Alongside balance changes following the Diablo 4 Season 9 PTR, Blizzard has changed how difficulties interact with the Dungeon Escalation System. While Nightmare Dungeon Escalations are now available below Torment difficulties, their entry is now very limited, and the dungeon sequence does not lead to the new Astaroth Fight.
Season 9 Overview Nightmare Dungeon Escalation Guide
Starting a Nightmare Dungeon Escalation requires that players use an Escalation Sigil, like the one below.
