A last will and testament may be contested on numerous grounds, the most common of which include challenges for lack of capacity, fraud, duress, and/or undue influence.
There are strict, specific deadlines for challenging a will. While the deadline varies, a will contest is usually pursued after a will is admitted to probate. An order admitting to or rejecting wills from probate may not be appealed. The will contest is in effect an appeal from the original order admitting or rejecting the will. Kinder v. Brune, 754 S.W.2d 946, 948 (Mo. Ct. App. 1988). The only procedure for challenging the admission of a will to probate is by way of a will contest. Gilmore v. Erb, 900 S.W.2d 669, 670 (Mo. Ct. App. 1995).
In addition to meticulous deadlines, a will contest also has particular rules with respect to who needs to be made a party to the action. Other than the typical plaintiffs and defendants, “interested parties” need to be joined in the suit — and specifically any person who will be “adversely affected” by the will contest suit. Section 473.083.3, RSMo.
To ascertain whether an interested person will be “affected adversely,” the analysis centers on whether an interested person “may lose some protected benefit if the contestant wins.” Zimmerman v. Preuss, 725 S.W.2d 876, 877 (Mo. 1987).