League of Legends S12: Karthus Mid Build Guide

From runes to items, gameplay tips amd more, we've put together a guide to help you master playing Karthus in the midlane in League of Legends.

Be mindful that there are several ways to build and play a champion, and you'll need to be adaptable as the game and the enemy team progress.

That said, this guide is a good starting point to helping you get to grips with the champion and making an impact in your games.

Runes

Core Items

Liandry's Anguish

3200 Gold

Zhonya's Hourglass

2600 Gold

Build

Liandry's Anguish is a great item on Karthus, adding a burn to any damage he deals. This amounts to a lot of pain over time, particularly against beefier targets. 

Zhonya's Hourglass helps with survivability, especially when he's exposed. 

Other good items include Morellonomicon, Shadowflame, Void Staff, and Rabadon's Deathcap.

Starting Item & Boots

Health Potion

50 Gold

Doran's Ring

400 Gold

Sorcerer's Shoes

1100 Gold

Skill Order

While your choices may differ according to how the game progresses, the typical Karthus skill priority is:

R > Q > E > W

Summoner Spells

These are the summoner spells most typically taken by Karthus in this role. Naturally, this may change depending on match-ups.

Gameplay

You'll need to be aggressive on Karthus to win the lane match-up, but remember that he has quite low mobility and is therefore susceptible to ganks. You have a lot of tools to get around and zone your enemy, and of course you'll deal the most damage with your devastating global ult. Make sure you have plenty of vision, and just try to control the lane as best you can.

• Level 1 - Take Q - Lay Waste, a low-cost ability that deals big damage early on. Spam it to farm minions. 
• Level 2 - Take E - Defile, and toggle it on and off to deal the splash damage to minions and last hit to restore mana.
• First Back - Pick up a Lost Chapter to help with the mana management. 

Tips & Tricks

• Both Lay Waste and Wall of Pain grant vision, so use them to check bushes when your wards are on cooldown.
• Remember that Defile restores mana if you kill an enemy unit or break a turret. It's expensive to keep on all the time, at least in the early game, but toggling it on and off to last hit works well.
• Wall of Pain also reduces magic resist of enemies passing through it, which can aid allies in a teamfight. 
• If you find yourself killed, make sure you channel your ultimate before you fully die. Generally speaking, you'll have enough time to use three Lay Wastes then Requiem.