In Elden Ring, Starscourge Radahn’s a formidable demigod who roams Caelid’s eastern desert. You need to kill Radahn to start the DLC, Shadow of the Erdtree, but before you can challenge him, you need to trigger the Radahn festival.
When the festival’s active, Starscourge Radahn’s boss fight becomes accessible at Redmane Castle in southeast Caelid. It’s a simple process, if you follow our instructions.
How to start the Radahn Festival in Elden Ring
There are two ways to trigger the Radahn Festival in Elden Ring: Reach Altus Plateau or progress Ranni the Witch’s questline far enough to learn the secrets of Nokron. I suggest using the Altus Plateau method as you naturally reach the region while playing. If you’re pursuing Ranni’s quest anyway, that might be the quicker method of the two.
A) Reach Altus Plateau
There are two ways to get to Altus Plateau: Use the Grand Lift of Dectus in the northern portion of Liurnia of the Lakes, or ascend by foot through the Ruin-Strewn Precipice at the bottom of the valley. The lift’s the path of least resistance, but you need both halves of the Dectus Medallion to activate it.
Conversely, you don’t need the medallion to access Altus Plateau through the Ruin-Strewn Precipice, though you’ll fight a Magma Wyrm boss, which can be challenging for low-level characters.
If you want to use the Grand Lift of Dectus, you can get the right half of the Dectus Medallion in a chest up a ladder in Fort Faroth, in Caelid. The left half is in Fort Haight, in the east of Mistwood in Limgrave. Once you’ve collected both halves and ascended the lift, or reached Altus Plateau via the Ruin-Strewn Precipice, head back to Redmane Castle. You can get straight inside using the teleporter at the Impassable Greatbridge.
Proceed through the castle until you encounter NPCs in a courtyard. Continue up the stairs and speak to Witch-Hunter Jerren overlooking the courtyard to begin the Radahn Festival. Head into the building ahead and down the elevator to challenge the boss.
B) Progress through Ranni’s questline
You can start Ranni’s questline after clearing Caria Manor and defeating the location’s boss. The area in the top left of Liurnia is home to a tower named Ranni’s Rise, and inside, you can meet and speak to the Lunar Princess.
After going through her dialogue, you can choose to serve Ranni. Before you leave Ranni’s Rise, however, you’ll need to speak to the spectral forms of Blaidd the Half-Wolf, Perceptor Seluvis, and War Counselor Iji that can be found on the lower levels. This is necessary, with the game not letting you leave the tower until you’ve completed your conversations with all three NPC spirits. After that, you’ll need to start the questline that takes you to Siofra River via the well in the Mistwood.
Head east through the underground zone until you find Blaidd overlooking a ledge. Speak to him and exhaust his dialog, then head to Seluvis’s tower, south of Ranni’s Rise. Speak to Seluvis about Nokron and follow his instructions to find Sellen near the Waypoint Ruins. You’ll need to take out a boss underground before speaking to Sellen, but it’s fairly easy.
Return to Blaidd and speak to him about fighting Radahn, then venture out to Redmane Castle courtyard. After all of this, you can now head upstairs and speak to Witch-Hunter Jerren to begin the Radahn festival and battle Starscourge Radahn.
