All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
Mandated will according to Article (279) of the Jordanian Personal Status Law means:
"If a person who has grandchildren whose father passed away before him or at the same time, then his (grandchildren) are entitled to one-third of his estate as a mandated will according to the following amount and conditions:
A- The mandated will to which these grandchildren are entitled equals their father`s share in the inheritance, supposing he was alive, provided that it doesn`t exceed one-third of the estate.
B- These grandchildren aren`t entitled to a mandated will if they are heirs of their father`s ascendants, grandfather or grandmother, or the grandfather wrote them a will or gifted them during his life time an amount equal to this mandated will. If he left them less than that mandated will, then that amount must be completed, but if it was more then the extra amount is a non-mandatory will. Also, if he left a will for some (grandchildren), then the others are entitled to the same share they are entitled to from the mandated will.
C- The mandated will belongs to the grandchildren and their descendants and so on, be they one or more; the male gets twice the share of the female. The descendant gets nothing if the ascendant is alive and each descendant gets only the share of his/her ascendant.
D- This mandated will must be executed first from the third of the estate."
The explanations of this Law may be reviewed for further understanding of this Article. And Allah the Almighty Knows Best.