First of all: What are Mesmers, exactly?
In as few words as possible the Mesmer is an Arcane Trickster, my single favorite class description of all time. It gets right to the point. They're not Elementalists, or Mages but they are magic users. At the same time they're also deceivers intent on causing confusion and misdirection. They do damage, but not directly. They have plenty of hexes, but usually the hex comes with a caveat. Something like, the hex will only work if your foe performs and action, or doesn't, or whatever. Though their amazing interrupts and energy denial made them a staple in the PvP format. You can, of course, make a Mesmer revolve around doing direct spike damage and that furthered their roles in structured PvP, but even the Mesmer spike relied on your target having energy to deal it's damage. If your target could hide their energy then most of the spike tended to fall short.
Mesmers: Tyria's Neglected Child.
All these factors served to increase the confusion of "why bring a Mesmer" specifically in a PvE situation it didn't make sense to bring a character who could only deal damage under certain circumstances. Even with all their usefulness the Mesmer tended to be very contextual. Mesmers were a class that was complex by nature and the massive pool ArenaNet had developed with their skill system (1319 total skills to be exact, of which a player could use any 8 from 2 different professions. Giving them anywhere from 222 to 281 skills to pick from at any given them) only worked to compound this complexity. Furthermore there wasn't typically something that a Mesmer could do that another class couldn't also do. After all, with the secondary class system anyone could take a Mesmer skill if they wanted. And in PvE, when the goal is to kill mobs as quickly as possible, people usually just went for the damage. It just made more sense.
You tank the mob, you heal the tank, you kill the mob.
A Mesmer was a big question mark in that equation. On their own, were too niche to handily fit into the standard Holy Trinity template. They were great for soloing, and specific builds, but general PvE didn't have a place to fit them in. Mesmers were almost too specific of a class.
If you're interested in some deeper reading on the Mesmer's lack of a role in PvE I suggest this post, it's quite lengthy but it goes into great detail on the issue.
Introducing ... Hard Mode.
Turn the clocks forward to the Hard Mode update. The days of Normal Mode and mass nuking were over. Previously all that the party needed was tanking, healing, and damage. They could clump up the mobs and decimate them all in one swoop. Elementalists were great at that. The introduction of Hard Mode improved monster AI dramatically, and increased their health and damage. Packs of mobs no longer stayed clumped up under meteor storms. They would scatter and avoid damage. Nuking, in the old sense, was no now impossible.
The group now needed a way to control the mobs as well, mitigate damage, reduce their healing, and shut them down. So much so that if you're going to run any Hard Mode PvE content today you'll always want to consider including Mesmers. It turns out that the way most Mesmer abilities worked made them perfectly suited to exploit Hard Mode and the mobs' increased attack speed and altered AI. Since Mesmers had always done damage best whenever mobs performed actions, now that they were performing actions 33% faster it meant that the mobs were actually now killing themselves 33% faster as well. It became a perfect situation for Mesmers to flourish. Then take into account Mesmer's amazing interrupts, they became crucial to killing any mob that had a lot of healing potential. The Mesmer could shut down the healer and the rest of the group could do their job and finish off the pack.
That's where it turns out the Mesmer fit in after all, by controlling how and when their foes perform actions. When you can't act, you can't fight, and when you can't fight, you die.
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I hope you enjoyed this short lesson on Mesmers. In the next part I'll be looking at the new Mesmer and how she fits into the Guild Wars 2 universe.
