Enemy Critical Strike Multiplier Reduction
It's a percentage reduction applied to the part of the enemy's critical strike multiplier that is above 100%.
So if the enemy has a critical strike multiplier of 150%, and you have 10% reduciton from this stat, it takes the 'extra' value of 50%, and reduces it by 10%, to 45%, giving an effective crit damage multiplier of 145%. The amount of damage above a regular hit that the crit would cause, is reduced by 10%. Last edited by Mark_GGG on Apr 5, 2013, 12:45:02 AM
 
Because stacking enough of that stat would cause a crit to do less damage than a regular hit, which we specifically wanted to avoid. Hence why it only reduces the 'extra' damage, so the crit can never be reduced to be less effective than a regular hit.
 
Players have a base critical strike multiplier of 150
Monsters have a base critical strike multiplier of 130, by default. It's theoretically possible that certain types of monsters override this base value, but I doubt any do.  
"This is not true. reflected damage is only about the amount, no reflection is capable of being a crit. Also, turns out these passives were reducing all extra damage from enemy crits, even if you just have one passive, due to a rounding error (the multiplier was treated as an integer, so any multiplier below 100% rounded to 0). Expect that to be fixed in 0.10.7. Last edited by Mark_GGG on Apr 18, 2013, 12:43:13 AM
