Diablo III to be harder than hell - at Inferno difficulty
And in an interview with Kotaku, the Blizzard Entertainment game director Jay Wilson said that the fourth and toughest difficulty for Diablo III is aimed at players who have reached the level 60 player cap.
"The idea was that we wanted a difficulty mode where the entire game was viable," said Wilson. "So you don't have to pick and choose key areas [to replay]." He further says that it will be very challenging and very difficult which Blizzard hope will balance out the end game for the diehard Diablo players.
The 61 or higher-leveled players will be battling enemies with increased health, damage, damage resistances and aggression.
To reward players to go into the Inferno, some armor, weapons and items will be dropping exclusively in Inferno. These items will have a distinct visual appearance.
Kotaku.com - Source