"It can handle three? Yeah, let's do that. Rituals cannot be conducted over osanwë?"

"It'll be slower and colder, but it'll stay in the air.

Doing rituals over osanwë hasn't been tested, obviously. But I wouldn't expect it to work. Voice matters for a lot of them, and it wouldn't work in writing."

"Okay. Slower and colder is fine. Is this the one for which amplifying our voice would matter?"

"No, this is just the preliminary step of making you practitioners at all.

The liquid non-sphere touches down and keeps its shape as they exit.

You will each need a personal item, too, along with the standardized pieces. Doesn't really matter what so long as it means something to you.

Something - positive?

Just something important.

Okay.

They bring all of the items back with them a short time later.

Is there any place in particular to aim for, or just far enough away?

You're the one who'd know, I expect.

Guess that's a no.

She heads in a direction. It's pretty monolithically unremarkable out here, magically speaking, so just distance.

And then they land.

"We want to imitate this shape," she shows the Eldar a page displaying a diagram and (English) text. "I'll start describing the small print while we set up."

And they get to work. Your letters are very neat, he says, impressed. 

Not my letters. We use printing- actually, that's not even printing. That reader's electronic. Has quite a few books on it, including the few magic books I've managed to get converted. The screen swaps to the text said during the ritual, then back. The letters stay perfectly regular.

"The most important warning label about this ritual is that once you're a practitioner you can't lie. If you do, you lose magic power, karma, and physical strength. You might recover in a week or two from a sarcastic comment with few witnesses. Failing to keep a promise to allies who relied on you would take longer, and a voluntarily broken oath can be permanent. Not that I expect it to come up much, but being forsworn is usually considered a fate worse than death so I really should emphasize it. You'd lose all protections against Others, all ability to use magic, and eventually you fade from the world entirely. Literal unvarnished truth is good, when you must mislead people do it by saying irrelevant true things.

Aside from that, most of the rules are based on an idea of fairness. If you accept something from someone else, and it wasn't clear that it was a free gift, you owe them. Debts don't have to be repaid exactly but they do have to be repaid eventually. 
Never be the first aggressor if you can avoid it. If you can't avoid it, dramatically talk to an empty room about how they've wronged you even if you have to exaggerate. The spirits are gullible sometimes, which isn't a great quality in a judge but it's not their fault they aren't sentient.

Other rules are based on hospitality. If you have a visitor, you offer food and drink. It's from a time where places to stay along the road were few and far between, and turning away a traveler might mean they die. If you're a visitor, you don't exploit that because you might be dooming the next one. None of the reasoning is true anymore, but it stuck around. You don't betray people after offering or accepting hospitality, even if you are enemies who would otherwise kill each other by any means.

And then there's the discriminatory ones. Individuals don't matter. The basic unit is the genealogy, and the members are only relevant because the family acts through them. Since you two will count as separate bloodlines this won't affect anything yet, but if there are ever sequential heads of the same house they're interchangeable as far as magic is concerned. This does also mean people can be partially liable for the actions of their descendants, and of course the descendants can inherit the family name.

Oh, and the universe is pretty inept at finding who to blame for things. Leaving an enemy in a near-certainly fatal trap is not murder, by these rules, because you didn't deal the blow. In general, any sufficiently indirect action can fool the universe.

By becoming a practitioner, you agree not to chase after or antagonize any Others that have agreed not to prey on bystanders. That's most of the sentient Others, especially the older ones. That shouldn't come up much either, but completeness.

They both nod solemnly. Findekáno looks bitterly lost in thought, but then he draws his attention back to the instructions. "Understood."

"I've mentioned that many Others are by default hostile. There aren't usually a lot of those in historically uninhabited places like here, but if and when you run across some they will be free to attack you if they think they can get away with it. Some are. Harder to deal with than others.

Even the hostile ones usually don't do anything, because practitioners tend to be in groups and if they strike against a family the family might strike back, but there are very few practitioners here. There'd be less power or recklessness required for something to decide to- come after you.

And with that I think I'm finally out of bad news."

"If someone becomes a practitioner, swears an Oath, breaks it and kills themselves, by our laws that's as far as the Oath can reach them until they return from Mandos. By yours, it affects their dsecendants?"

"Depends on what they swore. If they say that it affects only them that's true.

Otherwise, the karma lands on their descendants, the descendants lose the power benefit of having a bloodline behind them, but they don't automatically become forsworn. Unless the original oath was sworn on their blood specifically, in which case it can affect their descendants as much as it affects them. Oaths are a very bad idea.

Wait, you can return from your afterlife?"

"Oaths are a spectacularly bad idea," he agrees firmly. "Do ones sworn before you become a practitioner count in this sense? Not that we didn't have enough reasons to keep my cousins away from your magic.

And no, we can't, because the Valar are really angry with us. In theory since we're supposed to be undying if we die we get sent right back."

"Um. Wow. I guess I shouldn't be surprised by species differences by now, and yet. When you say laws, are you talking about the regular government-jurisdiction laws that wouldn't reach into most afterlives anyway?

Oaths from before don't count, or they barely count the same way everything else a normal person does barely counts. But if you previously took an oath and you reaffirm that you're going to keep the oath then it does. Even saying you took the oath is dangerous, since it relies on the spirits noticing that this oath was from before. Not a distinction you want to stake anything important on."

"If this gets anywhere near my cousins the whole continent will probably die an extremely bloody and protracted death."

Irissë nods. 

"And I just mean the laws that govern Oaths for non-practitioners."

"For non-practitioners where I'm from, an oath is just an unusually serious promise. No law involved."

"That's very odd. A voluntarily broken oath is a fate worse than death for us anyway."

"Huh. Guess I could have eased up on the dire warnings. What counts as an oath here? If it doesn't happen to be the same, there's a risk of accidental swearing."

"You have to say it explicitly. 'I swear', or 'we swear', or 'I hereby pledge' or something. Usually people embellish but you don't have to. The Oath my cousins swore - oh, we don't share a writing system, I don't know how to communicate it to you safely."

"That sounds mostly similar. For a practitioner's oath, just explicitly promising is enough but embellishing makes it more powerful. Partly because the spirits like dramatic things and mostly because if you swear by something there's something specific on the line. Our kind does work in writing, or presumably osanwë; what matters is that you send the message. You could swear an oath through flower arrangements if you and the person you're talking to had a specific enough code.

The reason people swear at all is that it makes you stronger—both magically and physically—while you work to fulfill it. Sometimes the boost is too tempting to pass up. You also get plenty of good karma if you succeed, but people taking this risk aren't usually weighing the long-term pros and cons."

"In that case, is there a safe way for me to communicate to you the content of my cousin's oath? The spirits, ah, would stand up and pay attention, and it'll be really really bad -"