>But as a matter of contract law - inheritance, medical proxy etc - it makes sense for the state to be involved to that degree. (and it really should let the contract be just as flexible for the number of partners etc but of course that is like making chess a three-dimensional game ;-)

Off topic: Someone once gave me a 3D chess 'board' . AFAICS completely unplayable. Also came across a version for 4 players (board extended by two ranks on each side) - ditto.