Hi guys, this is my guide to Karthus jungle. Karthus can be an amazing jungler because of his extremely high clear speed, global presence with his ult, and strong Predator ganks, a keystone that also gives him bonus damage on his ult.

While a midlane Karthus can be easily abused and quickly become free food for assassins or burst mages, a jungle Karthus is overall a much safer blind pick in any game and can just play reactively on the map in a bad jungle matchup, focusing on fast farm and ganks.

Have a nice read!

Rune page is very straightforward stat boosts and cooldown reduction.

Predator gives you both greatly increased gank pressure and increased damage on your ult. If you Requiem when predator is active, it deals the predator bonus damage to the lowest HP enemy champion, making it a big boost for finishing off low HP targets.

Transcendence + CDR stat shard + Archangel's Staff puts you close to 40% CDR very early in the game, which massively improves your clear speed by spamming Q as well as allow you to have your ult up all the time. The downside of many Karthus builds is that they sit at low amounts of CDR since AP tank items don't give any, so this is the best way to max out on it.

You max Lay Waste first because it's Karthus' best damage/clear skill, and Defile second because the AOE damage is huge in fights, especially for punishing people who try to constantly dodge your Q, also helps your jungle clear after tear.

Defile at level 2 helps clears the raptors (don't use it on any other camp), and by the time you completed the full clear you get Wall of Pain at level 4 for ganking.

I recommeng going Hunter's Talisman -> Boots -> Archangel's Staff in every game.

It may sound counter-intuitive to skip the jungle item Stalker's Blade - Runic Echoes but there's a reason for it. Runic echoes doesn't solve Karthus' mana problems since it doesn't give him a big enough mana pool to cover the massive cost of Defile in a fight, so with it you'll often run out of mana. Runic echoes doesn't give enough cooldown reduction either, while with the 20% CDR from archangel's plus the 20% CDR from your rune page, you'll reach 40% CDR very fast naturally. While archangel's is an expensive item, when you factor in the Fiendish Codex that you'd have to buy anyways if going for another build, it's actually a very cost-efficient buy.

The full magic penetration build will give you more damage than anything else you could buy. Always buy Oblivion Orb and later upgrade to morello for the magic penetration even when not facing healing, the way magic pen works is that it synergizes with itself since every source of it brings the enemy MR closer to zero, so the more you have the more effective it becomes. Even without any MR item or rune a melee champion sits at 53 MR, so you need the three penetration items to bring that to zero. I don't build Rod of Ages because morello is just far more damage, try it out in practice tool if you don't believe me.

Maximizes your damage, especially on your ultimate.

Situational items to deal with assassins , but you already have 40% CDR with my build without one of those and Death Defied generally means you don't mind getting focused first in a fight so you can do without. The only cases where you absolutely need one of those is when facing champions that can oneshot you from long range like Zoe or LeBlanc, making your passive useless.

- Starting red buff is better. You don't need the mana regen from blue buff, you only need HP regen, and most importantly the red buff has magic resist so it's very hard to solo early.

- Always go for a full clear (red->blue side->scuttle typically)

- Karthus is not bad at contesting scuttlecrabs early. Don't expect kills but Q+smite is solid for securing the crab and Q poke is good zoning. You're also very safe since you can just disengage with Wall of Pain.

- Don't counterjungle aggressively, but always do it reactively when you see the enemy jungler on the other side of the map.

- While he has decent ganking ability, Karthus is still at the core a farming jungler, and his biggest strength is his ability to flashfarm the entire map. Always clear empty lanes whenever you can.

- Time your ultimate right. Either you use it at the start of a fight so you can get assists, or at the end of a fight to pick off low health champions who are fleeing. But avoid using it in the middle of a fight since the enemy champions may die before you get the assist.

- When you die, you have time for 3 Lay Waste casts before your ultimate.