Dual Wield, as the name and tooltip suggests, allows a character to equip a damage-dealing weapon in your offhand. Candidates include items marked as 'One-Hand' or 'Off Hand' weapons, as 'Main Hand' items can only be equipped in your main hand. To utilize your dual-wield capability, simply place a qualifying weapon into your off-hand. This action will have two side-effects on your character: Damage dealt by the weapon in the off-hand will be reduced by half. Chance to miss with auto-attacks in both hands is increased by 19%. Since the base miss-rate with one weapon equipped is 5%, your base miss rate as a dual-wielder increases to 24% as long as you have two weapons equipped. This can be mitigated by equipping weapons and armor that improve your hit rating. Dual Wielding vs Equipping a Two-Handed Weapon Determining whether you will deal more damage via a two-handed weapon or two one-handed weapons can be accomplished a few different ways. The easiest way would be with an add-on to the game that tracked DPS. With such an add-on installed, you can simply use the target dummies in a capital city to gauge your damage output. Simply ensure that you are unbuffed, reset your damage tracker add-on, and auto-attack the dummy for 5 minutes. This will give you a good idea of your overall weapon DPS in your current gear. Swap weapons, then try again with your new setup. If you do not have the weapons on you, but instead are theorycrafting, you can utilize the following formulas: Dual Wield: Effective DPS = 0.76 x ( Main Hand Weapon's DPS] + ( 0.5 x Off-Hand Weapon's DPS] ) ) 2-hander: Effective DPS = 0.95 x 2-handed Weapon's DPS] Whichever number is higher reflects the combination that will deal more base damage. Note that these formulas do not take into account crit rating, increased hit rate gear, attack power, or any other stats that your character might have from gear. They also do not take into account abilities you might have as a result of your class, race, or gear. As such, it is only a general idea of how the weapons themselves stand alone.