attribute ?

Expertise:
Expertise is the Ranger's primary attribute. Every rank in Expertise reduces energy costs on any attack skills, preparations, or traps by 5%. At skill rank 12, energy costs are reduced by 60%. It is highly advisable to have a high Expertise rank as it not only increases the power of all its linked skills but also reduces energy cost on other attack skills as well, even from other professions or attributes.

Does the increase in power and decrease in energy cost work for Elementalists? I know it says even other professions, but I don't know if the elementalists air and fir are considered "attack skills"

anything listed as a "spell" will not be affected by the expertise bonus. since most skills in the air and fire line are considered spells, expertise will not help an elementalist all that much.

Where are you reading that? Expertise has been reduced to 4% and I'd like to clean up the old numbers so people don't get confused.

Spells are not attack skills. They're spells. Attack skills are those skills that have type "Melee Attack" or "Bow Attack" or the like.

Peace,
-CxE

On the main page, take the link on the left to professions, and then Ranger. Scroll down to attributes.

you are right

change as soon as they can

Fixed. Thank you for the heads up.