Audacity

Audacity is a  passive skill, unlocked at level 66.

In-game
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.

Trivia

 * The face on the icon is taken from a screenshot from the 2008 Wizard class trailer.
 * Confidence Ritual, a Witch Doctor skill of almost identical functionality, also has a nearly identical style of icon.