A father remarries and has kids with his new wife. He has one child from his first marriage. When he falls ill, his second wife changes his will and leaves the kid from the first marriage out. What can the child do?
Children don't have the right to inherit, and a father has every right to leave his kid or kids out of his will, says the article, "Your parent left you out of their will: What now?" from New Jersey 101.5.
If the father is competent and not being unduly influenced by his current wife, he can decide to leave out the child from his first marriage. A husband frequently leaves everything to a spouse, even if it's a second marriage.
In some instances, a father may feel he's being fair by leaving a child out of his will. It could be that the child from his first marriage is significantly older than the children from his second marriage. Perhaps he paid for the education of that older child or even put a down payment on the first home of that child. In light of this, the father may believe he must leave the rest of his estate to his other younger children in order to put them in the same position as his first child. Or maybe the father feels comfortable that his oldest child is successful in life and that his half-siblings are more needy. Another scenario might be that the father provided for the child from his first marriage in some other manner, such as by naming him as a beneficiary of a life insurance policy, IRA, or other payable on death account that does not pass under the will.
Otherwise, if the father is competent, there is little a disinherited child can do. Upon the father's death, a child could contest the will, claiming undue influence by his new wife.
Reference: New Jersey 101.5 (November 19, 2015) "Your parent left you out of their will: What now?"