Passing your estate to your heirs is not a guaranteed thing in many cases. There is always a degree of uncertainty because people and unforeseen events can occur that could thwart your intentions—even when written in your estate-planning documents. It is especially true if your documents do not allow for any flexibility in the wording.
Flexibility in your estate plan enables your documents to work around many unforeseen situations. The documents need to be carefully worded so that your intentions are clear, as well as any contingencies you may want to put in place to protect your assets from being put into the hands of irresponsible people.
