A lawsuit seeking a declaratory judgment—also known as a “deck action” (dec. action)—is a lawsuit that asks the court to determine the rights, status, or other legal relations of the parties when a controversy has arisen, but before a wrong has been committed. A declaratory judgment seeks to prevent further litigation, liability, and harm. Declaratory relief is not available to settle disputes already pending before a court. A declaratory judgment is improper if the relief requested is raised for the first time in an amended petition (lawsuit) and merely addresses the same issues as were raised in the original petition.

A declaratory judgment is often sought when there is a disagreement over the meaning or application of an insurance policy or other contract, or a deed, will, trust, lease, statute, or municipal ordinance.

In Missouri, a declaratory judgment, or 'dec action,' is a legal remedy used to resolve uncertainties and disputes over legal rights, status, or relationships before any actual damage or infringement has occurred. This type of action is particularly useful in cases where parties are in disagreement over the interpretation or application of legal documents such as contracts, insurance policies, wills, trusts, leases, statutes, or ordinances. The purpose of a declaratory judgment is to provide clarity and prevent future litigation or harm. Under Missouri law, declaratory relief is not intended to address issues that are already the subject of ongoing litigation. Additionally, it is not proper to seek a declaratory judgment for an issue that is introduced for the first time in an amended petition if it simply reiterates issues already raised in the original petition. The relevant Missouri statutes governing declaratory judgments can be found in Chapter 527 of the Missouri Revised Statutes.