Offhand items are exactly what it says on the tin: Items equipped in the off-hand slot alongside your weapon. These are not necessarily shields.
List of offhand items[edit | edit source]
Grants Star's Kiss ability: Next enemy that makes a melee attack on the character is knocked down for 1 round
Quest reward for completing Wayward Son.
Attackers are Hobbled (-15% Evasion, -50% Move Speed)