Roughly 99 percent of wills will go through the probate process without any problem. This is because the courts tend to stick to the language provided in them relatively strictly as they are seen as the voice of the deceased. However, there may be times when challenging a will may be worthwhile. For instance, if an individual did not have the mental capacity to create a will, it could be declared invalid.
Most individuals under 18 lack legal capacity to create a will. Adults with dementia or other mental illness may also be declared to lack capacity to make such a document. Fraud or undue influence on a testator may be grounds to declare a will to be invalid. If it can be proven that someone manipulated the testator into leaving assets or otherwise making changes to the will, that may constitute fraud or undue influence.
