From a technical perspective, adult children should not expect to inherit anything, as they have no right to do so. That is to say, you do not have to leave assets to every one of your heirs — and they are not being wronged, legally speaking, if you choose not to do so.
This may lead you to believe that all you have to do is leave someone out of the will to keep them from getting your assets. Say you want to leave everything to your eldest and nothing to your second child. As long as the will states that your assets go to your eldest and says nothing about your second child — as if he or she did not exist — you may think that’s enough.
The risk of a will contest
The problem with this approach is that your will may be contested by that unhappy heir. They could state that you must have overlooked them or made an accidental error in leaving them out of the will. There are cases where this type of contest overrules the will and transfers assets to that heir.
To counter this, you may want to add a disinheritance clause. It really does not have to do much besides naming your heir and declaring your intention to leave them no part of your estate. This eliminates the ability to challenge on the grounds of “accidental” disinheritance, though there are still other potential challenges, such as undue influence (or the idea that you were manipulated into favoring one heir over another).
You don’t want to make any mistakes with your estate plan, so be very sure you know exactly what steps to take and how to set everything up so that your worldly goods go where you want them to go.