Create a new rule called “Mystery Variable”:

EMs have a Mystery Variable, which is an integer tracked in the GNDT. Once per dynasty, an EM can set their Mystery Variable to a number that isn’t 0. An EM cannot take dynastic actions unless their Mystery Variable has been set in this way. A Mystery Variable defaults to 0.

If the current month is November and this paragraph hasn’t been removed, new proposals must propose to remove this paragraph (ie. this one starting with “If the current month (...)” and ending with “(...) meaning to the game”). This paragraph should be removed along having the Mystery Variable renamed along having it given a further meaning to the game.