Hmmm, I seem to have missed that agreement within narrative confinement thing.
I will tell them ICly beforehand that she will run the instant it goes physical.

Here is the situation in a nutshell:
What has happened:
Aaron Cohen, sculptor with More Ambition Than Skill or Sense has found in his old family houses attic the Tome of MaHaRaL, item of power that grants Thaumaturgy and a stunt to use craftmanship instead of lore for thaumaturgy. At first not believing what was written there but still curious started reading and in the end managed to summon Merida, a lesser fae and a muse. He bargained and agreed to give "year and a day of his life" in exchange for being famous.
I gave her Incite Emotion(Lasting):Inspiration to represent her ability affect peoples minds. Consequences like "Fevered inspiration", "Compulsive painting/sculpting/whatever" and the like. She creates those, manouvers to gain more tags and gives some to him and uses some to comple him to do more. Quality and crafmanship of his works improved vastly over short time and people started to take notice.
Then he found out that what she meant to do was to compel him to make couple masterpieces and just as he was going big take him away to Nevernever. Artist that previously was moderate at best suddenly makes, in a short amount of time, lots and lots of very high quality stuff and then vanishes without a traces after completing masterpieces? Sure he will be known and famous. But "year and a day of his life" in Nevernever is going to be much longer in our world. He wont be able to enjoy being famous. After all she has "Beware what you wish for".

He panics and uses the tome and one of his sculptures to create golem, to try to stop from taking him away. He has no fighting skills at all so he cant really do that himself. He refuses to let her in and basically locks himself in his, now warded, house. Him and her are in a stalemate. Unfortunately his control of golem is not that good and he mumbles in his sleep. Nonsentient golem takes scared mumblings as order and leaves house to beat whoever it comes accross.

What the PCs know: Someone has been beating apparently random people, including their allies, friends and contacts and they have been asked to help.

IfWhen they talk to Aaron they will hear that she does not fight and will flee at the first sign of violence. She will always negotiate and is true to her word, exacly her word, no more and no less.
The first time they'll meet her is probably just outside his house. He'll do the name and little will summoning. I understand it is basically like sending a "come here please" textmessage which doesnt force her but gets her attention. He'll then retreat to house and refuse to speak to her.
So she will be unprepared for PCs at the first meeting only. After that it will probably be in a park(she is summer), midday/afternoon with a lot people having picknic, walking dog etc. To discourage fighting.

She'll at first ask them to steal a specific letter that is protected by strong threshold and very little else. No monetary value but huge emotional value to its owners. Stealing from elderly widow that one of the PCs know, a precious love letter from her deceaced husband? That should make them at least hesitate a bit. Of cource they might not know about this beforehand, depending on the negotiations
In exchange for even to consider negotiations for fine tuning Aarons time spent away. In exchange for that she want a favour from them, to be collected later.

Ways they could solve it that I can think of:
*Do as she wants, have Aaron be gone for year and a day and not much more, owe her one favour. Gain possible ally and I can use that favour for plot later.
*Manouver smartly and corner her in a fight. Force her to keep him only that year and a day. Gain possible ally and enemy.
*As above but force her to end the deal with Aaron completely. As he is not famous yet neither has fulfilled their end so it might be possible to break it. He looses his skills and interest wanes. He still has the tome and might try something else later. She might hold a grudge for a while.
*Do nothing. When Aaron eventually returns he will be somewhat pissed about that. Gain enemy at much later point. Maybe only a small complication by them, but at suitable point that can be enough to make things interesting.
*They think of something of complete different and I will roll with it. Will be interesting.

PCs are strong in physical conflicts and she is strong in social conflicts. Unless she bring a lot of backup she will loose straight fight and probably win negotations unless players seriously outmanouver her and use those fate points. She will be at 3 vs 1 in social so it is possible for players to manouver around her even though their social skills are much lower than hers.
About that is there way to balance different numbers per side other than lesser side having much higher skills?

This will be the first scenarion of the campaing and only I am familiar with DF world. Point is to intruduce the world and the system. Physical conflict(golem fight), conceding(golem will concede), social combat(first negotation), freedom of choice and I will roll with it(what ever comes after first meeting her). Also supernaturals are individually almost always stronger than mortals, so play smart and know what you are up against. Sometimes there is no easy solution.

  That is way more text that I though it would be.

Hello

Can conflict end in other ways than one side taken out or conceding?

In my upcoming game there is following situation:
NPC who is good socially but not much physical conflict ability. She'll want to talk PC around. She has Inhuman Speed and Glamours. If PC decide to physically attack, she most likely goes first, because no PC has speed power. Can she just Glamour herself invisible and move 1 zone free thanks to power and unless PCs manage to find and stop her just sprint away in the next exchange?

No one is taken out, no one concedes but conflict cant really continue if only one side remains.
I'd think this is possible but I got the impression from books that conflict should end with either taken out or conceding.

What would you say to "If Conviction > Threshold, then +2; if Conviction =< Threshold, then +1"? That gives it an actual effect no matter how high the threshold is.

I thought about doing it this way too.

Uh...they talk about this, with the power of the threshold reducing shifts of effectiveness. Which seems right-ish. I might have them reduce Refresh worth of powers instead if house-ruling...

Hmm.. Maybe reduce refresh worth powers, starting from the most "aggressive". Strenght goes first, dunno after that.

Hmmm. That's not an invitation...but your obligation to the Faerie (and the stab your own hand type stuff) would ignore the threshold. This is a personal opinion not based on any rule directly.

So in your opinion if character and fae can communicate, for example through open window/door, and are different side of threshold the fae could order character to do something embarrasing and/or nasty, but not really come in?

Yes, that's correct. They have to actually consider it, but they don't have to agree.

In character, remember that Fae tend to be picky about favors being exchanged for equal value (though the "valuation" calculation can be extremely subjective).

Oh she will. From her perspective it will be sure, gradual power or the ace in the sleeve of having characters owing her.

I'm...not sure that's valid. They'd all have to knowingly agree for that to be binding. I mean, one of them agreeing and the rest all thinking it just applies to that guy won't bind the others. There's also no reason for the Faerie to be less than clear on this. People who owe you are only useful inasmuch as they know they owe you.

Just a note, in my native language singular and plural you are completely different words. Still, dunno what to do with this. Might give them roll so notice or compel not to notice.
Settings wise, I feel that if they go to negotiate with a fae without preparing for trickery and knowing to be precise, they should be somewhat tricked. She does have aspect "Beware what you wish for".
Of course I will tell them to first find out who/what they are facing and what they should expect. And they will know that the previous person they know that negotiated with her got badly over his head.

That's...all really shaky. Trading the favor away to someone who's dangerous is asking something dangerous of them, and the Fae would have to use their actual judgment as to whether the favor was dangerous. Ordering is also bullshit, either they can't order them at all, only ask and have things granted, or they can't order them into anything dangerous...those are the only ways I can think of the wording working out. No, what you should have them do if they need a dangerous favor is much simpler: "Bring me three children to devour." That's not dangerous, just horribly immoral, after all...then have them blackmail the PCs with the promise of not asking anything immoral of them. Possibly gaining two favors for the price of one.

Out of character, consider the opinion of the NPC Fae that you want to inspire in your players.  If your players feel that they got bent over a barrel in the negotiations process while making a reasonable effort to be competent, this will likely inspire hard feelings and a disinclination to negotiate in the future.  (Yes, if the players actually screw up--and know they screwed up--there should be some pain, but this should be balanced by making sure the story has some resolvable path.  "On rails" is bad.  "No conceivable successful outcome" is worse.)

Be careful about employing seriously aggressive word-lawyering on your players.  It's like spice; some is good to get the proper Fae flavor across, but people don't generally dig in to a heaping pile of curry powder.

Yeah, I am dropping this. Severely limiting those favours could be a concession if she fails negotiations. Otherwise she will give no promises about them. In that case trading them away is a possibility.
Bit related to that, is it possible to do social attack against more than one person at a time? Like spray or zonewide. Does that even makes sense?

Have the difference in perspective work to their advantage some, too. If they help the Faerie without some deal in place, have them show up later and save their asses, noting that the debt is paid. Stuff like that.

Very good idea, thanks.

Sometimes it's more fun that way.

Probably yeah. Might get interesting when creatures aren't what they expect.
"One zombie? Phew that is so eas... Did that thing just run through wall without slowing down?!"

I know in Ghost Story, it was noted that the White Court Vampire that walked into Murphy's house (which has a decent threshold) left almost all of her power at the door, so I think the above could work.

As for owing the favour, something like this was mentioned in Cold Days, specifically

(click to show/hide)

when it was noted Cat Sith could enter a threshold uninvited for benign, good, or unharmful reasons, but if he wished to kill someone, he would be unable to do so due to the threshold

. You should also note that when Mab did her little harassment of Harry, he was in his office, not his home, so she was exempt from this rule.

I had forgotten these, thanks.
So if denied, the fairy would leave, but could wait outside for the moment they go outside threshold and then do that or something similar.

Finally, True Faith is probably the exception to the rule, as it tends to almost ALWAYS be the exception, especially considering that it cannot worth when acting against your faith. So if you are in the home of an Evil Warlock, uninvited, you could probably let loose with your Faith Powers as long as you were trying to stop the Warlock from harming someone (and not using your powers to steal, for example).

Hmm, intent matters. Going for selfless and/or general good reasons and they work. Going for no particular or selflish reasons and they dont.

This whole section is a can of worms waiting to happen.

I know, thats why I am thinking what would be storywise interesting but not dicking over players.

For example, for your first note, the Sidhe would be required to perform that favour, but that may not be done EXACTLY as expected...and they would probably do something to ensure that whatever they were asking for would be "required" anyway (like Mab in Summer Knight).

Maybe I wasnt clear. Fairy is asking them to do something before she is willing to negotiate on a bigger thing.

For your second, it could be taken as a favour from each one...or a mass favour that they all have to participate in. In fact, when one of those fae is asked for a favour, the whole mess of them could show up and make things much more complicated than expected.

This last one is all lawyer~ish. Negotiation is normal, but it is something to look out for.

Maybe. The whole point of scenario would be that that fairy has tricked an NPC to very unfavourable deal and negotiating with her is one possible solution to situation.
If/when negotiating start they would already know that she is tricky and will try to squeeze out as much as possible.

When it comes to using the Sidhe, I have YET to see a GM not be a dick to get that point across.

I know that is why I want to be careful.
My group is quite mature, if the situation makes a good story people wont mind little screwing over characters. I just have to make the following situations interesting and fun.

Isn't that usually the case?

Most often yes.

How about going the simplest possible way:
As Item of Power character has relevant aspect. Compel that charges run out when dramatically appropriate.
Similar to weapons needing reloading. No rebate but FP when it comes up.

Official rules have to have some semblance of game balance.
Each group is free to modify rules how they see fit. Personally I prefer to paly first with rules as written and see if there is something that needs to be modified.

The most important rules I know are 2 variants of rule zero: Thou shalt have fun and when rules get in the way of the story, ignore rules and tell the story.

I feel that. I think my roll distribution is about a triangle. Fail often and rarely get above average rolls. There was one session where I was completely unable to roll below 80 on a d100. (lower was better, 96+ autofail).
Then all that came back once when I rolled about half of my rolls as crits. With 10% crit chance

But back to topic. There is that magic system toolkit coming soon, maybe there are something similar or reworked DF style magic.