"That makes sense! But if I test an explosive bullet against a fire elemental and its own body doesn't entirely contain the explosion then it will affect the surroundings, at least cosmetically. And I think it's not really possible to perfectly guarantee that a cave or building won't collapse because of an explosion in just the wrong place, if the building isn't explicitly designed for that or the cave has never been stress-tested that way. If we need to do it, I'll start small and scale up slowly to mitigate the risk, but the downside is that this will use up many bullets and possibly also many fire elementals."

"I would much rather avoid explosions underground, but if you think we might encounter fire elementals or other creatures apparently invulnerable to light and heat then I think we ought to test it. In real combat I'll use light or heat on any target vulnerable to those, and I'll check if the fire elemental is vulnerable to light before I explode it. I can also just shoot many non-explosive bullets but I'd be using up my supply very quickly and I don't want to do that for a test."

"Does your method of putting bullets in things not also work on, like, rocks? Putting a rock through an elemental will also hurt it."

"I shoot bullets from my rifle. The bullets have a small amount of explosives that when ignited propels them through the barrel." She demonstrates with an exploded diagram illusion. "And I can add spells to the bullet on top of that. I... suppose I could push rocks with my flight spell," like a primitive caveman desperate soldier out of ammunition? This would be a useless tactic for aerial mages who can fall back on optical spells anyway, but at close quarters... hmm. Tanya does some quick calculations. "My spell is optimized for applying force to relatively large objects relatively slowly, and is very bad at propelling even small rocks when you need to apply the force very quickly. It probably wouldn't be competitive with a crossbow, let alone with real bullets. Larger rocks might work better; they won't penetrate but they could bruise or even crush someone if this works out. This might be a good idea in some scenarios and is definitely worth testing."

"I'll need rocks of various sizes, from a pebble up to say fist-sized, ideally hard ones which won't themselves fall apart when force is applied to them so I can reuse them and experiment for a while. Something like river-rounded stones would be good, although aerodynamics probably doesn't matter much at this scale. And a cave where I can magically throw them at the wall, since I assume you have no cheap disposable targets made from wood or similar. This isn't a standard use of the spell so I want some time to practice before proceeding to live targets."

"Yeah no absolutely nothing made of wood is cheap or disposable. We can go down to the river and get some rocks."

"Oh, you do have a river, I'd been wondering about your water and sanitation situation. ...I mentioned that I can boil large quantities of water quickly and cheaply, if that's helpful for anything." Presumably they don't want their river boiled but maybe they want a big hot swimming pool or something. The river itself could be used as a backstop that won't get scratched although she won't be able to reuse her ammunition; it might still work out if the riverbank is full of suitable rocks.

"The river is relevant to the water situation because it's cheaper than going to the temple but it is not really relevant to sanitation. Do you want me to Prestidigitate you clean?"

It makes sense for the temple to charge for entry to its public baths, or drinking and cooking water if it has any piped in or filtered. Pity how it's the temple that's doing it and not free private enterprise. "I meant for disposing of sewerage but - I suppose belowground you'd use it all for manure? And for baths, yes. What is Prestidigitate?

"Yeah, nightsoil all gets sold to farms. Prestidigitation is the most versatile cantrip, it can clean things including people and their clothes, if desired while you're still wearing them though that's not how a high throughput business will do it."

How would you clean clothes while worn? A spell could direct water and then air easily enough, but that sounds uncomfortable for the person wearing the clothes and liable to leave you either moist or too warm, and some detergents might not be great for your skin. Maybe the spell is extremely precise and flexible to allow it, but why would someone bother developing such a spell when cleaning clothes not being worn is so much easier? Anyway, that's not important right now. Tanya does not particularly need her clothes cleaned if she doesn't have an opportunity to get herself cleaned, which she would appreciate but is also not a terribly high priority. She might ask for a bath at some point, but these people probably don't have private paths and a public one would draw attention to her orb and weapons because she has to keep them close at hand. In the worst case, she can take a dip in the river.

...she gives herself a mental shake. "Thank you, but that's not necessary right now." Does Belmarniss have time to answer other questions or does she need to teach her class soon?

The girls are starting to trickle in and pay for their lesson! Niss explains Tanya to the kids as a human adventurer she's been toting around who may listen in on the lesson because her magic is from far away and works differently, and then they are talking about the cantrip Message.

Tanya listens attentively. It's important to learn how local magic works, even if she's not going to learn how to cast it. And Message has obvious tactical applications.

It sure does! This particular classful has all gotten it scribed into their books in a previous session but they're still new to it and need more familiarity with how it handles so that they don't drop it when they cast it and that's what Belmarniss is doing, answering questions about why it squidges this way and which parts you need to be most careful with and whether you should fling it like this or like that.

Tanya can see the magic they're handling and she can maybe if she squints convince herself that she sees a correspondence between the magic and the shapes they're describing and have drawn in their books, but she has no idea how to even approach manipulating magic like this. Really, it's quite regrettable that this amazing opportunity for cross-fertilization between two completely independent magical technologies has been wasted on a soldier like her.

One of the kids has fallen into a two-handed casting habit and Belmarniss puts her to drilling subcomponents of the gesture! One kid keeps dropping her copper wire when she gestures and needs to drill that! One has it pretty much down and is poking the other students with Touch of Fatigue and Belmarniss Mage Hands the disruptive kid's hood down over her face before she can grab the next one and assigns her to go over there and receive longer-distance Messages. As more and more of the girls get the cantrip down they wind up scattered about, practicing.

These other simple spells also make sense, both as things that are simple to do with magic and as useful applications of it, and the use of 'foci' (casting implements) is also familiar. The gestures aren't and she really doesn't see why you can't just skip them? You need to shape the magic right  but you do that with your mind, what do your hands have to do with it?

Prepared spells are also new. She doesn't detect any magic while the spell is being 'prepared' or while it's apparently hanging around ready for use, so what is actually being done? If it was just mental preparation or calculations, they wouldn't need to redo it every time... She'll ask Belmarniss later, although she might not know either. Still, while interesting it's not obviously decision-relevant.

Class lasts almost two hours and then the girls mostly disperse.

(Is the class gender-segregated?)

Tanya is ready for whatever is next. If she has to figure out a way to hurl rocks to bludgeon animals, that is objectively very silly but a soldier does not pass up any opportunity for an advantage.

"You want the fire elemental here or by the river so you can try the rock thing?"

"I want some time to practice with rocks first. But the river might be better anyway if people won't care if I scratch the cavern walls, and if I angle my shots down the water itself can provide a backstop."

"Scratching them is fine, yeah."

"Unless the river is very shallow, I expect I can practice with rocks in a way that flings them into the water without any collateral damage. I don't know what explosions underground will do and will be as cautious as I can, and I don't know if the cavern the river is in is any more fragile than this place. Generally speaking, explosions have more force the smaller the space is and narrow tunnels would be at most risk of collapse. If I'm shooting explosives at a target on the ground then at the ground under and around it is at risk of breaking, even in an open space." That's just how explosives are!

"If the goal is for you to see my light-based attacks, against a target vulnerable to those, we can do it most anywhere because I can ramp them up gradually and rock can generally absorb a lot of heat, but water can absorb even more so the river would work for that too. If the goal is to test explosives, specifically, then there's some risk involved. If it's to test blunt projectile damage, I don't want to spend more than a couple of bullets just to demonstrate but I can practice with the rocks first and see if that amounts to anything. How many times can you summon targets? And how far away is the river?"

"I don't think we need to test explosives specifically; at no point in the trip upstairs are we going to be assured of a battleground that isn't a small to medium sized cave. The riverfront area I have in mind is about a half hour walk, and I've got two summonses today and room for a couple more little ones if we want them."

"Then if you have the time, I could practice with rocks and then test them on a fire elemental, and separately test optics on a different kind of target. Or I suppose you could leave me at the river for a few hours and come back."

"There might be people fishing there, I'd sooner stick around."

"That makes sense. Shall we head there? ...My practice would probably scare away any fish; maybe we could move up or downriver."