Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
This build is the culmination of my trying out different builds and pulling from each one what I thought was best. If anyone feels that I have copied their build I will try to give them credit. Corki is an amazing character that fills a great niche in game play. He is a GREAT FARMER. Corki can farm better than many characters, outclassed by few. This is his advantage. Knowing how to farm will help corki get better items faster and in the long run get more kills, creating a loop of dominating the other team.
These runes are mostly standard. The armor pen is obvious along with health quints. The armor gained from flat runes is very helpful in the beginning of the game, and along with the items and masteries make corki very durable. Mana can be an issue as well if abilities are used too often, so having mana regen helps a lot early game, but is less useful late game for teamfights.
Getting mostly offense is easy with corki being an ad carry. The defense points help corki in the lane phase to withstand harassment. Staying in the lane and farming longer is all a part of the strategy.
This item build is what really sets this build apart from others. The cloth armor helps with early lane presence again, but by ultimately building into wriggles lantern give corki a huge boost. The lantern gives, armor, sizable lifesteal, and two amazing passives. The free ward is practically an anti gank mechanism. The passive is incredible. With the lifesteal there is a 20% chance to heal over 70 health. Within one wave corki can gain over half his health back, which allows him to farm longer and resist harassment. Plus if you want to grab red or blue buff, the time it takes to kill them is decreased and you don't have to base afterward to heal. Being able to grab red buff on the way back to mid after grabbing new items is amazing, and to do it without losing time in lane is even better.
IE and phantom dancers are basic, but depending on preference and gold sheen can be gotten any time after getting IE and one PD. The attack boost after firing a missile makes this item unfair for corki, allowing him to harrass and attack much more effectively at mid and endgame before a teamfight starts. Building this into TF has obvious benefits, among them a 100% crit chance.
If by some miracle the game isn't over by now you can sell the lantern and boots to buy a bloodthirster and black cleaver. It will give better lifesteal and more damage, as the lantern's passives are less useful at endgame and the boots movement speed boost are covered from the phantom dancers.
Many variations on this build can occur, and buying items in different orders can work depending on how much gold you have at one time. If you have enough to buy sheen outright, then go ahead and do so, but don't buy the mana crystal to later build into sheen. In addition if the enemy team has a lot of ap damage a banshee veil might be more useful to give survivability. As the game moves on it may be more beneficial to sell it and buy one of the items in this build. Selling the boots to buy another item is extremely important to remember as well, because the phantom dancers will give enough ms on their own. The power increase makes corki a tank, able to destroy anyone.
Phosphoru bomb is amazing, nuff said. The blind on it is immensely useful for both laning and teamfights, and helps corki 1v1 even melee dps. Especially at lvl 7 one missile and the bomb can kill all three caster minions. Gatling gun is imperitive for teamfights, and at endgame can outright kill characters. The dmg and armor pen make this ability truly destructive. It is important to always come into teamfights from behind as ranged dps, but as corki it is even more important to ensure gg hits as many champs as possible. The missiles are the biggest part of corki's harass and farming. The missiles can be used to destroy neutral camps, farm minions, and harass. A big key to corki is to wait to go back until lvl 6. It is IMPERATIVE TO TRY AND WAIT UNTIL LVL 6 TO BASE. That way your missile count will rise while your basing and you will return to lane with a nice stock instead of waiting for them to generate. Valkyrie is a simple escape move, but don't be afraid to use it if your confident a gank won't come or to do that extra bit of dmg to get a kill. Corki's passive isn't as noticeable as others, but just adds to the total destruction.
Picking flash and exhaust give corki a strong early game presence to get a kill. If the enemy champ is just eating missiles or harasses and doesn't go back, the combo of using the spells and his abilities make a kill easy to achieve. Watch out for an invite though, if the enemy seems to be inviting the attack it may be a setup for a gank. The reason flash and exhaust are better than another spell like ghost is the simple speed with which an escape or chase can occur. Flash and valkyrie together prevent most ganks, especially with a ward to see a gank coming. In chase or fights exhaust is much more useful than other spells, shutting down a carry until the team can kill them.
Early game should include a combination of farming and harassing. Mid is very easy to control against certain champions, and another guide features the effectiveness of corki against other mid champs. Laning strategy should go as follows: last hit/farm > harass > kill. A great strategy is to wait until the back row of minions have low health. When the enemy gets near them, lay down a bomb. It will damage them and kill the minions, and if they try to attack you the blind will help. Try not to get the kill too often because it invites a gank, and watch out for them having flash or ignite.
Never be afraid to pop a potion, but don't do so as soon as you are missing 200 health. If you always have full health the enemy won't think they can kill you and will be more cautious. Having a small fight that you valkyrie out of and heal up from while they lose health is beneficial. If a fight starts immediately pop the mana potion, corki can chew through his mana very quickly, and saving the potion for a fight is necessary as another edge the enemy might forget about. If you are getting pushed really hard it may be necessary to use abilities to clear out a wave, and then the potion might be necessary also.
Gameplay changes after corki hits lvl 6 and has wriggles and boots. Now he can get either buff easily, and can solo dragon, thats right, at lvl 6 with two items corki can SOLO DRAGON. Full health is a must obviously, but by spamming all of his abilities repeatedly along with the lifesteal and passive corki can solo dragon. It is a lot easier with either buff, but using gg is a must and as more points get put into his E it becomes easier. Along with the ward corki can safely kill dragon and get away if somebody comes to try and take it from him. In the lane missiles should constantly be spammed and lanes pushed. If you push a lane either kil the tower or move to another lane, attacking neutral camps along with way until the minion wave moves back towards your tower. Farming is EASY at this point, and there is no excuse to not have more than 50 minion kills more than other people on your team, if not more.
Endgame is mostly the same, farming and pushing lanes, going back whenever you have enough to get another major item. Corki can solo almost any champion with exhaust and his abilities, but be careful and do not hesitate to leave as soon as the fight seems unable to be won. Between flash and W Corki should be able to escape almost any character chasing him. Tagging along with a character who has a stun makes a deadly combo as corki can easily destroy a character's health during the stun, even tanks do to his large armor pen from E, runes, and/or a black cleaver.
Corki is a very difficult champion to master. He requires a lot of practice and experience with farming using his abilities. A careful balance is necessary to know when to make a risky move and when to play back and farm. Early game kills can easily be deaths, requiring careful planning and execution. Items are very important and knowing how to control neutral monsters in both jungles as well as pushing lanes. Corki is a great champion and works well in many teams, filling a hard carry role to make it a gg if fed.