Use Trundle's strong early dueling and invade resistance to contest Karthus's vulnerable early clears and disrupt his tempo.
Prioritize river control and Scuttle fights to deny Karthus safe pathing and objective access.
Leverage Trundle's ability to force extended fights and stat steal to punish Karthus's low early game pressure and lack of mobility.
Jungle Plan
Invade Karthus early when lanes can assist or counter-gank to deny his full clear and force him off camps.
Contest river Scuttle only when nearby lanes have priority to ensure safe fights and objective control.
Use (E) pillar to trap Karthus near objectives or jungle exits and follow up with (Q) and (R) to maximize stat steal and dueling advantage.
Danger windows
Early jungle clears when Trundle is low health are risky; avoid isolated river fights without lane priority to prevent being collapsed on.
Forced Smite fights at dragon or Rift Herald can be dangerous if Karthus has vision and lanes are not ready to assist.
Post-level 6, Karthus's global (R) can finish off low-health allies after skirmishes; avoid extended low-health fights across the map without vision.
Early game
Start with a path that leads to early river Scuttle control to challenge Karthus's first clear and limit his tempo.
Look for level 3 invade windows when Karthus is low health from clearing and lanes have priority to capitalize on his weak dueling.
Avoid prolonged fights in the jungle without lane priority as Karthus can punish overextensions with his global (R) and sustained damage.
Power spikes
Level 6 (R) significantly increases Trundle's dueling power by draining Karthus's resistances; prioritize ulting durable targets before committing.
First dueling item completion enhances Trundle's ability to force extended side-lane fights and pressure towers against Karthus's weaker early presence.
Be wary of Karthus's level 6 (R) and first AP item spike, which increase his global damage and clear speed; use these timings to avoid blind objective fights and force fights before he scales.
Win conditions
Convert early invade and Scuttle control into denying Karthus's jungle tempo and forcing him into defensive clears.
Use (E) pillar and (R) stat drain to trap and dismantle Karthus in jungle skirmishes and objective fights.
Leverage Trundle's dueling strength and objective control to secure early dragons and Rift Herald, snowballing lane priority and map pressure.
Tip: For Trundle vs Karthus, read overview, trading pattern, and danger windows first for a fast Jungle lane check.
