Definition
An archaic term from early English legal procedure meaning the making or waging of law — the formal act by which a party established or proved their legal right through a prescribed ritual process. The phrase appears in Magna Carta, chapter 21, in the context of earls and barons being amerced only by their peers and only per legem terrae (by the law of the land), with "open law" referring to the recognized, public modes of proof available under that law.
The term has no living doctrinal presence in modern Anglo-American law. It belongs entirely to the vocabulary of medieval English procedure and is encountered almost exclusively when reading primary sources from the period before the consolidation of the common law trial system.
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Common Confusion
Burrill's Law Dictionary defines open law specifically as trial by duel or ordeal — the older Germanic and Norman modes of proof in which divine judgment was invoked to resolve factual disputes. Black's, Bouvier's, and Rapalje & Lawrence describe it more broadly as "the making or waging of law," which encompassed compurgation (oath-helping) as well. These are related but distinct procedures. Researchers should not assume that any single source captures the full range of what "open law" or its Latin equivalent lex manifesta (manifest law) denoted across different periods and localities. The term functioned as a general reference to formal, public proof modes rather than a precise designation of one specific procedure.
Open law should not be confused with the modern colloquial phrase "open law" used in legal technology and access-to-justice contexts to describe free, publicly accessible legal resources or open-source legal databases. That usage is entirely modern, entirely informal, and has no connection to the historical legal term.
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Why It Matters in Research
Researchers will encounter "open law" almost exclusively when reading Magna Carta scholarship, medieval English legal history, or treatises on the writ system and early common law procedure. Its primary research significance is as a pointer: when you see the phrase, you are looking at a discussion of pre-modern proof mechanisms — compurgation, ordeal, or trial by combat — and you should trace the surrounding text accordingly.
The phrase per legem terrae in Magna Carta chapter 21 (and in the more frequently cited chapter 39, the due process ancestor) generated centuries of interpretive debate about what "law of the land" meant procedurally. Open law was one answer: the public, recognized modes of proof that gave the trial its legitimacy. Understanding this context is essential for researchers working on the historical foundations of due process, since later courts and commentators read "law of the land" forward into jury trial and eventually into modern procedural guarantees.
Burrill's cross-reference to lex manifesta is the most useful navigational tool in the historical dictionary shelf. Following that cross-reference will connect researchers to the broader Latin terminology — lex apparens, lex manifesta, wager of law — that appears in the primary sources and in Bracton, Glanvill, and Coke's Institutes, none of which use "open law" as a primary term.
The Rapalje & Lawrence entry adds a secondary pointer — a citation for "open lewdness" immediately following the open law definition — which reflects the alphabetical proximity of entries and is unrelated in substance. Researchers should not read a doctrinal connection between the two entries.
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Historical Dictionary Support
The four shelf sources agree on the core meaning: open law refers to the waging or making of law as described in Magna Carta, chapter 21. Black's, Bouvier's, and Rapalje & Lawrence are essentially identical, each offering a single-sentence definition with the Magna Carta citation.
Burrill's diverges usefully. By identifying open law specifically as trial by duel or ordeal and cross-referencing lex manifesta, Burrill's situates the term within the broader taxonomy of early proof modes rather than simply equating it with wager of law. This is the more historically precise framing. Wager of law (compurgation) was a distinct procedure from trial by battle, though both were species of what might broadly be called open or manifest law — proof conducted publicly before witnesses according to recognized ritual.
What the historical sources collectively miss is the procedural extinction of these modes: ordeal was condemned by the Fourth Lateran Council in 1215 (the same year as Magna Carta), trial by battle lingered nominally but fell into disuse, and wager of law survived longest before being abolished in England by statute in 1833. None of the shelf sources trace this trajectory, which matters for researchers trying to understand how the phrase evolved (or ceased to evolve) across legal history.
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Encyclopedia Cross-Reference
The Law Mind Property Law Encyclopedia: Future Interests — Remainder (Vested, Contingent, Subject to Open) [property_6] — The phrase "subject to open" in property law (describing a class gift that may expand as additional class members come into existence) is a distinct term of art with no connection to open law as defined here. The similar surface language is coincidental.
No Law Mind Encyclopedia entry directly addresses the historical wager of law or medieval English proof procedures.
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