Updated Wed, Dec 14, 2011 by Martuk
The mesmer can make use of Illusion magic to aid them in combat. The two types of Illusions, Clones and Phantasms, can be wielded against enemies, each capable of summoning illusions to aid the mesmer. The mesmer also possesses magic such as Shattering, which allows them to shatter an illusion for a number of secondary effects capable of either dealing damage, stunning or
dazing confusing enemies and gaining a beneficial reflective barrier.
Source: Guild Wars 2 website