Some console players discovered an interesting phenomenon: if they put their PS5 into sleep mode while Diablo IV was running in the background, they could disconnect from the internet and continue playing for approximately two hours before the game forced a re-sync. While this demonstrates that at least some game content can run locally, it is not a true offline mode and offers only a temporary, unreliable workaround.
Blizzard has justified the always-online requirement on several grounds. Chief among them is the game's shared-world design, which Blizzard has described as featuring an open world where players naturally encounter each other. The game is designed to function like an MMORPG, where the world is populated with other players (whether strangers or friends) who can join in for world events, world bosses, and other large-scale encounters. From a technical architecture perspective, the game constantly synchronizes data between the player's client and Blizzard's servers. This is not a traditional single-player experience where the game runs entirely on local hardware; rather, it is a client-server model that requires ongoing communication to function.
The always-online requirement has not merely been an abstract inconvenience; it has led to tangible, frustrating real-world consequences for players. When Blizzard's servers experience problems, the game simply becomes unplayable.
