Does the stepfather's adopted son outside have the right to inherit?

Yes The children stipulated in the Marriage Law include not only children born in wedlock, but also children born out of wedlock, adopted children and stepchildren who have the obligation to support according to law. According to the provisions of the inheritance law, the heirs in the first order are the spouse, children and parents of the decedent. Therefore, adopted children enjoy the same inheritance rights as their own children.