While any individual with "legal standing" can challenge a will, successful contests are statistically rare. Challenges are typically brought by close relatives who believe they were unfairly excluded or that the document does not reflect the true wishes of the deceased.

Common Grounds for Invalidation

To successfully overturn a will, a challenger must prove one of the following "fatal flaws" in court:

• Lack of Capacity: Evidence that the deceased was not of "sound mind" due to dementia, illness, or other impairment at the time of signing.
• Undue Influence: Proof that the deceased was coerced or improperly pressured by a person in a position of trust to change their beneficiaries.
• Improper Execution: The will failed to meet state requirements for signatures, dating, or disinterested witnesses.
• Fraud or Forgery: The document or the signature is proven to be counterfeit, or the deceased was misled about what they were signing.

Rights of Spouses and Children

Generally, only spouses have a legal right to a portion of an estate. Most states have "Elective Share" laws that prevent a spouse from being entirely disinherited. In contrast, children can generally be disinherited, provided the exclusion is stated clearly. If a child is omitted without explanation, a court may rule the omission was unintentional and grant them a share under "Pretermited Heir" statutes.

Preventative Measures

To discourage legal battles, many include a "No-Contest Clause," which stipulates that any beneficiary who unsuccessfully challenges the will loses their entire inheritance. Additionally, keeping a will up-to-date and using a Self-Proving Affidavit (notarized signatures) can significantly strengthen the document against future claims.