In general, monsters in higher difficulties (Nightmare, Hell, and Inferno) move faster than the monsters in previous difficulty levels; their projectiles also move faster. It’s not all bad news, though — higher–level items, unique crafting components, and new armor appearances are present in each subsequent difficulty, too. Here are a few specific changes:
The effectiveness of the Life Steal affix – which restores your Life by a percentage of the damage you deal – is reduced in advanced difficulties, as shown:
Powerful creatures are resistant to control–impairing effects like stun and slow (also referred to as “crowd control” abilities), and their resolve only grows stronger in higher difficulty levels.
Resistances are generally straightforward – they reduce the effectiveness of the skill used by the percentage given. For example, a skill that would normally stun a creature for 5 seconds will only stun a champion monster on Nightmare difficulty (50% stun resistance) for 2.5 seconds.
Creatures with resistances to certain ability types also have minimum thresholds that have to be met before the abilities have any effect. For example, if a boss on Hell difficulty (70% stun resistance) is subject to a 1.5 second stun, it would be reduced to 0.45 seconds – which is below the boss’s minimum stun threshold of 0.5 seconds – and thus be completely ignored. If you attempt to knockback that same boss and can't hit it over 21 yards, it won't budge an inch.
Movement and attack speed reductions (also referred to as “ER” or “effectiveness reduction”) modify the magnitude of the effect, not its duration. For example, a 60% movement speed slow used against a champion in Inferno will be reduced by 40%, for a 36% movement speed slow effect. Consult the chart below for details.
|Name||Stun Resist||Stun Minimum||Root Resist||Root Minimum||Move Slow Resist||Attack Speed ER||Knockback Minimum|
Once you've reached level 60, defeating certain enemies grants you a temporary boost to your abilities called Nephalem Valor. This lasts 30 minutes, persists through death, and stacks with other Nephalem Valor buffs up to five times. Each Nephalem Valor buff provides a 15% increase to the Magic and Gold Find statistics, as well as experience gained towards Paragon levels. Characters who’ve reached the maximum of 300% Magic and Gold Find can add another 75% with five stacks of Nephalem Valor, for a total of 375%.
In addition to bonuses to magic and gold find, an active Nephalem Valor buff grants one extra drop (one additional piece of random loot) from certain bosses for each stack of the buff that you have.
WARNING – SPOILERS AHEAD!
The bosses who provide bonus Nephalem Valor rewards are: