The original Diablo supported multiplayer games with up to four players.
Blizzard North released Diablo for Windows in 1996, combining real-time combat, randomly generated dungeons, character development, and online play. Multiplayer was available through Blizzard’s Battle.net service, as well as through other network arrangements depending on the version and platform.
The four-player limit applied to the original game rather than later Diablo titles. Diablo II expanded the possible game size to eight players, which is a common source of confusion when players remember the series as a whole. Diablo III later used a four-player limit for online cooperative games, but that was a separate design decision.
The compact party size helped the first Diablo preserve its tense dungeon-crawling atmosphere. Players could cooperate as warriors, rogues, or sorcerers while fighting through the cathedral beneath Tristram.