What happens if a person wishes to leave nothing to one of their heirs, e.g., one of their three sons? Many states' laws assume, in the absence of naming the son in the will, that the son was forgotten. This means that in many states, despite the intention of the person making the will to leave nothing to the son, the fact that the son was left out of the will produces the exact opposite result - the son inherits his one-third of the estate.
To be safe, many lawyers advocate putting a provision in the will which names the son you wish to disinherit, and then leaves $1 to that person. While the author has heard many people state that "they couldn't bear to leave even a dollar to that person," having that person receive one dollar is much better than one-third of the estate, if it is not intended.
Disinheritance is another tricky subject, and it should not be done without the advice of an attorney. Contact member services to speak to an attorney to make sure your wishes are followed.