Expertise (WoW)  

Expertise is an attribute that decreases the chance that melee attacks made by the player will be dodged or parried by 0.25%. Also, some classes and races gain an additional bonus to their Expertise rating.

What is Expertise

Different from weapon skill, expertise is not limited to a specific weapon type. The only exception to this is the racial bonus^[1] which only receives the +5 expertise bonus when a weapon of that class is equipped.

The terms expertise and expertise rating are also different in their use. A player's "Expertise Rating" is gained from their equipped items and for every 3.92 expertise rating gained, 1 "Expertise" is added at level 70. Expertise is usually gained from talents however, and for each 1 point of expertise you reduce your chance to be dodged/parried by 0.25%. So, with this in mind, you would need an expertise rating of 15.68 at 70 to reduce your chance to be dodged or parried by just 1%.

Expertise from Class Talents

• Paladin: They can gain up to 5 points of expertise from the Combat Expertise talent, found in the Protection tree.
• Rogue: The Rogue can gain up to 10 points of expertise from the Weapon Expertise talent, located in the Combat tree.
• Warrior: A warrior can gain up to 6 points of expertise from Defiance, available in the Protection tree third tier.

Expertise from Racial Traits

• Humans gain 5 expertise from their Sword and Mace Specialization trait when using a sword or a mace.
• Orcs gain 5 expertise from their Axe Specialization trait when using an axe.

As the Front Line Tank

Expertise is used several different ways on a tank. For starters, it's used to reduce avoidance and it increases threat generation^[2]. And secondly, because some mobs can attack faster after a parry, a higher expertise rating will reduce the total damage the tank takes by reducing that parry chance.

As Melee DPS

Melee DPS will also benefit from a high expertise rating. With enough expertise, melee classes are also able to attack their target from the front without being dodged or parried^[3].

Notes

1. ^ Such as the Sword Specializations available to humans
2. ^ More of the tank's attacks will land
3. ^ Although standard restrictions, like Backstab or Shred, do still apply

World of Warcraft Wikibase™