Remember when you first heard stuff like how either Steam or StarCraft 2 require you to be online for authentication purposes? That the process to play or utilize either service offline can be a bit circuitous, but at least it’s still possible to be offline. But, Diablo 3 differs in that you must be online to play at all — not just for authentication.
Executive vice president of game design Rob Pardo notes that the wealth of improvements and features Diablo 3 brings to Battle.net necessitate the always-online requirement. Specific additions that he refers to include:
