This is my first guide guys so don`t be angry if it`s not so good. It`s my way of playing Corki and I did good jobs with this items.

My Marks are full of attack damage because you get massive damage from them. For Seals I take mana regen because corki uses much skills and needs much mana points so mana regen is very important for him.For Glyphs I take magic resist because in early game corki is not so strong against mages with many runes. For Quintessence I take attack damage too because massive damage with corki`s passive at the start is very strong. Alternetive you can take attack damage for Glyphs and Armor pentration for Marks.

For Masteries i made 21/9/0. The most points I added to Offense because armor pentration and extra damage is very nice for corki. The other 9 points i added to Defense because life regen and some extra defense will give corki better life abilities.

First I choose Phosphorus Bomb because in early game that spell makes the most damage. Next I skill Valkyrie bacause it`s important to come forward to your opponents or to fly away if they want to gank you. First you skill up your Phosphorus Bomb an your Gatling Gun because taht 2 spells makes the most damage. The Valkyrie makes not good damage so I skill up that skill very late. Skill your ultimate at lvl 6,11 and 16.

First I buy Dorans Blade because it gives you hp for extra life ability, damage and some life steal. It´s a very nice item for corki at the beginning. Then i buy some Boots of Speed fo extra speed. After that i buy one of the most important items for corki.The Manamune. It gives extra mana and mana regen and nice attack damage. Then comes Berserker`s Greaves for some attack speed. When you have 1 or more tanks in the enemy team, buy The Black Cleaver. When they have no tank, buy Trinity Force. After that you need a Bloodthirster. The lifesteal and the damage is very nice for corki. Now you have to decide wether you want to buy Banshee`s Veil. It`s gives more life chance against mages and gives you the chance to play more agressive.If the enemy tank has much hp, buy Madred`s Bloodrazor. If you don`t buy The Black Cleaver, buy Youmu`s Ghostblade. It´s a nice item with cooldown reduction and armor pentration and makes corki`s skills more usefull.

When you are fighting against an opponent`s champion in a 1o1 then first activate your Gatling gun, because it makes huge damage. Then use your Phosphorus Bomb to make some extra damage. After that you have to fire 1 missile and then you normal attack 1 time. Repeat that every time. With this way you use the passive of Trinity Force very well. Every normal hit will hit the enemies very strong. If one enemy is to strong for you to start a 1 on 1 fight, try to spamm your missiles on him to get his hp lower. Wether he has low hp fly forwar him with Valkyrie and kill him. If you enemies try to gank you fly through walls with Valkyrie. It works at the most walls. Use Valkyrie to follow opponents running away and then attack them again. And ever let at least 1 rocket there for ganking an enemy at tower or attacking other opponent champions.

The best way to play Corki in a team fight is to stay back and attack from distance. Be carefull that your opponents can`t focus you. You can gank enemies when you are playing on mid lane. With your "Valkyrie" you can fly into a battle and hit the enemies hard.

Farming with corki is very easy. If no enemy is there you can spamm your missiles on minions to get much money. Combine the ultimate with your Phosphorus Bomb to kill the mage minions in the back. With your Gatling Gun you can also farm good but never use your Valkyrie to make damage. It doesn`t make much damage it`s only there to come away from enemies or fly forwar to them.

Pro:
-Corki has huge attack damage and he is good to gank enemies out of the grass.
-With his skills he can attack many enemies at once so he is good for farming and for team fights.
-With the right items corki can be one of the bast tank killer.

Cons:
-Corki uses much mana so without mana regen you`ll have to port back very early.
-If an opponent gets near enough to attack, slow or stun you it`ll be hard to get him down or get away.
-When the enemy team focus you in a team fight you are dead early because you can`t take so much damage.

That`s my way of playing corki. Please if you have some advise tell me. :) I guess Corki is a really funny champ because he is difficult to play but he is really strong.