is there a mechanic for making bargains?

[Amseriah]

Just like the topic said.  Is there a preexisting mechanic or has anyone houseruled one?  I was wanting to know about fae and human contracts primarily.

[luminos]

I'd handle it with aspects.  Without a bargain, the fae would be self-compelling a lot to avoid interfering directly in mortal affairs.  With the bargain, the fae can do whatever it wants to the person it bargained with until the bargained is fulfilled without having the auto-self-compel come into action.  I'd probably give the mortal a temp aspect for the bargain as well.

[WillH]

In a way it is. Sidhe lords have no free will (refresh) and are ruled entirely by their nature. If they make a bargain they must abide by it. Mechanically, they have no way of resisting a compel forcing them to follow the terms of the agreement. On the player's side, if the break the deal, they would allow the faery to act directly against them, because it's now within their nature to do so. That could be very hazardous to their health.

[admiralducksauce]

The actual making and binding of contracts sounds like concessions and consequences (possibly a Taken Out) from getting into social combat with the sidhe to me.

[Becq]

You might also look into the 'debt' rules that are discussed along with sponsored magic, if you need a mechanic for a bargain 'currency'.

[sinker]

Yeah, I was going to tell you to go look at debt too (YS288-289) sponsored magic overall is a pretty good reference (even if they don't want magic). If you really wanted to go all out though you could have the PC change one of their aspects to reflect the deal.

[Drashna]

Check out YS274.  There is a big ol' box about "Oaths, Bonds and Bargains".  Worth reading.

Though if the bargain is for magical power, Sponsored Magic is definitely the way.
Though if you don't want to go that route, I'd say create a power that allows you to "invoke" the power like an aspect but with anything in regards to the said deal, with no fate point expenditure, but instead it creates a point of debt that can be compelled by your sponsor.  Very much similar to Sponsored Magic.

[Ryan_Singer]

A quick note the player should keep in mind: Sponsor-debt compels can really suck, and eventually, you will face some while out of fate points. It's a matter of time.