PROS

+Everyone hates him.

+He's a blast to play.

+A little spell vamp goes a long way.

+Doesn't need to wreck his lane to carry.

+If he wins his lane, turns into a hyper carry.

CONS

-He is fairly squishy.

-It is hard to finish off kills pre-Lvl 6.

-Teammates will always blame you for not kill-securing.

-Teammates will always blame you for kill-stealing.

Sometimes you will be last pick, you should not lane against the following champions unless you are capable of extreme bad-***ery. And even then you should strongly consider playing a character better suited to counter the enemy mid/top laner. These impossible champs are:

Akali
Talon
Kassadin
Veigar
LeBlanc
Fizz
Katarina


There is one thing that is similar with all of these champs. The ability to teleport/jump, dodge, and go invisible or otherwise untargetable. They are extremely difficult to lane against due to high mobility, however they have a low range so they are not invincible. I would be wary of most of these matchups.

Other matchups that are difficult but not as impossible as the ones above are:

Ahri
Lux
Zyra - She has Heim's turrets, Lux's aoe stun/root, and Orianna's Ult (but with a bigger AoE)
Gragas
Vladimir
Fiddlesticks
Malzahar
Orianna - but only if she's a good one

Champs you should not hesitate to play Karthus against are:

Heimerdinger
Annie
Brand
Ryze
Viktor
Swain
Morgana - Stay behind minions and let them take the stun, it moves very slowly.
Xerath
Kennen - just watch out for the CC when his jungler ganks.

Karthus doesn't always get counterpicked but here's a list of counterpicks (they aren't all mid lane counters.)

Shaco
Sivir
Nocturn

The way I max my and is OPPOSITE from most Karthus builds. Here's why:

A good Karthus will hit his Q's which do more damage than if you were to leave Defile toggled on.

Wall of pain makes you faster than people chasing you, which allows you to outrun a jungler, escape ganks, and trap turret-divers under an aggro'd turret.

Wall of pain also does more in a team fight since it helps everyone hit harder due to the fact that it strips anyone who walks through it of Armor and Magic Resistance.

Brand's Blaze
Caitlyn's Yordle Snap Trap
Cassiopeia's Miasma and Noxious Blast
Fizz's Seastone Trident and Chum the Waters
Gangplank's Grog Soaked Blade
Malzahar's Malefic Visions
Mordekaiser's Children of the Grave
Nidalee's Bushwhack
Singed's Poison Trail
Swain's Torment
Talon's Noxian Diplomacy
Teemo's Toxic Shot and Noxious Trap
Tristana's Explosive Shot
Trundle's Agony
Twitch's Deadly Venom
Udyr's Wilding Claw
Urgot's Noxian Corrosive Charge
Zilean's Time Bomb
Darius's Hemorrhage

Surge is one that seems to make the most sense to me, because you will pick up an additional 35% AP off of it (once you factor in the percentage increase from Rabadon's Deathcap, Archmage , and Summoner's Wrath ) bringing the total to 115 AP and some change. That's quite a bit.

Flash is more acceptable, but not as useful late game because it is likely that if you are focused, you won't make it out alive anyways. Also if you are trying to position yourself in a teamfight, it is unlikely that this will help you more than ghost, being jumpy doesn't make you less of a target for auto-attacks.

Teleport is ok if you've been counterpicked and think you will likely be behind in creep score. It's also good for getting around during the late game or for escaping.

Revive not really a great option because of the long cooldown timer on it, but I guess you could play Revive+ Requiem and do pretty well. I can't count the number of times I've wished that I could ult but couldn't because I was dead. The more I watch LoL games, the more I think zombie karthus has become the new meta.



Ignite is a common one, but doesn't really make sense, partially because of the range of it vs the range of your Q and because you have a little while after you die to keep on casting.

Clairvoyance doesn't really make sense because you need mobility and that extra heal, it might give you sight on that guy that's running, but in the end you should be keeping track of whether or not enemies have blown their heals, spell shields, and other ult dodging skills.

Clarity is a spell that gives additional mana, but since your Defile gives you mana back, this spell seems redundant. If you're constantly running out of mana, then you need to get the blue buff more and last hit more wisely. If none of that works, recall and buy mana potions. You should not run out of mana easily with this build.

Exhaust is another redundant pick, because your wall will not only slow enemy champs, it also will strip them of armor. As an added benefit its cast range is much greater. Don't get this summoner spell.

Cleanse is the only one that makes sense, if you're getting CC'd too much, however if this is the case, you're better off getting a Quicksilver Sash.

STARTING ITEMS

+ : for a standard lane.

+ : for when you're expecting to not have to use your Health Potion much due to a lack of CC from the jungler and mid. (this is rarely the case)

CORE ITEMS

: Its just enough to counter Mercury's Treads : If you've been counterpicked for your mid lane.

Early game:

: you take this over catalyst of the protector because catalyst gives you health and mana but no regeneration, so you will eventually run out of one of the two.
: rewards you for hitting things. Take that anger out on something, son! Also in tandem with Tear of the Goddess you can convert mana into hp via your Q.

Mid/Late game

: Increased spell vamp + more AP.
: More AP.
: More of More AP
: Armor, Bling Factor, Invincibility, and (of course) AP!!

SITUATIONAL ITEMS

I have only found myself needing one of 5 additional items:

: Is great when someone decides to build a Force of Nature, also usefull for getting by Baron's Magic resistance. + More AP
: If the enemy hits as hard with AP as you do. + More AP
: More HP and Mana, also good against a caster that tends to land stuns or fears, good examples are Annie, Brand, Veigar, Malzahar, Fiddlesticks, Lux, and Morgana.
: More mana, Cooldown Reduction, and Armor... Alot of Armor.
: Gives some AP and CDR but mainly because it is a truly exceptional against Health Tanks like Dr. Mundo. Instantly takes off around half of an enemies health (once you factor in how much AP you have).

Early game


You'll want to go mid, unless you have a Vladimir or Kennen at mid, in which case you'll go top. Either way, get ready to wreck some stuff.

First thing you'll get ready to wreck is the blue buff. In some cases your jungler will ask you to damage the wolves, and its important to let him take aggro from them, conversely, you will leash the blue and head to mid. If you've only leashed the blue, then you should get there in just enough time to Lay Waste one minion right before he dies.

You'll want to refrain from casting Lay Waste any further and simply last hit minions until you hit Lvl 2 and get your Defile. Once you get Defile just try to last hit minions so that your Lay Waste only hits one minion at a time, as this will double the damage it does. You won't want to use your Defile at all because the damamge isn't really there and it costs beaucoup de mana. As a kind of reference you should aim to farm 100 minions at 12 minutes and 200 at the 20 minute mark. When your neutral monster camps (wraiths and wolves) spawn you'll want to push your lane up and then run to farm one or both of them. If it helps, there is an app that I know for sure that you can get on your android called "jungle timer" which basically allows you to tap the image associated with the neutral monster camp you'd like to keep track of. It will immediately start a countdown timer which keeps the time in seconds. This way, when you have around 10 seconds left on the timer, you know you should start pushing harder. I don't use it, but I know that for some people its a good application to use to get into the rhythm of taking your camps.

At Lvl 4 you'll get your Wall of Pain. This is extremely useful for baiting, kiting, and ganking with your jungler. It will help junglers with hard CC close the gap on your enemy mid. It will also allow you to trap the enemy jungler under your turret and force him to blow his summoner's or die.

When being the victim of a gank you want to prioritize the jungler when you throw down your Wall of Pain and spam your Q at him and the caster alternatingly. This keeps the jungler (who is often melee) from landing too much damage on you, and keeps him and the enemy caster from landing duo-CC on you. You wall the jungler because the caster can often hit you even if you have slowed him.

Sometimes you will be forced to use your Ghost and Heal to get away. Just remember, the cooldown on Ghost is much less, and therefore you use it first, and keep the Heal only as a last resort. If you get hit with an Ignite remember to use a Health Potion before you use Heal.

While roaming isn't really recommended, if you see the need to do so, make sure to check bushes with your Lay Waste as it lights up bushes and other hidden areas.

Mid game:

You should have your Requiem by your first recall, and you should be able to buy a Tear of the Goddess. You'll want to let your teammates know that Requiem is up and keep them alerted of the damage and the cooldown timer. This is important for their gank schedules. During the mid-game, you will ult to help other lanes out, only when you're sure they can finish the kill. My recommendation is to wait until they're clearly on your side of the map, and wait for your teammates to commit. Once they've committed to gank, you cast it as soon as they land the first hit. This keeps you from wasting it, and allows you to get assists (which is still gold) without being accused of Kill-stealing. Occasionally, an unexpected trade will occur and they will call for an ult, first you check the lane to make sure that the fleeing enemies are low enough, and then you ult. The cooldown is too long to waste it.

When ulting someone in your own lane, you only do it when one of two things has happened. 1- They have blown their heals and shields and are way past their turret. 2- You are dead and they are low and out of reach, if they are in your reach, use Wall of Pain in conjunction with Lay Waste.

Once the laning phase has been broken up, either by roamers from your team or from the other, you will be ganking and trapping. Karthus plays the second role very well. Many enemy champs will underestimate your suvivability onc eyou have an Archangel's Staff and Will of the Ancients. Just remember that it is your duty to land the Wall of Pain no matter what. You will want to use it to do 4 things.

1- Slow enemies chasing your teammates.

2- Slow and debuff multiple enemies during ganks.

3- Slow retreating enemies that are running from a teamfight or running from your ghost after you've died, try and keep them inside of your AoE.

4- You will use it to debuff neutral monsters like the Ancient Golem, the Dragon, and the Baron himself.

As an added benefit your Wall of Pain can grant you vision wherever you cast it.

Late game

There are two main ways to play that I've seen, suicide bomber karthus and ranged skittle-cannon karthus.

A suicide bomber runs in with Defile on, throws down a Wall of Pain and uses Zhonya's Hourglass. The he uses Lay Waste to hit for hellacious damage. Requiem is only used once Karthus has died.

Skittle-cannon Karthus is better in my opinion, because the range on Lay Waste is large enough for you to press up against a wall in the jungle and cast over it. It also allows you to back away and use Requiem without being killed before the channel finishes.

Either way, your dps should be almost as much as your ranged AD carry's.

Let's face it, wards win games. They will alert you to incoming junglers and ganks and keep you from overextending. It is a good idea to drop these bad boys whenever you're getting harassed by the jungler. Even if you haven't seen a gank but you're doing well, you should still ward, because the likelihood of a gank happening in a lane is higher when that lane is doing worse.

So here's an overview of where your team as a whole should ward.

And if you're playing Karthus, here's where you should ward:

You should ward above the mid lane here:

Unless, of course, your top and jungler haven't put a ward here:

Or here:

If they don't have either of those, you will need to sacrifice some visibility of the riverbed for some visibility of your backdoor and ward here:

On the bottom of the mid lane you should ward here:

And ward here if you find that you're having to turtle and worry about getting dived in a 4 or 5 v 1:

Lastly, you may be facing someone who goes invis frequently or drops traps and presents for you that you can't see. If that is the case, get a pink one and ward here:

-His damage.

For this I'd recommend getting some armor, some health, and some spell vamp.

-Your damage output.

This calls for some firepower, abbreviated FP AP.

-Your mana consumption.

I'd recommend snagging the Blue buff and a blue elixer.

-His magic resistance.

You'll need magic penn from somewhere, maybe items or runes?

Here are tips on how I do it.

-I will keep trying to do it sooner, but my current earliest run was when I was Lvl 17.

-So far for me, the bare minimum for this run is Rylai's Staff, Will of the Ancients, Zhonya's Hourglass, and a Void Staff

-Earlier is better: Since the Baron gains 1000 HP per 8 minutes, the longer you wait, the harder it gets. Farm like crazy.

-There seems to be a sweet spot to his left where he doesn't hit you with his disrupts as much. You need to not be pushed up against the wall (keep him in your AoE) but you also need to keep him at arms length. Get him at the edge of your AoE. You're going to want to lead in with your wall, immediately turn on your Defile, and spam your lay wastes. If he knocks you back, make sure you immediately get back closer to keep him in your AoE. Also you'll want to use Zhonya's immediately after your first wall drops. Another move you should make is to throw down your wall whenever it is available.

-Obviously the Optimal setup is very late in the game when you're fed,but you should be able to get this one much sooner.

Thanks to jhoijhoi her epic guide can be found here. Also, thanks to The_Nameless_Bard for having a decent Karthus guide which I used for the longest time, and eventually adapted to the one you see here.