Earth Magic

Earth Magic is an Elementalist secondary attribute meaning that any character with an Elementalist for their primary or secondary class can put points into this attribute.

Guild Wars Description
"No inherent effect. Many Elementalist skills, especially spells which protect you or your allies or deal earth damage, become more effective with higher Earth Magic."

General Description
Earth Magic, like Water Magic and unlike Fire Magic and Air Magic, has a mixed bag of skills. There are a large number of protection skills here, but there are also some surprisingly strong damaging spells as well.

First up, the protection skills. Armor of Earth and Kinetic Armor both give you an armor bonus, while Magnetic Aura blocks 75% of melee attacks. All together, these three give a melee attacker a great advantage. Earth Magic also possesses three ward skills: Ward Against Foes, Ward Against Elements, and Ward Against Melee, all of which, when used at the right time, can give your party the edge.

Anyone who has ever fought a Sand Elemental knows Earth Magic skills pack quite a punch. Stone Daggers and Stoning cause large amounts of damage to a single foe, while Earthquake and Aftershock deal large amounts of damage to many foes. Aftershock is particularly powerful, dealing extra damage if the foe is knocked down, and possessing a low energy cost and near-instant cast speed.

Two particularly useful Earth Magic spells are Obsidian Flame and Crystal Wave, which both ignore the opponent's armor (Crystal Wave ignores magic resistance as well) and deal direct spike damage. Both, however, have drawbacks. Crystal Wave hits all adjacent enemies, but cures them off all conditions. Obsidian Flame targets only one enemy and has a very low energy cost, casting time, and recharge time, but causes exhaustion. If necessary, an elementalist with Mesmer as a secondary profession can cast either Echo or Arcane Echo and then Obsidian Flame. Since the spell has such a low recharge time, the caster will be able to use both copies of the spell multiple times in a short period of time, dealing extreme amounts of damage. This will, however, cause severe exhaustion, putting the caster out of the fight for a little while.

Earth Magic is a favourite attribute of warrior primaries because of its bonuses to melee attackers, and also because of the area-of-effect spells that effect everyone around the caster. For a melee attacker, this is quite a lot of people. A deadly tactic is using Backbreaker as a hammer warrior to knock down a foe, then using Aftershock to deal huge amounts of damage. However, Earth Magic is diverse enough to be used by all professions.