If you played the already-released Diablo 3 game on PS3 or Xbox 360 then good news: you can transfer your characters’ progress into the new game – Diablo 3: Ultimate Evil Edition – when it comes out later this month (19th).
You can also transfer your characters onto PlayStation 4 and Xbox One, regardless of whether you played the older game on PS3 or Xbox 360.
Do note, however, that you cannot transfer saves from PS3 to Xbox 360, or vice versa, nor can you transfer from PS4 to Xbox One or vice versa. You also cannot transfer from PC to console.
If you’re playing the Ultimate Evil Edition on the same console as you did the standard Diablo 3 game then you need do nothing but play the game and it will automatically find your save file.