For a man who has a son from a previous marriage (now divorced) and no children from the current marriage.
If the man dies what shares do his son and wife inherit?
If the wife dies what share does the husband inherit? Does the stepson inherit anything? Will this be different if there are other relatives? e.g., Parents are living or deceased?
In the name of Allah, the most Beneficent, the most Merciful.
The stepson does not inherit from the stepmother when she dies, as there is no cause for inheritance between the stepson and the stepmother. The causes of inheritance are lineage, slave-to-master and marriage.
If the husband passed away first and leaves behind a son and a wife, the inheritance will be distributed in the following way:
The property will be distributed into eight parts. One part will go to the wife and the remaining seven will go to the son, as he is a residuary (asabah).
If the wife was to pass away and she does not have any other relatives such as uncles, nephews etc. then the whole estate will go to the husband. The stepson will not inherit anything.
With regards to your final question the distribution of the estate will be different if any of the deceased has parents and other relatives alive at the time of death.
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham