Guild Wars 2 has special mechanics for its classes. I have no idea how they work and have no idea where in-game would explain it. I assume the wiki has some information. I also assume that there will be more information available somewhere, sometime, but that it felt suboptimal to implement that while major changes to those mechanics are underway.
I tried two new classes for the last BWE, Mesmer and Thief. I knew that Mesmer abilities revolved around clones and confusion. Okay, first fight, I have just my basic attack, here we go. Bam, bam, why is there a clone of my by the enemy? There’s another one. Oh, they’re gone. Trying that out of a few fights, my basic power was flipping between three different versions faster than I could read the text on what it was doing. Oh, so those little lights indicate how many clones I have out. I’m not entirely sure what the clones do beyond what it says (use one attack).
The Thief comes with a Steal ability, which picks up an ability from the target. That will involve learning some icons to make full use of it. Thieves stole the GW1 Assassins’ shadowstep, and they have Initiative dots. Initiative is … I don’t know. It looks like an energy system of sorts, because I at one point did not have enough initiative to throw a dagger. Skimming the forums, it looks like they’re mid-revamp (or maybe just balancing heavily), so it seems unprofitable to learn much now. Having played only a few levels, it only mattered once, and it mattered by stopping me from doing what I was doing. I presume it matters more later.
Part of a GW2 training area will need to be an explanation of what your class mechanics are doing. Maybe that comes later in life. I was only getting to Engineer kits on the first character I tried, and the Elementalist’s element swapping is intuitive once you notice the icons. I haven’t even looked at half the classes, so I may have quite a bit to muddle through. I can see level 20 players in groups saying, “Is that what that does?” for the next two years.