All damage done to enemies within 15 yards of the Wizard increases by 30%.
Audacity is a Wizard passive skill, unlocked at level 66.
Damage increase is multiplicative to all other modifiers.
This ability, predictably, is most useful for melee Wizards.
Hydra deals additional damage to enemies within 15 yards of the Wizard, not of itself.
Power Hungry serves as a direct opposite of this skill.