In fables, the seventh son of the seventh son usually has great power and the ability to overcome all obstacles. He is born to be the hero and victorious in all struggles. Q WORKSHOP created a set of seven dice for the seventh edition of the excellent game Call of Cthulhu from Chaosium, one of the oldest publishers of role-playing games still in existence. Behold the Call of Cthulhu 7th Edition Blue & Green Dice Set. Believe me or not, sympathetic magic works. Seven is magic. So are our dice.