I remember, long ago, when I was a kid, I read a story in a book on Egyptian mythology about two animals, a cat and a vulture, made an oath in the name of Ra that neither would harm each other’s child. The vulture later snatched up the cat’s cub, and the cat called on Ra for retribution. In hearing that the promise was in his name, Ra was obliged and struck down the vulture’s chicks with sun stroke.
I’ve been very interested in doing something similar. The idea that, if I can get a promise out of someone, I can trap them in an enchantment where breaking it would constitute divine retribution, fitting to the crime. Course, I’m not talking about anything as severe as the story above. Though, I’d be under the same enchantment, but I’d be the one designing the terms in the beginning.
Forms of this did not seem to be too uncommon for the medieval Norse. There are stories of people making oaths and suffering for breaking them.
I would say, you should both invoke a certain powerful deity associated with oaths or law, and make an oath to them to hold up your end of the agreement, and do this in full faith and will.
I will say, making oaths to deities is a sure way to become terribly cursed very quickly.
In my previous answer, you would be designing the terms (or at least, both of you would agree on the terms. It would not be quite as possible to do this as powerfully if the other party’s soul was not united in this). There are still ways you could do it, as I’ve read some example rituals from some Wicca books long ago, but not as powerfully.
If you be doing it you better pick the correct deity cuz some might not take kind to having their name invoked in a promise the intent of which is to trick the other person into breaking it so they (the deity in question) can punish them for breaking it.
Some deities might think it isn’t on the square and might just do something to you for the promise you tricked the person into IF you did something to cause them to break that promise.
So if you be doing this, be sure you pick a deity or spirit that isn’t gonna take you to task if you as well as the other person if your intending to cause them to break the promise in its name.
Add: I said the above because how you worded it made me think you want to get them to swear in deity x’s name then go find a way to trick them into breaking it afterwards. I know if I was a full on deity I’d do something on the person who caused the promise to be naked and then went round manufacturing a situation where the person who made it at their instigation then broke it (cuz I’d consider tricking h to e person into breaking it after encouraging them to make it to be a person playing dirty. But that’s just me cuz it would violate my sense of fair play).
Add: So I advise design the promise situation fairly or make sure to choose a deity who does not have a strong sense of honour and fair play (if you plant to design the breakage of said promise as well as causing its being made in the first place).
Basically, my mindset is survival. There are people around who have a greater ability to trick, deceive, and manipulate. Whether that be me, another person or people (particularly in a position of power), or the law. And I’m very trusting. So, for me, that isn’t “Square”.
The intent isn’t to bully or deceive, but to make sure that I am not bullied or deceived. To me, morality exists so people can trust each other, and work/live together. Unfortunately, I’ve been burnt before.
Particularly by authority figures, or people who can use morality against me. So, pardon me if I don’t trust people. But that’s the point.
As said, I don’t think it’s “Square” if someone has some sort of advantage that they can lord over me. I do think it’s “Square” if I had some sort of means to feel more insured that I can trust someone. If however I am deceived, or the other person uses their position to bully me, I at least know that they won’t get away with it.
After all, my greatest fear is to put my trust in someone, be betrayed, and have to pay for it throughout the rest of my life. One deception can have nigh irreversible damage, especially if its someone with authority. Once again, it’s happened once or twice before. And in those instances, I’ve learned that some people have the power to break promises. So, it takes power to hold them.
But you’re right that I can’t bother a deity with this sort of thing if I don’t necessarily have their favor.