The law allows for wills to be challenged, but only if you can prove that the person was not competent to sign a will, that there was something wrong in how the will was signed, that the person was threatened to sign the will, that someone put an unfair amount of pressure on them to sign the will or include certain things in the will, or that the will was fraudulent in some way.  The process of challenging a will can be very costly and will take a long time.  You may also be required to pay the estate’s costs if it turns out the will was valid and that your challenge to it had no merit.