On this page of the guide, you will find out whether Diablo Immortal can be played solo, as well as what functions are available in the single-player mode, and which are dedicated to multiplayer.
Diablo Immortal can be played solo, just like the other games in this universe. All PvE content on normal difficulty is available for solo players: campaign, additional activities (incl. Bounties, Battle Pass, Bestiary, Codex, Cycle of Strife), Rifts or Dungeons.
What's missing in solo mode?
PvP activities are obviously related to multiplayer.Higher difficulty levels (Hell 1-4) available after reaching the maximum experience level (level 60) require a certain number of players in the party (from 2 to 4) before entering the dungeons.
World Bosses also require some cooperation with other players who will be on the same map and want to take part in the fight.