In the face of all the new rules I sincerely hope I don't end up violating any of them.

This is like my land-law thread, I use the concepts I'm discussing in my worlds, but they're not specific in my worlds alone and I'm interested in other people's view on the concept. But unlike land-law I think bindings are more magical related than not. Hence putting them here.
I first started thinking about this when I was listening to a song based on an old Welsh legend. The verse in question goes:
"Fair Olwen was the daughter of the giant Ysbaddaden
Who would never let her marry, for when she wed he'd die."
And my sister asked me, "What does it mean, when she wed he'd die? Why would he die? That doesn't make any sense." And my answer was that I guess he was bound. Which led to a big discussion on what on earth I meant by that.
If Ysbaddaden was bound, then it simply means when his daughter wed, he'd die. One way or another. He was fated so to speak. The other alternatives are that he was cursed, or that he was sworn. "I'll die before I let you marry!!!" But if it was a curse I think it would be mentioned in the song, and it's not. And binding makes the most sense. You don't try to understand it, it's just... fated. It is.
In the unfinished Lord of the Dance series (which I have if anyone wants to read them,) they practice a form of binding between the kings and the dancers. They go through a whole ceremony and the enforce a code between them. The code, the king, and the dancers are all bound. And if the binding is broken the code will punish the malefactor. The binding can also be broken by the dancers at any time they choose. So this is a more realistic form of bindings, something tangible, with rules and substance.
Oaths are often very binding. In some books I've read an oath is a binding that you swear to yourself. Binding is a very useful principle in marriages. It was used in both Lord of the Dance and I used it in Trice. When people are bound to each other They share... oh I don't know. Use your imagination. A soul? A mind? They can feel each other's pain, and almost read each others minds, although it's nothing as coherent and actually mindspeaking. It's just... a binding. In the legend of Deirdre when her husband dies, she dies too, for no other reason than that he was dead. I imagine a binding could work like that too, your lives are tied together. The death of one is the death of the other. Not a curse, curses are similar, but not the same.
EXAMPLE: Balan was cursed. When he chose to keep the damsel's sword he knew it came with a curse, that he would kill his dearest friend with it. So when Balan and his brother Balin fight and kill each other, not knowing who the other is that is the result of a curse.
Belu and Bilo were bound. They hated each other, but they never fought, because when one died, the other would die also. Not a curse, a binding. They were stuck with each other, through no one's doing... fated so to speak.
Binding and fate are also different, even though I use fate to describe a binding. Fate is something shaped by events. Fate is something that, depending on your world structure, can be thwarted. Binding is more like land law.
Thoughts?