An Off-hand object can be wielded by a character that uses a one handed weapon such a Sword, Axe or Wand. An Off-hand can not be wielded when a character uses a Two handed weapon such as a Bow, Staff, Hammer, or Daggers.
Off-hand items are split into two categories:
Off-hand is also used as a short-hand to refer to the Assassin's Off-Hand Attack.