Definition
Opening a rule is the procedural act of restoring a court rule that has been made absolute back to its prior conditional state — typically to the status of a rule nisi — so that a party may be permitted to show cause against it. The effect is to undo the finality that attached when the rule was made absolute, reviving the opportunity for opposition that was foreclosed, usually through mistake or inadvertence.
The classic occasion for opening a rule arises when a rule to show cause is made absolute because the court was under the mistaken impression that no counsel had appeared or been instructed to oppose it. In such circumstances, the prevailing party — the one who obtained the absolute rule — will commonly consent to have the rule opened, allowing the opposing party a fair opportunity to be heard. The court then treats the rule as if it had never been made absolute.
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Common Confusion
OPENING A RULE vs. DISCHARGING A RULE vs. VACATING AN ORDER: These are distinct procedural outcomes and should not be conflated. Opening a rule restores it to conditional status; the underlying proceeding continues, and the opposing party may still show cause. Discharging a rule terminates it entirely — the party who sought the rule obtains nothing. Vacating an order is the broader modern equivalent of setting aside a judgment or order on substantive or procedural grounds, but it does not necessarily restore a prior conditional state. Researchers encountering these terms in historical sources must attend carefully to which outcome is described, as the consequences differ materially.
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Why It Matters in Research
This is a term of historical English common law procedure that largely disappeared from American practice as the rule nisi mechanism itself fell out of general use. Researchers will encounter it almost exclusively in pre-twentieth-century materials — English chancery and common law reports, early American state court records, and practice treatises from the eighteenth and nineteenth centuries.
The procedural context requires understanding: a rule nisi was a conditional court order requiring the opposing party to show cause why the rule should not be made absolute. If no cause was shown, the rule became absolute as a matter of course. Opening a rule was the safety valve — a consent-based or court-granted mechanism to correct the situation where absoluteness was reached by mistake rather than by genuine default or concession.
For corpus researchers, several traps exist. First, the term is embedded in a procedural vocabulary — rules nisi, rules absolute, rules to show cause — that modern practitioners do not use and that modern legal dictionaries treat incompletely. Without understanding the parent mechanism, the phrase opening a rule is opaque. Second, the act of opening was frequently accomplished by consent of the obtaining party, not by formal motion, meaning it may appear in records as a brief notation rather than a contested proceeding. Third, jurisdictional transplantation was uneven: some American states adopted this English procedural apparatus fully, others partially, and others replaced it with statutory motion practice. A researcher working across jurisdictions must not assume uniform application.
The term connects naturally to research on default judgments and the standards for relief from default — historically, opening a rule was the procedural ancestor of what modern civil procedure handles through motions to vacate or set aside under rules such as Federal Rule of Civil Procedure 60(b).
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Historical Dictionary Support
Black's, Rapalje & Lawrence, and Bouvier's are in close agreement — to the point of near-identical language — on the definition of opening a rule. All three describe it as the act of restoring or recalling a rule made absolute to its conditional state (as a rule nisi), so as to readmit the showing of cause. All three use the same illustrative scenario: the rule made absolute under a mistaken impression that no counsel was instructed to oppose it, with the obtaining party consenting to reopening.
The near-verbatim convergence across these three sources signals that all drew from a common English practice treatise lineage rather than from independent American development. Bouvier attributes the usage to Brown, likely a reference to an English practice manual. None of the three dictionaries provide meaningful analysis of when courts would open a rule over objection, or what standards governed a contested application to open — gaps that a researcher relying solely on dictionary definitions will need to fill from practice treatises and case reporters of the period.
What the historical sources miss: none address the decline of the mechanism or its relationship to modern motion practice. The silence on jurisdictional variation in American states is also notable.
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Jurisdictional Note
Opening a rule is a term of English common law procedure that was adopted to varying degrees in American state courts. States with strong English procedural heritage (particularly in the East) employed it most consistently; others absorbed the underlying concept into statutory motion practice without retaining the terminology. The term should not be imported into modern jurisdictional research without confirming that the relevant court system actually employed the rule nisi procedure.
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