So, for context, my character is still an apprentice. I started playing her almost two years ago as someone who’d gotten into magic fairly recently, knowing a few basic spells. Her progress was very slow during the first year, because I only role-played her once every month or so, but it picked up a lot after I joined my current guild: people are always excited to teach their little group of interns, and also I just play her a lot more nowadays. My answers here have grown organically from there, and are still developing as time goes on.
How does your character approach magic?
- Do they focus on a single discipline or dabble in multiple areas?
So far I’ve stuck fairly close to the WotLK schools of magic. Technically Blitzle is mostly focused on a single discipline, but that discipline is Transmutation which has a lot of facets to it. So I generally feel like she specializes in multiple areas, namely a talent for both telemancy and chronomancy. She’s reasonably good at regular transmutation (turning things into other things), just okay at some of the other schools, and terrible at the rest. Some have just never really come up.
- What drives their specialization (or lack thereof)?
The two main specialities happened just because I think they’re neat. Teleportation is cool, Time magic is cool. In character, Blitzle just sort of has a knack for them, influenced a little bit by a magic item she obtained (stole). Teleportation especially ties in to what magic means to her: a sense of freedom and self-determination that she sorely lacked before getting to Dalaran. One day she hopes to be able to teleport wherever she wants, what’s more free than that?
A lot of her other skills (or lack thereof) came from rolls during teaching RP, which I then tried to make sense of after the fact. She tried to specialize in enchanting for a few months (because flying weapons are cool), but her rolls just wouldn’t back it up. I interpret it as her being so used to turning things into other things that it’s difficult to wrap her head around adding a layer of magic onto things while the thing itself stays the same. It’s too subtle a difference.
How do you balance your magic user’s power level?
- What limitations do you set to avoid making them feel all-powerful?
First of all, because of her relative lack of experience, Blitzle’s spells just lack oomph. She can toss a frostbolt or conjure an ice barrier, but they just don’t hit as well as those of a full-fledged mage do.
Second, there are a few schools that she just hasn’t studied much. Never tried much divination, conjuration, or illusion, so she’s pretty inflexible there. And while she casts a fair bit of evocation and abjuration (because DMs love to include combat in their events), it’s never come up much during her IC lessons, so she hasn’t developed much in those fields since I created her.
Then more specifically, she’s deathly afraid of fire, has never been able to create any of it, and I doubt she ever will.
Finally, I think she has some degree of aphantasia. This first came up during telemancy lessons, where she was really good (i.e. rolled really well) at teleporting to places she could see, but did much worse teleporting to places she couldn’t. Had trouble visualizing them. That stuck with me as she went on. She’s since learned to teleport to the mage quarters of different cities, where I like to imagine they have some kind of… sequence or pattern inscribed in a circle somewhere, unique to that place, and so very difficult to imagine wrong when she looks it up in her spellbook. But she’s never been able to teleport anywhere that isn’t specifically set up for it, even places she knows quite well.
It’s snuck into some of her other studies as well. She’s good at polymorphing but had a lot of trouble turning someone into a duck, because she’d never seen one and could hardly imagine them from illustrations alone. In the future, she’ll probably have trouble conjuring novel things as well, and will be terrible at illusions when she finally gets started with them.
- How do you engage in roleplay without always having the perfect solution?
She just doesn’t! 
I keep track of the spells she’s learned, so if a spell isn’t on the list, she (usually) just can’t do it. For example, during the recent Undermine events she was part of a mage squad tasked with keeping civilians safe through shield magic. She could help out easily enough while others cast spells like that, but then the group split and she just… couldn’t. Didn’t know how. The best she could do was conjure an ice barrier around just herself, and stand in front of people. It led to a lot of frustration on her end!