Sam: That’s an interesting question.
Secular law generally views the moral obligation of a contract to either perform, or to pay the appropriate damages. That is, it is understood from the beginning that it would not be worth it for the parties to make a contract if they were bound to it no matter what.
It is a bit funny that halacha would have a sense of contract which doesn’t really make sense. And I wonder what it is.
I’m not totally clear where contracts are enforceable in halacha anyway, since some of them should be asmachta.