Starscourge Radahn is a major Great Rune route and one of Elden Ring's most distinctive large-scale encounters. The arena, summon signs and long-range opening make it play differently from a small enclosed boss fight.
Opening approach
Expect strong long-range pressure before you reach melee distance. Use the size of the arena instead of rushing in a straight line, and summon allied fighters when that fits your approach.
Use the festival structure
The fight supports multiple summon signs in the arena. Those allies can create breathing room and split attention, especially while you are learning Radahn's attack timing.
Preparation checklist
- Bring enough Vigor to survive high-damage mistakes.
- Use reliable mobility for the large arena.
- Keep healing available for later phases.
- Use a weapon or spell setup that can maintain damage after repositioning.
Later-phase pressure
The fight becomes more chaotic as it progresses. Do not sacrifice positioning just to keep attacking; surviving a dangerous sequence is more valuable than forcing one extra hit.
Build adjustment
If you struggle to stay close enough to deal damage, prioritize mobility, range or safer attack windows. If you die in only a few hits, survivability is the more urgent problem.
Reference: GameFAQs walkthrough.