"This binding allows me basic freedom of movement but I have to attempt to stay within a half mile of you, it's very strict about not letting me mess with you physically in any way so please try not to have a medical emergency or I'll be stuck standing there yelling 'I went to medical school snap the binding' and looking very opportunistic, it lets me make things that are germane to the task we agreed on, which in this case is tutoring - so I can make circles and my computer and notes and references and such, but cannot present you spontaneously with a demonic turtle. I am specifically barred from making a long list of things even if they are germane, including but not limited to very hot and cold temperature ranges, anything inside any non-air non-vacuum medium or within the boundaries of a human body such as in someone's air-filled open mouth, anything more radioactive than a bunch of bananas, any matter that is itself or will when added where I put it tend to form a black hole, etcetera."

"Very thorough. Although it makes sense that limiting your ability to hurt people would also limit your ability to help in the wrong situation." Notes, notes, Cam went to medical school, notes.

"Yup! You can only bind actions, not intentions - if you give me the ability to perform a blood transfusion you also give me the ability to explode you with blood unless you get super complicated about exactly how much blood you expect to be the correct amount for a person to contain, and then you have problems if you want to let me treat children, and you can add more complications for that, but, etcetera. A medical demon circle looks like so -" Slide.

" - wow yeah I'm not gonna try taking notes on that one. General principle makes sense, though."

"I'm glad! So that's the overview on bindings, next is negotiations, do you want to ask any questions before I change topics?"

"I might think of some more later, but no, we can go on to negotiations now."

"So the thing you must be most certain to remember when negotiating is not to accidentally say anything even sort of like 'yes' or 'deal' or 'okay' or even 'mmhm' until you're actually ready to close the deal as described. Negotiation, like binding, runs on natural, even idiomatic, language, and that's terrible, because natural idiomatic language is weird and vague and words serve multiple purposes, and if you're working with a hostile daeva, they will take your 'mmhm' that means 'I understand' and they'll take it to mean 'mmhm' to mean 'go ahead', and there is no higher court to appeal to than 'whatever magic decides that word means with these speakers in this moment'. It does at least use your dialect - daeva get summoners' languages, including dialectical features, when summoned, although if we have preexisting instances of a mutually intelligible language we may use our own accents instead of adopting yours. But your dialect includes homophones and they can get you in trouble."

Notes notes do not say anything affirmative-sounding to possibly hostile daeva. "So it's also really hard to close some deals using language that can't be interpreted in different ways, right? Like - I don't know how you could've done something weird with a deal where you're supposed to create a perfect copy of Morris Freeman's stuffed wallaby, but the first time we met you told me not to ask for just oxygen because it's a fire hazard. I admittedly was not thinking about this when we were all a couple hours from suffocation, but I was thinking about, like - does 'air' guarantee that the mix of gases will contain any oxygen at all? Even 'breathable air' is, like - technically humans can breathe in any combination of gases, just most of them won't sustain us and some of them will poison us. I guess if I specified the specific mixture of gases I wanted, including the correct percentages...?"

"I think breathable air requires oxygen and no poison, in the sense that if I asked if you could breathe chlorine you could accurately reply 'no', but it does admittedly underspecify exact gas mix. If you wanted to be extra careful there, yeah, you'd specify percentages - and whether you meant percentage by mass or volume - and that I shouldn't start with one and then follow up with the others - or you'd have me copy a reference quantity of air, perhaps in a tank."

"Asking demons to copy existing materials seems generally safer, when you can manage it, though I honestly don't know if I could've gotten a tank. Luckily I will probably never have to summon a random demon in a time-sensitive life or death situation again. The language stuff is the part that freaks me out, apart from the thing where the other party is indestructible and capable of wreaking massive havoc if they get loose. I feel like I know just enough about communication to figure that a sufficiently determined hostile actor can interpret things wrong almost no matter what you do."

"It's not hopeless - you can't do, say, mental reservations, those don't work. But a lot of twistiness is fair game, yes."

Notes, notes, at least if Cam is secretly evil he's not the sort of secretly evil that gets her colony arbitrarily blown up. (Probably. Unless he's holding out for blowing up more things on Earth and will settle for the colony if he decides the other option is unlikely to come up, but that sounds unlikely even to her.) "So are there other simple best practices to keep in mind, in addition to not saying anything affirmative-sounding until you're happy with the terms of the deal as described?"

"You also need to bear in mind that you can never compel a daeva to continue. They can always just stop what they're doing in the middle. This is why you're not supposed to travel by bare fairy - a fairy transporting you and some air through space, or even the sky, can just quit at any moment. The shuttles they have that run across Earth on fairy power save fuel and can move a lot faster and smoother and quieter that way, but they can settle safely to the ground or water if the fairy disappears due to summoner mishap or if they just feel like dropping it; and if you have a fairy move a spaceship for you, you need the ability to make a distress signal and hold on long enough for someone to fetch you if the fairy flips you off at any point in your journey. You don't let a medical angel open you up if you don't trust them to close you, too, and you do it in a hospital if you can with human doctors handy. And this is why I mentioned that you could have chosen to specify that I had to make all the gases in the air mix at the same time, because otherwise I could have started with the requisite amount of hydrogen and then stopped. If you don't pay a daeva, their binding stretches to let them hound you for it and you can't get rid of them; there's nothing comparable the other way around."

Notes, notes, she is just going to write this one thing several times because it didn't occur to her and it seems actually extraordinarily important. "But you can't actually go home until the summoner dismisses you or dies, right, otherwise the GCP couldn't trap anyone? But you don't have to be working on a task at any given moment."

"Right. The only way you can be forced to send a daeva home is if you leave them an opening to kill you, which will happen eventually if you don't pay them something you agreed on but can't if you pay - or never agree on a payment. People have kept daeva in their circles, with no task and accordingly no way for the binding to slip, as zoo exhibits - this is now illegal, but I've met a demon who was in a zoo."

"Gosh. So the correct order of business is always have your backup daeva-just-wasn't-feeling-it plan in place, summon, agree on a task, pay for task immediately, and then expect that the daeva will do your thing eventually because eventually they're gonna want to convince you to let them go home." Frown. "Unless maybe you're in a life or death situation with someone you don't know, like - someone summoned a fairy during the leak thing, and they weren't gonna help us because we didn't have anything they wanted. But supposing we had, it'd've made sense in that situation not to pay them until they'd done whatever the specific task was, 'cause if we'd paid them immediately and they were kind of an asshole they could've just sat on the payment and waited for us to die. Being about to die does kind of mess with your options."

"The reasons to pay in advance are if you're not certain you'll be able to cough up sharpish once the task is done, or if the mere fact of being at risk of coercion for the payment would make it worse - the former is why you pay in advance if you're paying in art commissions, the latter's why one pays in advance if paying in sex. In situations where you'll definitely be able to produce the payment, such as a book recommendation or a physical object you have handy, there's much less benefit to paying in advance, and if the daeva actually wants the thing and doesn't care whether you get what you want particularly, they will be more likely to complete your task to get it than they will be to do the task because you paid them first."

Notes notes notes. "Makes sense."

"You can bind a daeva to let you pay in advance, if you're worried that otherwise they'll finish a very quick task and you'll have whatever problem you were hoping to avoid by paying in advance - that clause looks like this -" Slide.

Notes notes notes. Starting to feel like they've been going for a while, but she wants to at least make it through the first slideshow.

"A finished negotiation consists of either the summoner or daeva - for this purpose, either works in the exact same way, interchangeably - proposing a task and payment, in either order interchangeably, and the other party agreeing. It does not work to interrupt the other party with an agreement while they're describing task or payment unless they've actually stopped speaking, forgotten something, and remembered as you utter your agreement."

Nodding and continued note-taking.

"Questions?"

"Not off the top of my head. Possibly approaching the point where more immediate information will lead to worse retention."

"Okay! We can call it a day." Slideshow winks out.