I don't think this is true; these are just policies set by his executors and the Foundation, not even in the will of Nobel [1]. Even the posthumous restriction is more an implicit reading of his phrasing, that the prize (money) should be awarded to such a person (rather than the person or in honor of the person).

And in fact the three person limit seems to already stretch his definition.

It seems that this would be easily changeable by the foundation, as there is nobody with standing or grounds to contest the changes, as Nobel and his executors have long since left us to our own devices.

[1] https://en.wikipedia.org/wiki/Nobel_Foundation, and https://www.nobelprize.org/alfred-nobel/full-text-of-alfred-... for complete text.

Curious: What would happen if they did make changes? Who would enforce it?

If I understand paragraph 1 of the statutes of the Nobel Foundation [1] correctly, a settlement between the Foundation and the heirs of Nobel forbid it from deviating from some "main principles", which include that the award shall not be divided into more than three parts. So presumably, if they amended this rule, they could be sued by the heirs. Also, paragraph 23 suggests that any amendments to the statutes must respect paragraph 1.

[1] https://www.nobelprize.org/about/statutes-of-the-nobel-found...

I think the fund for it was set up from the trust of Alfred Nobel in accordance with his will. So presumably whatever law in Norway involves trusts and enforcing peoples last will would be binding on the fund, and thus on the committee

*Sweden