Diablo 4: 10 Huge Things It Must Fix From 3
1. Constant Internet Connection Required
Though multiplayer gaming always has its benefits (and faults), almost every gamer out there loves to, from time to time, play by themselves, disconnected from the rest of the world. Unfortunately, Blizzard completely threw away that option, as Diablo III required players to be online all the time, including for the private, single-player experience.
This was a crippling blow to the game’s reputation, and naturally, this had a snowballing effect on the game’s servers. Since people couldn’t enjoy the game without being connected, Blizzard's servers crashed constantly over the first few days of the game being live. It was such a persistent problem that it dominated Diablo III’s media coverage, the term ‘Error 3007’ becoming an in-joke of its own.
Even after Reaper of Souls, if you want to play Diablo III by yourself, that means having a constant and strong connection; otherwise you can expect significant lag and errors. And God help you if Blizzard needs to update the game; all the servers shut down, and you'll find it very cumbersome to get back online.
That is why, when Blizzard makes Diablo IV game, it will need to have the same old sandbox single player mode that does not require an internet connection, like Diablo I and II. There have been too many spectacular failures on Blizzard's part when it came to managing servers and update issues, and hopefully they've learned from their mistakes to not repeat them in the next instalment.