Weapon modifiers are enhancements that add special abilities or benefits to your character when they are equipped.
The number of modifiers your weapon can have depends on its rarity:
Common: No modifiers
Uncommon: 1 modifier
Rare: 2 modifiers
Legendary: 2 modifiers, and 1 Legendary modifier
Examples of modifiers are damage reduction, cooldown reduction, increased damage, increased defense, increased pet damage, increased mana regeneration, and more. Some modifiers even "stack," so two weapons with the same modifier can give you twice the benefit!
Modifiers can be viewed by mousing over the icon for the modifier when viewing it in Storage.