Guild Wars description
"No inherent effect. Many Mesmer skills, especially spells which generate energy and reduce damage, become more effective with higher Inspiration Magic."
Inspiration Magic is a very important attribute for Mesmers. Whereas Domination Magic is focused on disrupting foes and dealing damage, Inspiration Magic is focused on disrupting foes while healing either the Mesmer's health or energy, or simply protecting and healing the Mesmer in various ways. A good example of the similarities and differences between Domination and Inspiration Magic is the Domination skill Shatter Enchantment and the Inspiration skill Drain Enchantment. Shatter Enchantment removes an enchantment and deals damage to the target foe, whereas Drain Enchantment removes an enchantment from the target foe while restoring the caster's energy and health.
Perhaps where Inspiration Magic shines is in gaining energy for the caster. An amazing 23 skills (out of 39) help you gain energy in some way. Energy Drain, and Energy Tap steal energy from your foes, providing the dual benefit of denying your foe energy while giving yourself more. Drain Enchantment, Drain Delusions, Inspired Enchantment, and Inspired Hex (and their Factions counterparts Revealed Enchantment and Revealed Hex) remove hexes and enchantments and give you energy. Power Drain interrupts a spell and gives you energy, while Spirit of Failure gives you energy whenever your foe fails to strike in combat. Several mantras (see next paragraph) give you energy in addition to their myriad effects. Power Leech steal foes' energy when they cast spells. Finally, the strange skill Ether Lord gives your foe energy degeneration, which you receive as regeneration.
An important chunk of Inspiration Magic skills are the Mantras, which are stances (with the exception of Mantra of Recall) meaning you can only have one active at a time. However, they do not reduce your energy regeneration when active, and they last quite a long time. Some Mantras provide protection from different things. An example is Mantra of Flame, which reduces damage dealt to you by fire attacks, and grants 2 energy whenever it does this. Another is Mantra of Concentration, which prevents you from being interrupted. The other type of Mantra is one that increases the effectiveness of certain types of skills. For example, Mantra of Persistence increases the duration of Illusion Magic hexes.
Inspiration Magic is also singular in its mastery over Signets. It has no fewer than three skills which cause Signet rings to recharge more quickly or even instantly, as well as five very powerful Signets for amplifying one's own power (such as Keystone Signet, Ether Signet and Hex Eater Signet, which also removes hexes from allies), disrupting an opponent (Signet of Humility) or both (Leech Signet). Many Signets, be they the already powerful Mesmer Signets or others such as Monk or Necromancer Signets, change from "handy yet forgettable" to "devastating" when properly augmented by a crafty Inspiration user.
Inspiration Magic is also one of the best defenses a Mesmer can have, primary or secondary. Ether Feast is a quick-casting, quick-recharging self-heal, while Physical Resistance and Elemental Resistance add 40 armor to their respective areas, but cause you to lose 24-12 armor in the opposing areas. (resulting in halved damage, in the absence of other modifiers), a feat matched only by an extraordinarily high level of Dolyak Signet or greatly surpassed by certain Earth Magic skills. In PvP, Physical Resistance is a wonderful option for a Monk/Mesmer who is often beset by attacks from pesky warriors early on. While Domination Magic punishes foes for attempting to harm you, and Illusion Magic lessens their ability to do so, Inspiration is great for minimizing the damage once they actually get to you.
Many skills in Inspiration Magic are extremely effective even with very few points put into them. Leech Signet, for example, is a nearly instant and free skill which can interrupt anything, from a Spell to an Attack to another Signet, which is useful even with 0 points in Inspiration. Inspired Hex and Inspired Enchantment are very nice hex- and enchantment-removal skills which require very few points to break even energy-wise. On a similar note, Hex Eater Signet can remove hexes from 3 allies at no energy cost (even gaining a very small amount of energy) with no points at all in inspiration magic. Mantra of Concentration lasts long enough to prevent its single interrupt with hardly any points, and with only a bare handful of leftover points invested for Channeling, it can be kept up indefinitely. Even if you cannot or do not wish to afford to place 10, 12, or more points in Inspiration Magic, that does not mean that its skills will prove to be useless for you.
All in all, Inspiration Magic can be a very powerful attribute, but due to its lack of many skills that actually deal damage, you will be forced to utilize other attributes. Inspiration Magic is best suited as a support attribute, keeping the Mesmer alive while other attributes' skills deal the damage. In a party setting, an Inspiration mesmer can be focused on denying their foes energy with the energy-stealing skills, along with Spirit Shackles, while your party members take out the helpless foes.