Off-hand on the paper doll.
The off hand, (AKA off-hand or offhand), is the second weapon slot all characters have access to in Diablo 3. While some characters can dual wield some types of weapons, all classes can hold a shield in the off hand slot, and several classes have one specific type of item that they can equip in their off hand.
- Barbarian: No specific off hand, but can dual wield most one-handed weapons, and use a shield.
- Demon Hunter: Quivers are her intended off hand item. She can also dual-wield hand crossbows and use a shield.
- Monk: Like the Barbarian, Monks can dual-wield most one-handed weapons, or use a shield.
- Witch Doctor: The mojo is the off hand item for the Witch Doctor, or they can use a shield.
- Wizard: The source is the off hand item for the Wizard, or they can use a shield.
None of the characters in Diablo 3 can use two-handed weapons with one hand, so whenever a character equips one, there is no off hand option available. (Which contributes mightily to the general disuse of two-handed weapons.)
Dual Wielding
The Barbarian, Demon Hunter and Monk can dual-wield many types of weapons, but dual wielding is not generally considered using an "off hand" item. There are some odd wrinkles: a number of Barbarian skills such as Whirlwind and Sprint: Run Like the Wind derive their damage entirely based on the main hand weapon. This enables players to equip lower damage weapons (such as daggers) in the off hand to boost their attack speed, Life Steal or Life on Hit, mainstat or other such bonuses without sacrificing damage via their main skill attack.