There are four different difficulties in Diablo III: Normal, Nightmare, Hell and Inferno. Each difficulty level spans the entirety of the game and as a character finishes one difficulty the next is unlocked. Each character thus must start in normal and progress onward from there. Once a character has unlocked new difficulties the previous ones can still be visited if the player wants to help a friend or do something else there.
The first three difficulties have been a staple for the series ever since the very first game, but the fourth difficulty is a new concept introduced in the third installment of the series to provide playes with an increased challenge and a wider end game. A problem with the first two games was that characters who completed Hell, the final difficulty back then, rarely played outside of the later parts of the game. In Diablo I this meant farming in the Hell levels, in Diablo II it meant Baal runs, Chaos runs, killing Uber Diablo and clearing Chaos Tristram. The other areas of the games, despite also being of the highest difficulty, were rarely visited (with a few exceptions) since the monsters were weaker and the drops worse there compared to the later parts of Hell.
Monsters in Inferno difficulty will be of roughly equal level and strength across all four acts to allow for the entire game to be viable at the end, and as such it will only be available to level 60 characters looking for a greater challenge.
- Monsters are at least level 61
- Higher monster health, damage, and damage resistances
- Improved monster AI and aggression
- Increased number of Super Unique Monsters and attributes, including attributes only found in Inferno
- Increased quality of loot