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 Massachusetts, a declaratory judgment, or 'dec action,' is a legal remedy available through the courts that allows parties to seek a judicial determination of their legal rights, status, or other relationships under a contract, statute, or other legal document before any breach or harm has occurred. This type of action is used to clarify legal obligations and can prevent further litigation or disputes. It is commonly used in cases involving insurance policies, contracts, deeds, wills, trusts, leases, statutes, or municipal ordinances. However, Massachusetts law stipulates that declaratory relief is not appropriate for disputes that are already being litigated in court. Additionally, a declaratory judgment cannot be sought through an amended petition if it simply rehashes issues that were already raised in the original petition. The purpose of a declaratory judgment is to resolve uncertainty and provide clarity on legal matters, not to revisit or alter decisions on issues that have already been addressed by the court.