on though.
2/13 edit: I've started a forbidden romance with HP@18 yellow runes and base HP quints. I didn't like the idea at first, but SO many other people (specifically solos) have hp runes it can be hard to deal with unless you have some yourself. My current runes are RED MPEN/YELLOW HP@18/BLUE BASE MANA and +32hp quints.
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Spells
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Before explaining, here is how you level them.
1.Phos Bomb
2. Valk
3. Phos Bomb
4. Gatling
5. Phos Bomb
6. Rocket.
7. Phos Bomb
8. Gatling
etc
Phosphorous Bomb: [CD 8 second//90 base mana cost with +10mana cost per level]
It has a targetable range of 600, and an aoe of what I believe is 325. This is your main damage source early on. Dealing 80/130/180/230/280 damage, as well as having a 35pct mis debuff and reveal stealth benefit. This spell has so much utility it makes shaco bluff. It has a .5ap modifier.
Valkyrie: [CD 20seconds//100 mana cost]
While it isn't as far as it used to be (only 700 max range now) it is still amazing for leaping walls and terrain, or just putting distance between yourself and others. Most people only use valk for escaping, but it can be used very well offensively, as it does deceptively high damage over time. You will die countless times however after using valkyrie to try and kill someone only to not have it for your escape, so play it safe and smart. It does 60/90/120/150/180 damage per second with a .4ap modifier. It will still be your lowest dps source throughout the game regardless of its potential, and is mostly used for its leap mechanism.
Gatling: [CD 16 second//60 base mana cost with +15 cost per level]
As AP corki this wont do too much damage. It is still very nice for its armor reduction though, as that will greatly help your teammates. Spraying this all over the other team is a top priority to help your teams dps, as well as your own. It is also the extra boost you need to kill somebody alone many times. Once you get rylais, gatling gun should be renamed to 'Death Trap', because a persistant slow/armor reduction is savage. It lasts 3/3.5/4/4.5/5 seconds, reducing 1 pt or armor per level per second. It has 600 range, in a frontal cone.
Rockets: [No CD but limited ammo/25 mana cost +5 cost per level]
You get one rocket every 14 seconds, to a maximum of 7. Every 4th rocket is a double damage world ending patriot missile. They deal 125/200/275 damage. Rockets are the main stay of AP corki. While many scoff at their measly .3ap benefit ratio, the real beauty is that you can potentially unload 5-6 on someone within just a few seconds. They can be very difficult to aim with their miniscule hitbox. The trick is, just stay calm. Many people freak out (especially on seeing a low hp enemy) and unload all their rockets in a hectic frenzy trying to hit somebody. You are VERY crippled when out of rocket ammo. You need to conserve ammo, and pick your shots. Don't panic and click everywhere, stay calm, focused, look about .5seconds-1second ahead of them, and aim. When alone (in jungle or river or without creeps in lane) they can be very hard to hit someone with from afar if they are consciously trying to dodge it. It really isn't too hard o dodge and weave. The real beauty is the range though, as well as shooting over terrain. It is usually good to aim with the blast radius in mind, aiming to hit a creep close to somebody instead of trying to hit the moving player. Rocket aiming tends to make or break AP corki. When you first hit 6 its usually good to save up at least 3-4 rockets before using them, so you can create some burst at least. A lot of your kills later on will be from finishing people off with 2-3 rocket shots. Generally, if you only have 1 or 2 rockets, don't even fire them unless its a desperate situation. Your burst is heavily reliant upon your rocket management.
Passive: Hex-Tech Shells
Your base attack does an additional 10pct true damage. Very nice for harassing early on. Many people use this and gatling as the justification of ATK corki, but 1 atk ability and 1 atk passive vs 3 spammable ap spells seems like an obvious choice to me.
I don't max valk till last. It can be nice to max earlier for its damage, but most of the time it will be used for escaping, and valking over a group of ppl is a death sentence without flash to get you out afterward.
If you feel that you are a candidate for getting level 1 ganked, take valk first just so you will be safe. If you have valk and flash at level 1 you pretty much have to let them kill you.
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Items
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Go out the gate with a Sapphire Gem (400g) and 2 health potions (35gx2)
1.Your first item and main priority is turning that sapphire into a catalyst. The catalyst will keep you in the lane, and give you a very nice buffer of hp. It costs 925g to create catalyst from the sapphire. I almost always return to get the catalyst as soon as its viable. If you have tp up, a base buy and tp back out with catalyst is preferred. You want to get this thing on you as early as possible.
2. Boots (350g) which you will turn into sorc boots(another 750g). Gotta love that magic penetration. If your lane is going very well early on, it can be worth waiting to have ~1275g to buy catalyst and boots, since the added maneuverability is very helpful, especially against most other solo champs who seem to have ability's that require dodging.
3. This is where you make a judgment call on how good you are doing. If your farm is good, and you feel like you will be ganking, get a soulstealer (1225g) asap and start farming those charges. At least 9/10 games I end up getting the soulstealer, but some games that are very low death, or if your team isn't being the gankers, its not worth the gold. My rule of thumb is, if you don't see yourself able to hold at least 7 charges on your soulstealer, it is not worth buying. If your farm is total **** and you've died though, It might not be viable. Buying this thing passed around the 22-24 minute mark can be a risky investment, as you are crippling the rest of yoru item development.
4. Rylais (3142g) This is where the fun really starts, and corki becomes a killing machine. If soulstealer didn't happen you just go to rylais after your boots. When building rylais I always buy the belt of giant first for the huge hp buff. Rylais on corki is very dangerous due to all the spell spam he has. Phosphorous bomb becomes an aoe slow, gatling becomes a persistent cone slow, valk slows over targets, and rockets slow (which makes subsequent rockets VERY easy to hit with). In short, just about nobody save for a few champs will be able to escape from you. I love this item. The stats are great, the build up items to it are great, and the item effect is amazing.
5. Time for another judgment call. You're probably around level 18 by now unless you have been mercilessly killing people left and right, so its time to do something with that catalyst. I almost always turn catalyst into a Banshee Veil (another 1390g). If you are doing as good as you should be at this point, the other team may have caught on you should be a focus target (especially with soulstealer charges). I very very very rarely turn catalyst into a rod of ages (1710g) unless they really have NO disables and are all atk dps (very very rare, and in which case you've probably already won anyways). You need the magic resist at this point to keep enemy AP chars from unloading on you, and the spell absorption will save you countless times.
6. Void Staff.(1885g) This item is much cheaper than it used to be, and much more viable. However, if the other team isn't respecting your damage and not buying magic resist, feel free to skip straight to zhonyas for extra firepower.
7. Zhonyas.(3620g) Most games don't last this long, but hey, somethings got to go in that last slot right? Pretty self explanatory item.
In summary, the usual build is
Catalyst->Sorc Boots->Soulstealer->Rylais->(Rod of Ages or Banshee Veil)->Void Staff-> Zhonyas.
If they never get around to getting much magic resist it can be a good idea to substitute in a Lich's Bane instead of a Void Staff for your last slot, but I don't find myself doing this often.
Every game is different, and sometimes you may have to change your build some for your opponents. Generally speaking, in an average game, you should have catalyst/sorc boots/soulstealer around 15-18 minutes. Finishing rylais somewhere aroudn 25 minutes is very powerful. If you pull out the rylais pre or @ 20 mins, they probably already plan on surrendering in 5minutes.
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The Early Lane
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Corki might be one of the best solo mids in the game. Very few champs can hang in there with him when he gets going. Tristana/sivir/ashe/teemo are all very favorable matchups for corki. Corki tears through other dps'ers. A good tf can make you work for it sometimes. Chogath/udyr can be hard to burst through but its doable if you pace your spells. Heimer can be annoying, but when isn't that the case.
Here are some nice rules to abide by early on, and they are prioritized from 1 downward.
1. Dont Die. This is your main priority always in LOL. Very few instances is something worth dying for. Especially with you as the carry and a soulstealer, not dying is your main focus.
2. Don't let your opponent outfarm you. Hit tab to check creep scores often. I'm of the opinion that its unacceptable for just about any hero to outcreep corki in the lane (except maybe turret heimer). If they have more creep kills, you need to turn up the juice and make them fear coming in close. Time your harasses to when they would be last hitting one of your creeps.
3. Farm. Get those last hits. Don't auto attack it over pushes your lane and makes you look bad (because you probably are bad).
4. Try and kill them. It may seem silly to put killing your opponent at the bottom of the list, but if you are dying/getting out farmed in the process of trying to put hurt on them, its not worth it. If you aren't able to secure a kill, all you are doing is wasting time and mana while they outcreep you. If you are against a very solid player they probably wont die to you 1v1(nobody should die 1v1), so just outfarm them.
Corki has one of the best last hits in the game, and can easily get most every creep in a wave if you just time it instead of auto attacking. Don't auto attack creeps early on by the way, it makes you look bad.
As far as fighting against your lane opponent, there is a general rule for 1v1 engagements. They won't die unless they give you the kill. That's not to say most people wont be willing to let you kill them. Being killable usually means they are being offensive and trying to hurt you, but that's the main way people expose themselves early on. If you can tell your lane opponent is a very cautious player who is just there to creep, dont be overly aggressive and let yourself get hurt needlessly trying to harass them. If they want to creep, then fine, because few champs can out creep corki. Just make it your commitment to pepper them away from the wave and outcreep them.
Pre-level 3 you are very weak. I only use 2, maybe 3 phospho bombs before level 3, cause it doesn't hurt too bad at rank one and you want to save your mana for higher ranks. Don't not use it at all though, that wastes mana regen and the extra mana you get on level ups. When you wait to spam until level 3 or 5, it can also make your opponent think you are a more passive player than you really are, making your damage explosion all the more surprising.
Once you hit 3 its time to turn the heat up with your newly painful phospho bomb. As a rule, save your valk for escaping (never know when someone is waiting to see you use your escape so they can come out of bush) and only use gatling gun when its going to be a kill. Otherwise, your mana is only for phospho bomb. It has decent range and is fairly easy to target.
One of the main ways you will get an early kill against your lane opponent is Flash-> phos bomb very quickly together. If you have someone low but they don't want to return yet, they will try to dance outside of phospho bomb range and soak up exp. If you are quick, even an opponent who has flash themselves probably wont have time to pull it off, since phosphorous bomb is instant. It is even fairly easy to tower dive at level 4-5 for a kill with flash in and valk out. Always save the valk for the exit, since it is much slower and they have more time to react if they see you valking in instead of a flash.
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Somewhere around 15 minutes
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WHY AREN'T YOU GANKING PEOPLE YET. With two blink mechanisms and tons of firepower, everybody but pure tanks will be crumbling to your solo items/exp, unless they got fed by noob teammates. I'm a big fan of wards. Placing a few in river (by dragon etc) will save you and create many gank opportunity's. The longer the game goes on the more it becomes a team effort, but by solo'ing mid you've committed yourself to carrying your team. You need to be the impetus behind most of your teams ganks. As soon as I get my rank1 boots on though, I try to be all over the map. Watch the minimap religiously. When you see someone with gankable hp, head there as sneakily, but quickly as possible. Don't let your lane opponent see you walking top, they will probably give their buds a heads up. Wait until you are out of sight of creeps/champs.
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Tough Opponents to Lane Against
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Good twisted fate: I say good, because a bad twisted fate will feed you with their very fragile and slow hero. A good twisted fate will sit back and spam wildcards while staying out of your range. He can be hard to kill if he doesn't want to come in engagement range, and you always need to watch out for a gold card gank with the assistance of another lane. However, it isn't hard to wildly outfarm a tf though, so while you may not be killing him you will get your share of creeps. Gotta watch out for a gate or destiny/gate back to the lane after he heals as well. YOUR REWORK WILL COME SOON MARK MY WORDS WENCH.
Heimerdinger: Kinda obvious, but he is the easiest solo hero in the game. Even with 0 last hit skill he can creep with the best of him just by his turrets, all the while staying VERY far out of your range and spamming rockets (they hurt btw). Heimer is nigh impossible to kill alone due to the distance he plays with. He only dies if he wants to get close enough to be hit by you, which a good heimer wont. Against heimer, you just need to be committed to keep up with his farm. Once you get rockets, save up a small barrage of 3-4 so you can phos bomb and rocket a cluster of turrets down quickly if he is getting too set up in the lane. Give him nothing. Take from him everything. EDIT: his rocket range has been nerfed since I wrote this, but he is still a pretty strong solo. He just maybe might have to get sort of close to you to rocket now.
Good Cho'gath: With hes life regaining powers and tank hp, it can be hard to dent him. I recommend conserving your mana until 4 or 5 before you really turn up the heat. Against chogath its all burst. Don't just lightly harass him over time like other champs cause he will heal it back. Pick your spot and unload. He's only rough if you let him regen off of creeps.
Udyr: EDITED: HAHA NERF WHERE IS YOUR TURTLE SHELL NOW. (edited)
Katarina: EDITED: They nerfed kat into oblivion, prob wont see this one anymore, even though her early game is pretty much intact
Fiddlesticks: Can't bee too aggressive with this one. With his disables and drain you wont be killing them early on unless they are reckless, so creeping is the goal. If you are playing cautious good fiddles will realize you are not a kill and will try and take their ulti elsewhere when they hit 6, so don't forget to call missing for your team.
Nidalee: a 30mana heal on spam cd. No nidalee worth their salt will be dying to you in the 1v1 phase. Your goal in this lane is to get as many creeps as you can (wont be too hard since nidalee's never harass) while trying to keep nidalees auto attack farm in check. Both of you will probably be getting a fair share of creep kills, but I feel corki is much stronger early on than an equally farmed nidalee.
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I can't really think of anything else to add at this point, which means I guess I'm done. If anybody has any more questions I'll answer them the best I can. Feel free to add me for a game if you want to see the build in action. Thanks for the read, and remember, stop the unwarranted hate on AP corki!
Edit: Changed a few things to reflect some of the patches that have come out. Guide is current again.
As a preface, I'm not completely hating on atk dps corki. It works alright I guess, but it doesn't feel nearly as competitive or aggressive as pure AP. AP plays VERY differently from atk corki. As far as play styles go, ATK corki is a farmer/late game carry, and AP corki is an unstoppable engine of gank, rocketing his foes with impunity. So here is the build to shock and awe your opponents with lethal salvos. Between the many times I've played both builds though, AP always ends up carrying a lot better than ATK. If you want to do insane damage from 1000range while having a tanks hp, this build is for you.
This guide is intended for solo mid corki, and I haven't tried this build at all in the lane with somebody else. Corki flies solo, get it?
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Viable Summoner Spells
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1. Flash: Always take flash. It is not an option, but a requirement. This is not debatable. The amount of extra kills it will net you and times it will save you make it too valuable to miss. Also the only way to save yourself from a flash heavy team is to have flash yourself anyways, so get used to it.
2. Teleport: I always take tp as my second, for a few reasons. First off, if you are solo, it is necessary to keep your exp/farm up early on. Most importantly in the first 10 minutes, you'll use it for a free mana refill/buy with no time out of the lane. After that, it becomes a great asset in teleport ganking other people. Just wait for a figth to start then tp on the most oppurtune creep. Most people tend to get tunnel vision when they go after kills and dont see the tp swirls, assuring you kills.
An added note on tp, VERY few people abuse tp'ing to wards/mushrooms/jack in boxes etc. Dropping well placed wards in their jungle/sneaky places will net you some ninja tp kills.
3. Exhaust: Some people like it, I'm not a fan of it on corki, but I won't hate on a flash/exhaust build. He really doesn't need it for chasing with flash and valkyrie though, the magic resistance reduction is nice however. I don't feel like it is better than the huge creep waves/kills you get from TP though.
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Mastery
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I used to go 21/9/0 corki for 5pct damage and dodge/nimbleness, but more often I've found myself going 9/0/21 for just the spell penetration and imp tp/flash and cd reductions, as well as all the other nifty perks. Those are the two mastery specs I would recommend.
If you don't have the full 30 points, go for the archaic knowledge in offense first, as it is your most important benefit. 9/0/21 only feels good if you have 30pts, and short of that I'd just fill out as much of offense as you can.
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Runes
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My personal rune build is a little eclectic, but I feel it works.
Reds: Magic penetration all the way. Mag pen is the best ap dps stat atm. There is no reason to get ap runes at all.
Yellows/Quints: Dodge. Going out the gate with 11pct dodge is very nice, and has saved me from innumerable deaths while hearing somebody on the other team in all chat scream 'lucky dodge' with profanity laced in. This is an early game benefit more than anything, but it is very nice for survivability in the 1v1 lane setting. Too bad those snowdown showdown dodge runes aren't around anymore.
Blues: I have +base mana (the @level 1 ones, not at 18). 110 mana out the gate is nice imo. gives you an extra phosphorous bomb and a half, and as AP corki you are here to spam your spells.
A full sheet of magic pen would be nice too, I'll probably get around to one of those sooner or later. I feel the dodge/+mana really adds to your ability to stay in the lane early on though.
2/13 edit: I've started a forbidden romance with HP@18 yellow runes and base HP quints. I didn't like the idea at first, but SO many other people (specifically solos) have hp runes it can be hard to deal with unless you have some yourself. My current runes are RED MPEN/YELLOW HP@18/BLUE BASE MANA and +32hp quints.
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Spells
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Before explaining, here is how you level them.
1.Phos Bomb
2. Valk
3. Phos Bomb
4. Gatling
5. Phos Bomb
6. Rocket.
7. Phos Bomb
8. Gatling
etc
Phosphorous Bomb: [CD 8 second//90 base mana cost with +10mana cost per level]
It has a targetable range of 600, and an aoe of what I believe is 325. This is your main damage source early on. Dealing 80/130/180/230/280 damage, as well as having a 35pct mis debuff and reveal stealth benefit. This spell has so much utility it makes shaco bluff. It has a .5ap modifier.
Valkyrie: [CD 20seconds//100 mana cost]
While it isn't as far as it used to be (only 700 max range now) it is still amazing for leaping walls and terrain, or just putting distance between yourself and others. Most people only use valk for escaping, but it can be used very well offensively, as it does deceptively high damage over time. You will die countless times however after using valkyrie to try and kill someone only to not have it for your escape, so play it safe and smart. It does 60/90/120/150/180 damage per second with a .4ap modifier. It will still be your lowest dps source throughout the game regardless of its potential, and is mostly used for its leap mechanism.
Gatling: [CD 16 second//60 base mana cost with +15 cost per level]
As AP corki this wont do too much damage. It is still very nice for its armor reduction though, as that will greatly help your teammates. Spraying this all over the other team is a top priority to help your teams dps, as well as your own. It is also the extra boost you need to kill somebody alone many times. Once you get rylais, gatling gun should be renamed to 'Death Trap', because a persistant slow/armor reduction is savage. It lasts 3/3.5/4/4.5/5 seconds, reducing 1 pt or armor per level per second. It has 600 range, in a frontal cone.
Rockets: [No CD but limited ammo/25 mana cost +5 cost per level]
You get one rocket every 14 seconds, to a maximum of 7. Every 4th rocket is a double damage world ending patriot missile. They deal 125/200/275 damage. Rockets are the main stay of AP corki. While many scoff at their measly .3ap benefit ratio, the real beauty is that you can potentially unload 5-6 on someone within just a few seconds. They can be very difficult to aim with their miniscule hitbox. The trick is, just stay calm. Many people freak out (especially on seeing a low hp enemy) and unload all their rockets in a hectic frenzy trying to hit somebody. You are VERY crippled when out of rocket ammo. You need to conserve ammo, and pick your shots. Don't panic and click everywhere, stay calm, focused, look about .5seconds-1second ahead of them, and aim. When alone (in jungle or river or without creeps in lane) they can be very hard to hit someone with from afar if they are consciously trying to dodge it. It really isn't too hard o dodge and weave. The real beauty is the range though, as well as shooting over terrain. It is usually good to aim with the blast radius in mind, aiming to hit a creep close to somebody instead of trying to hit the moving player. Rocket aiming tends to make or break AP corki. When you first hit 6 its usually good to save up at least 3-4 rockets before using them, so you can create some burst at least. A lot of your kills later on will be from finishing people off with 2-3 rocket shots. Generally, if you only have 1 or 2 rockets, don't even fire them unless its a desperate situation. Your burst is heavily reliant upon your rocket management.
Passive: Hex-Tech Shells
Your base attack does an additional 10pct true damage. Very nice for harassing early on. Many people use this and gatling as the justification of ATK corki, but 1 atk ability and 1 atk passive vs 3 spammable ap spells seems like an obvious choice to me.
I don't max valk till last. It can be nice to max earlier for its damage, but most of the time it will be used for escaping, and valking over a group of ppl is a death sentence without flash to get you out afterward.
If you feel that you are a candidate for getting level 1 ganked, take valk first just so you will be safe. If you have valk and flash at level 1 you pretty much have to let them kill you.
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Items
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Go out the gate with a Sapphire Gem (400g) and 2 health potions (35gx2)
1.Your first item and main priority is turning that sapphire into a catalyst. The catalyst will keep you in the lane, and give you a very nice buffer of hp. It costs 925g to create catalyst from the sapphire. I almost always return to get the catalyst as soon as its viable. If you have tp up, a base buy and tp back out with catalyst is preferred. You want to get this thing on you as early as possible.
2. Boots (350g) which you will turn into sorc boots(another 750g). Gotta love that magic penetration. If your lane is going very well early on, it can be worth waiting to have ~1275g to buy catalyst and boots, since the added maneuverability is very helpful, especially against most other solo champs who seem to have ability's that require dodging.
3. This is where you make a judgment call on how good you are doing. If your farm is good, and you feel like you will be ganking, get a soulstealer (1225g) asap and start farming those charges. At least 9/10 games I end up getting the soulstealer, but some games that are very low death, or if your team isn't being the gankers, its not worth the gold. My rule of thumb is, if you don't see yourself able to hold at least 7 charges on your soulstealer, it is not worth buying. If your farm is total **** and you've died though, It might not be viable. Buying this thing passed around the 22-24 minute mark can be a risky investment, as you are crippling the rest of yoru item development.
4. Rylais (3142g) This is where the fun really starts, and corki becomes a killing machine. If soulstealer didn't happen you just go to rylais after your boots. When building rylais I always buy the belt of giant first for the huge hp buff. Rylais on corki is very dangerous due to all the spell spam he has. Phosphorous bomb becomes an aoe slow, gatling becomes a persistent cone slow, valk slows over targets, and rockets slow (which makes subsequent rockets VERY easy to hit with). In short, just about nobody save for a few champs will be able to escape from you. I love this item. The stats are great, the build up items to it are great, and the item effect is amazing.
5. Time for another judgment call. You're probably around level 18 by now unless you have been mercilessly killing people left and right, so its time to do something with that catalyst. I almost always turn catalyst into a Banshee Veil (another 1390g). If you are doing as good as you should be at this point, the other team may have caught on you should be a focus target (especially with soulstealer charges). I very very very rarely turn catalyst into a rod of ages (1710g) unless they really have NO disables and are all atk dps (very very rare, and in which case you've probably already won anyways). You need the magic resist at this point to keep enemy AP chars from unloading on you, and the spell absorption will save you countless times.
6. Void Staff.(1885g) This item is much cheaper than it used to be, and much more viable. However, if the other team isn't respecting your damage and not buying magic resist, feel free to skip straight to zhonyas for extra firepower.
7. Zhonyas.(3620g) Most games don't last this long, but hey, somethings got to go in that last slot right? Pretty self explanatory item.
In summary, the usual build is
Catalyst->Sorc Boots->Soulstealer->Rylais->(Rod of Ages or Banshee Veil)->Void Staff-> Zhonyas.
If they never get around to getting much magic resist it can be a good idea to substitute in a Lich's Bane instead of a Void Staff for your last slot, but I don't find myself doing this often.
Every game is different, and sometimes you may have to change your build some for your opponents. Generally speaking, in an average game, you should have catalyst/sorc boots/soulstealer around 15-18 minutes. Finishing rylais somewhere aroudn 25 minutes is very powerful. If you pull out the rylais pre or @ 20 mins, they probably already plan on surrendering in 5minutes.
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The Early Lane
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Corki might be one of the best solo mids in the game. Very few champs can hang in there with him when he gets going. Tristana/sivir/ashe/teemo are all very favorable matchups for corki. Corki tears through other dps'ers. A good tf can make you work for it sometimes. Chogath/udyr can be hard to burst through but its doable if you pace your spells. Heimer can be annoying, but when isn't that the case.
Here are some nice rules to abide by early on, and they are prioritized from 1 downward.
1. Dont Die. This is your main priority always in LOL. Very few instances is something worth dying for. Especially with you as the carry and a soulstealer, not dying is your main focus.
2. Don't let your opponent outfarm you. Hit tab to check creep scores often. I'm of the opinion that its unacceptable for just about any hero to outcreep corki in the lane (except maybe turret heimer). If they have more creep kills, you need to turn up the juice and make them fear coming in close. Time your harasses to when they would be last hitting one of your creeps.
3. Farm. Get those last hits. Don't auto attack it over pushes your lane and makes you look bad (because you probably are bad).
4. Try and kill them. It may seem silly to put killing your opponent at the bottom of the list, but if you are dying/getting out farmed in the process of trying to put hurt on them, its not worth it. If you aren't able to secure a kill, all you are doing is wasting time and mana while they outcreep you. If you are against a very solid player they probably wont die to you 1v1(nobody should die 1v1), so just outfarm them.
Corki has one of the best last hits in the game, and can easily get most every creep in a wave if you just time it instead of auto attacking. Don't auto attack creeps early on by the way, it makes you look bad.
As far as fighting against your lane opponent, there is a general rule for 1v1 engagements. They won't die unless they give you the kill. That's not to say most people wont be willing to let you kill them. Being killable usually means they are being offensive and trying to hurt you, but that's the main way people expose themselves early on. If you can tell your lane opponent is a very cautious player who is just there to creep, dont be overly aggressive and let yourself get hurt needlessly trying to harass them. If they want to creep, then fine, because few champs can out creep corki. Just make it your commitment to pepper them away from the wave and outcreep them.
Pre-level 3 you are very weak. I only use 2, maybe 3 phospho bombs before level 3, cause it doesn't hurt too bad at rank one and you want to save your mana for higher ranks. Don't not use it at all though, that wastes mana regen and the extra mana you get on level ups. When you wait to spam until level 3 or 5, it can also make your opponent think you are a more passive player than you really are, making your damage explosion all the more surprising.
Once you hit 3 its time to turn the heat up with your newly painful phospho bomb. As a rule, save your valk for escaping (never know when someone is waiting to see you use your escape so they can come out of bush) and only use gatling gun when its going to be a kill. Otherwise, your mana is only for phospho bomb. It has decent range and is fairly easy to target.
One of the main ways you will get an early kill against your lane opponent is Flash-> phos bomb very quickly together. If you have someone low but they don't want to return yet, they will try to dance outside of phospho bomb range and soak up exp. If you are quick, even an opponent who has flash themselves probably wont have time to pull it off, since phosphorous bomb is instant. It is even fairly easy to tower dive at level 4-5 for a kill with flash in and valk out. Always save the valk for the exit, since it is much slower and they have more time to react if they see you valking in instead of a flash.
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Somewhere around 15 minutes
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WHY AREN'T YOU GANKING PEOPLE YET. With two blink mechanisms and tons of firepower, everybody but pure tanks will be crumbling to your solo items/exp, unless they got fed by noob teammates. I'm a big fan of wards. Placing a few in river (by dragon etc) will save you and create many gank opportunity's. The longer the game goes on the more it becomes a team effort, but by solo'ing mid you've committed yourself to carrying your team. You need to be the impetus behind most of your teams ganks. As soon as I get my rank1 boots on though, I try to be all over the map. Watch the minimap religiously. When you see someone with gankable hp, head there as sneakily, but quickly as possible. Don't let your lane opponent see you walking top, they will probably give their buds a heads up. Wait until you are out of sight of creeps/champs.
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Tough Opponents to Lane Against
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Good twisted fate: I say good, because a bad twisted fate will feed you with their very fragile and slow hero. A good twisted fate will sit back and spam wildcards while staying out of your range. He can be hard to kill if he doesn't want to come in engagement range, and you always need to watch out for a gold card gank with the assistance of another lane. However, it isn't hard to wildly outfarm a tf though, so while you may not be killing him you will get your share of creeps. Gotta watch out for a gate or destiny/gate back to the lane after he heals as well. YOUR REWORK WILL COME SOON MARK MY WORDS WENCH.
Heimerdinger: Kinda obvious, but he is the easiest solo hero in the game. Even with 0 last hit skill he can creep with the best of him just by his turrets, all the while staying VERY far out of your range and spamming rockets (they hurt btw). Heimer is nigh impossible to kill alone due to the distance he plays with. He only dies if he wants to get close enough to be hit by you, which a good heimer wont. Against heimer, you just need to be committed to keep up with his farm. Once you get rockets, save up a small barrage of 3-4 so you can phos bomb and rocket a cluster of turrets down quickly if he is getting too set up in the lane. Give him nothing. Take from him everything. EDIT: his rocket range has been nerfed since I wrote this, but he is still a pretty strong solo. He just maybe might have to get sort of close to you to rocket now.
Good Cho'gath: With hes life regaining powers and tank hp, it can be hard to dent him. I recommend conserving your mana until 4 or 5 before you really turn up the heat. Against chogath its all burst. Don't just lightly harass him over time like other champs cause he will heal it back. Pick your spot and unload. He's only rough if you let him regen off of creeps.
Udyr: EDITED: HAHA NERF WHERE IS YOUR TURTLE SHELL NOW. (edited)
Katarina: EDITED: They nerfed kat into oblivion, prob wont see this one anymore, even though her early game is pretty much intact
Fiddlesticks: Can't bee too aggressive with this one. With his disables and drain you wont be killing them early on unless they are reckless, so creeping is the goal. If you are playing cautious good fiddles will realize you are not a kill and will try and take their ulti elsewhere when they hit 6, so don't forget to call missing for your team.
Nidalee: a 30mana heal on spam cd. No nidalee worth their salt will be dying to you in the 1v1 phase. Your goal in this lane is to get as many creeps as you can (wont be too hard since nidalee's never harass) while trying to keep nidalees auto attack farm in check. Both of you will probably be getting a fair share of creep kills, but I feel corki is much stronger early on than an equally farmed nidalee.
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I can't really think of anything else to add at this point, which means I guess I'm done. If anybody has any more questions I'll answer them the best I can. Feel free to add me for a game if you want to see the build in action. Thanks for the read, and remember, stop the unwarranted hate on AP corki!
Edit: Changed a few things to reflect some of the patches that have come out. Guide is current again.
