When you have leverage on a GM Character and manipulate them, roll+Cha. Leverage is something they need or want. ✴On a 10+, they do what you ask if you first promise what they ask of you. ✴On a 7–9, they will do what you ask, but need some concrete assurance of your promise, right now.
Parley covers a lot of ground including old standbys like intimidation and diplomacy. You know you’re using parley when you’re trying to get someone to do something for you by holding a promise or threat over them. Your leverage can be nasty or nice, the tone doesn’t matter.
Merely asking someone politely isn’t parleying. That’s just talking. You say, “Can I have that magic sword?” and Sir Telric says, “Hell no, this is my blade, my father forged it and my mother enchanted it” and that’s that. To parley, you have to have leverage. Leverage is anything that could lure the target of your parley to do something for you. Maybe it’s something they want or something they don’t want you to do. Like a sack of gold. Or punching them in the face. What counts as leverage depends on the people involved and the request being made. Threaten a lone goblin with death and you have leverage. Threaten a goblin backed up by his gang with death and he might think he’s better off in a fight.
On a 7+ they ask you for something related to whatever leverage you have. If your leverage is that you’re standing before them sharpening your knife and insinuating about how much you’d like to shank them with it they might ask you to let them go. If your leverage is your position in court above them they might ask for a favor.
Whatever they ask for, on a 10+, you just have to promise it clearly and unambiguously. On a 7–9, that’s not enough: you also have to give them some assurance, right now, before they do what you want. If you promise that you’ll ensure their safety from the wolves if they do what you want and you roll a 7–9 they won’t do their part until you bring a fresh wolf pelt to prove you can do it, for example. It’s worth noting that you don’t actually have to keep your promise. Whether you’ll follow up or not, well, that’s up to you. Of course breaking promises leads to problems. People don’t take kindly to oath-breakers and aren’t likely to deal with them in the future.
In some cases when you state what you want you may include a possible promise for the creature to make, as in “flee and I’ll let you live.” It’s up to the target of the parley if that’s the promise they want or if they have something else in mind. They can say “yes, let me live and I’ll go” (with assurances, if you rolled a 7–9) or “promise me you won’t follow me.”
Leena: “Lord Hywn, I need you to vouch for me or the Queen will never grant me an audience.”
GM: He’s not really convinced—it could be a big hit to his reputation if you embarrass him. “Why should I help you, Leena?”
Leena: Oh, while I talk to him, I absentmindedly play with the signet ring from that assassin we killed. The one he hired to off the prince. I make sure he sees it.
GM: Oh boy, okay. Roll parley.
Leena: An 8.
GM: “Enough being coy!” he looks at you cold and angry. “You and I both know you murdered my hired man. Give me the ring, swear to silence, and I’ll do as you ask.”
Leena: I toss it to him. We can always dig up more dirt on this scumbag later.
Pendrell: This is the place where One Eye plays cards, right? Okay, I walk up to the guard. “Hey there fellows, care to, you know, open the door and let me in?” and I’m being all suave and cool so they’ll do it. Parley is roll+Cha right?
GM: Not so fast, slick. All you’ve done is say what you want. The big smelly one on the right steps in front of you and says, “Sorry sir, private game,” all bored-sounding. It’s like he hates his job and wishes he were someplace else. If you want to parley, you’re going to need some leverage. Maybe a bribe?