Hello, this is my guide to Ezreal using Ability Power items. I have been playing ezreal as AD for a long time but now i've gotten tired off it since its no variation in the way you play, so I decided to start playing him as AP. This build will most be about what you buy and how you rank your skills as Ezreal and what to do on lane and in teamfights. Enjoy and comment please.

Pros
Good damage output with the right items
Good finisher(not stealing but taking down escapers with low HP)
Epic in teamfights with wide damage spells(AoE)
Fast nuke who can nuke ppl from long range
Good 1v1 when he has flash ability as he can use to keep the distance from a melee
Good escaper
Cons
Squishy, very squishy
His spells is all skillshots and needs good precision and a kill can get stopped by a single creep who blocks your skillshot
Can't solo tanks
His W spell doesnt have the same long range as his Q spell which makes it harder for AP ezreal
If he gets CC:ed in teamfights he is dead.
Easy to gang-kill even if he can flash two times.(As I said a CC can kill him)
Bad farmer(Except for the ultimate he is a bad farmer)

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The Is good to have because if you meet an opponent who has magic resistance,that opponent will take some of your damage away(how much it takes away is depending on how much magic resist the target has).And with the magic penetration you can eliminate some of the target's magic resist which means you will do more damage to the target than was first intended

And i use the, and the to get an high amount of damage at the start of a game without having any good AP items.

Why i don't use flat Ap runes? Well simply cause i can't afford buying them! No just joking thats not the reason(entirely), main part of the reason is because the magic penetration gives you a good start in early game against the little magic resist every character has in base without any items. So the magic penetration helps the Ability Power runes and my spell in level one to do even more damage! If you have any other runes that you like on Ezreal/AP characters please share them with me and I will try to try them out (even though im pretty broke)!

Pretty often I play Ezreal with Clarity, But I wanted to try something else so I got flash instead of clarity and it has worked pretty well, so i have done my mastery differently than before when I tried to get some points in other stuff than mana regeneration since I used clarity. But now I go for the mana regeneration and the Neutral buff increased duration so I can have blue buff for a longer time.I will only mention the most important bits of my masteries.
I start off by getting 3/3 in Perserverance which gives me more mana regeneration which works good with my so I can use my spells to harass my enemies or get some creep kills. I get 4/4 in Awareness which gives me more xp faster in lane, this is always good to have so you dont slack behind the enemies in your lane who will level faster than you and get an early advantage.
Then I get 3/3 in Meditation to raise my mana regeneration even more.
Then I get 2/2 in Utility Mastery so I can have my blue buff up longer and that means i can pretty much spamm my spells, but it is important to get the blue buff so you can spamm your spells in teamfights.
After that i get the 3/3 in Quickness for obvious reasons and 1/1 in Blink of An Eye to reduce my cooldown on flash summoner ability.
Then i get 3/3 in Intelligence to lower the cooldown on my spells which will work perfectly well with my and/or my
After that i get the last point in the utility tree which is Presence of The Master which reduces the cooldown on my flash even more! This is everything I put in the utility tree so let's move on to the offense tree.
In the offense tree i put my last 9 point which i try to focus and get the ability power and the magic penetration. so i get 3/3 in Archmage's Savvy to give me more AP, and i put 4/4 in Sorcery to give me less cooldown on my abilities and the Sorcery will lead me over to 1/1 Archaic knowledge, which gives me even more magic penetration!!
I go with these masteries so i can get full potentiality out of my character and my runes and my items.

My items is building on 3 core attributes: Ability Power, Burst and Enough items to make that squishy hero a bit more capable to survive in teamfights(survivability,and mana)
I start off with an to give me mana regen, health and a little bit AP. gives me around 530 health without any health runes in level 1. If you use only a or a in level 1 you can easily be killed or having to recall early into the game which makes you loose xp and gold. Even thogh you can't afford any when you buy the Doran's ring the 100 health gives you an opportunity to trade first blood against a death which a health potion can not help you with. My second item is my boots: I started using these boots since i started using the which also gives me cooldown reduction, and I think I would not be using these boots if I wouldn't had all the cooldown reduction from my masteries.These boots are not the only ones you can use for Ezreal Ability power but with the masteries which gives me less cooldowns i'd like to stack a few more items on to that list of cooldown reduction such as this one.Another pair of boots you can have is which stack with my runes and my masteries. I shift between these Boots but in the end i think i like the more, which gives me a lower cooldown on my ultimate and lower cooldowns on my main spells and . After the boots i get a which gives me a good amount of mana to get around untill I get other mana items. After this I build the which gives me 500 health and 80 Ability power and an Awesome slow which gets procced by my spells. This item is great for chasing together with my and I can do my spell which passes through creeps, and that spell I can use to get the slow on my target,then i can jump to the target and unleash my wrath. You can get if you think it is better a which gives you more health plus it gives you mana which the cannot give you. After The Rylai's i get a to maximize my burst against full health targets. The deathfire grasp is not nesecary but it is a good item to get high damage on single targets and 15% cooldown reduction in early/mid game.After i have gotten my I start to build my I get the to maximize my burst and my total damage not only for burst intensions since it is not an unique active like the . I start to build an if I see that my enemy team has a wide Ability power setup in that case the magic resist might come in handy.I also use it to reduce some of their magic resistance and to get more Ability power. This is a really useful item but you can get another item if the other team does not have so many Ability power users such as the to get more magic penetetration and a good amount of Ability power. As my last item (if im not selling my boots) I get a to get some nasty auto attacks on enemies in teamfights or in 1v1 fights. The Lich Bane gives me more mana more Ability power and more movement speed, I find this item effective with its passive who after a spell is casted I can do an auto attack which will deal 100% of my Ability power in a single auto attack, this is insane damage combined with your and your spells which will deal about 700damage plus by then except for the ultimate which deals one thousand damage plus.

Optional Items

this item is good only if you get many kills or assists. I don't like this item because I dont like the idea of a player only depending on one or two items such as this one, because if you dont get any stacks with this item you have wasted gold instead of getting another item.
this is a good item and I always used to buy it but until resently I decided that the is a bit more effective with it's slow even though it does not give as much mana and health as the does.
Is another good item which gives you high amount of mana but that's all it gives if you don't have plenty of them you don't get so much Ability power, So I don't think it is worth it to have only one if you are going for much Ability power and high damage as I would like to do.

This item gives you great magic penetration and lot of Ability power.

For summoner spells I go mostly with and , BUT I do not have a good summoner spell setup yet for ezreal so I shift spells a lot. I used to go with but i felt like I could make it anyhow on the lane without it so I chose
instead to make an easy escape even easier. I wont be reccomending any spells in this guide but I will say some of the spells that I do not like to use and some of those I do like to use for AP ezreal. Some of these are : I do not like this one because My spells are not in range of the Exhaust range and I like to stay away as long away as possible. And i do not use Exhaust because I can ,IF someone runs away with low HP I can finish them with my so Exhaust isn't that nesecary to catch a runner really in my opinion, only if you know you dont have any slow or CC on your lane it can be good and appreciated. When I'm thinking right now I don't really like ignite for Ezreal because the range isn't enough for me who stands in the back with wide range. Again this is a spell for finishing, allthough I pick this spell I always forget to use it and that's not good I know but I never remember to do it because I know I can finish them off with . The reason I said I used it is because sometimes it is really good in 1v1 and, it's just only me who forgets to use it and uses instead.So I still think ignite is a good spell for ezreal but only you feel you can handle the range and remember to use it, or you could pick another spell and do as I do, just them ;). Other spell I do not reccommend is: ... No reason, just dont use it...
.. You don't need attack damage.. You are not a jungler my friend.. The other spells that I do not name are some of the spells I think you can use if you want to because they make some purpose to ezreal but I think there are some better choices in spells that can be done. You have to go on your feeling for this one I can't decide.

Why I rank before and , I have 3 good reasons for ranking up before , Essence flux does not do a random hit of damage if there are creeps nearby as Arcane shift is. Essence flux does more damage than Arcane shift in low level because it's easier to hit ,and more hits results in more damage. The Essence flux has a lower cooldown so I dont have to rely on a spell with more than 12 seconds cooldown that can easily miss its damage by randomness instead of getting a spell with less cooldown and a spell which is easier to do damage with. Why I rank before ?, simple. The mystic shot has recently been 'buffed' so now it stacks with AP too, not only with AD but the AP ratio on that spell is so low it is not worth using until late game when even then it doesn't do that much damage, so I still advice you to rank the a bit more than the but it is always good to have one rank in your for cheap creep killing and to scout bushes with your passive. In level 6,11and 16 always rank up your ultimate spell in this case .

In teamfights as Ezreal you want to open up with your to get as massive AoE damage (Area over effect damage) on your enemies as possible which will give you an easier teamfight. Always as Ezreal I like to be the one who is standing in the back dealing tons of damage to the major part of the group and then focusing on one squishy target after I have dealt a lot of damage to the enemy group with my and my which probably have refreshed since I used it to damage everyone in the enemy team, to get an easy kill during the teamfight and to help my team score an ace. Most of your job in teamfights (im focusing on late games) is to nuke their squishys and to deal as much damage as possible to everyone of their team with your which will help your team A LOT because in late game it does more than 700 damage to everyone, but take notice of that the ultimates damage will lower more and more depending on how many it passes through so dont shoot it through a group of creeps to get a silly 300 damage hit on their team.

I hope you enjoyed this guide and please comment to make me a better guide writer and share your experiences with Ezreal. Give me tips for better items and such! This was a fun guide to write and I hope you enjoyed it!
P.S you can add me ingame on EU servers if you have something to share; IhLiGhTzZ
And once more, hope you enjoyed my guide.