Intention to create legal relations
But I never thought it would come to this....
There is some debate on whether the intention to create legal relations is a separate ingredient in a legally binding contract, or really just an evaluative description of what all the other ingredients (offer, acceptance and consideration) add up to.
Their worshipful honours have held<ref>Edwards v Skyways [1964] 1WLR 349 that in an “express” contract or an “ordinary commercial transaction”, the burden of proof is on she who alleges the absence of an intention (but really? if, in actually signing a legal agreement, you did not intend to create legal relations, then what on earth did you think you were doing?) Where contract implied from conduct, then the person claiming the contract has the burden of proof. But this seems to be no more than a burden of proving offer and acceptance in the first place.
There is some judicial authority that the intention to create legal relations is a separate thing, but dammit, that legal authority, however binding it might be, is wrong.
As the maxim has it, anus matronae parvae malas leges faciunt.
This is a contrarian view, by the way. The clue is in the url.