The Capstone Dungeons are one of the primary pieces of endgame material that players can take on and complete in Diablo 4. They contain the same basic principles as any other dungeon in the game, but they represent a much tougher challenge than any other one you might have completed prior.
You can’t unlock the ability to complete a Capstone Dungeon until you have completed the main campaign in Diablo 4. The first Capstone Dungeon can only be done on World Tier 2, will require you to be roughly level 45-50, and upon completion, will give you access to World Tier 3: Nightmare, which features tougher enemies but more XP, gold, and better loot drops. While there is a second Capstone Dungeon you can complete to unlock World Tier 4 in Diablo 4, we’ll be mainly going over the first one in today’s guide.
Starting the first Capstone Dungeon
When you see the end credits roll and hop back into Diablo 4, you will go on a couple of short quests that are considered the “Epilogue.” After completing these, you can look at your quest list, and under the Priority Quest tab, you will see a new task titled “World Tier 3: Nightmare.” This quest has a level recommendation of 50, but we were able to beat it as a level 48 Sorcerer, so you don’t have to be right at level 50 to start it, or perhaps even prevail.