KarthusAbility Order
- First three = Q>E>W
- Then, prioritize maxing:
- Q
Lay Waste > E 
Defile > W 
Wall of Pain
- Q
Summoner Spells
Flash + 
Teleport
Use your favourite features in-game with our Desktop AppAbility Order + Summoner Spells
Items
Starter Items
Full Build
Runes
- Marks
Greater Mark of Magic Penetration x9
- Seals
Greater Seal of Armor x9
- Glyphs
Greater Glyph of Magic Resist x9
- Quintessences
Greater Quintessence of Ability Power x3
For our runes we're going for a mix of Ability Power and defensive stats. 
Karthus can have a rough laning phase against aggressive opponents, so the extra resistances help you survive long enough to farm safely. Your main goal during the early game is to pick up as much CS as possible so you can get your core items and begin scaling into the late game.
For Marks, we'll be taking Magic Penetration to increase our damage throughout the game. Quintessences are Ability Power, giving us a stronger early game and making it easier to last hit and harass with Lay Waste.
Our Seals and Glyphs are dedicated to defense, taking Armor and Magic Resist. If you're facing a team that's heavily AD or heavily AP, don't be afraid to swap them out and stack the appropriate resistance instead.
Masteries
The mastery setup is pretty obvious. We're going to put the maximum amount of points into the Offense tree because Karthus is all about dealing as much damage as possible.
Every bit of AP and magic damage helps, especially when it comes to making your ultimate hit even harder. For our second tree we'll be taking Utility. The extra mana regeneration is a huge help during the laning phase, allowing you to spam Lay Waste more often without running out of mana.
The improved Recall also lets you get back to lane quicker after shopping, meaning you miss less farm. All of this makes it much easier to keep your CS up, hit your item timings faster, and become the late game monster that Karthus is known for.
Changes for Classic
No Changes.
Table of Contents
Overview
Our experts are currently testing LoL Classic builds for Karthus on the PBE.
Check back often as we make updates based on PBE changes and as the Classic meta develops!
How to Play
While playing Karthus your priority is to farm as efficiently as possible. Use Q to secure minions while poking your opponents whenever they're isolated as your spell will do more damage. Avoid unnecessary trades early, as your lack of mobility makes you vulnerable to jungle pressure.
Don't be afraid to die if it means securing an important kill or winning a fight, your passive often allows you to deal loads of damage after death. Once level 6 arrives and you have a few AP components, keep checking side lanes for low health enemies and use your ultimate to pick up kills across the map.
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