There shall be one form of action to be known as “civil action”.
Rule 42.01.One Form of Action.
Part I · Rule 42: Form of Civil Action · Not amended since adoption on record · Last verified July 22, 2026
In one sentenceThis rule abolishes any distinction between different forms of civil lawsuits in Missouri, replacing older categories with a single, unified form of action known as the “civil action.”
Full Text of Rule 42.01
Official Comment
This is the same as Section 4 of the 1943 Code (Sec. 506.040, RSMo 1959) and Rule 2 of the Federal Rules of Civil Procedure.
Plain-English Summary
Rule 42.01 is one sentence long, and it does one thing: it declares that there is one form of action, called a “civil action.” Older systems of procedure sorted lawsuits into separate categories, each with its own technical rules and required forms. Missouri, like the federal courts, did away with that separation. Whatever the underlying dispute — contract, property, tort, or otherwise — a Missouri civil case proceeds as a single, unified “civil action” under the same set of procedural rules.
For a litigant, the practical effect is that there is no need to select among competing procedural tracks based on the legal theory of the case. The rules governing pleadings, service, discovery, and trial in Rules 41 through 101 apply the same way regardless of the substantive claim being asserted.
Frequently Asked Questions
What does “one form of action” mean in practice?
It means a Missouri lawsuit is filed and proceeds as a single type of case, called a “civil action,” instead of being sorted into separate procedural categories based on the type of claim.
Do different claims, like contract versus property disputes, follow different procedural rules under this rule?
No. All such claims proceed under the same civil action framework and the same set of civil procedure rules.
Is this similar to federal practice?
Yes, the federal rules adopted the same single form of action, and Missouri’s rule serves the same purpose for state court practice.
Does this rule affect which specific rules apply to my case, such as probate carve-outs?
No. Rule 42.01 addresses the form of the action itself; questions about which specific rules apply to a probate or associate circuit case are addressed by Rule 41.01.
Did Missouri always have a single form of civil action?
The rule traces back to the 1943 Code and has continued as the standard since these rules were adopted.
Source & verification. Rule text and amendment history are
reproduced verbatim from the Missouri State & Federal Court Rules, adopted by the
Supreme Court of Missouri. Last verified July 22, 2026. ·
Official source
Also known as: one form of civil action missouritypes of lawsuits missouricivil action definition rulesingle procedural trackno separate forms of action