For faster navigation, this Iframe is preloading the Wikiwand page for Ambiguity (law).

Ambiguity (law)

Ambiguity occurs when a single word or phrase may be interpreted in two or more ways. As law frequently involves lengthy, complex texts, ambiguity is common. Thus, courts have evolved various doctrines for dealing with cases in which legal texts are ambiguous.

Criminal law

In criminal law, the rule of lenity holds that where a criminal statute is ambiguous, the meaning most favorable to the defendant—i.e., the one that imposes the lowest penalties—should be adopted.[1] In the US context, Justice John Marshall stated the rule thus in United States v. Wiltberger:

The rule that penal laws are to be construed strictly, is perhaps not much less old than construction itself. It is founded on the tenderness of the law for the rights of individuals; and on the plain principle that the power of punishment is vested in the legislative, not in the judicial department. It is the legislature, not the Court, which is to define a crime, and ordain its punishment.[2]

Contract law

In contract law, the contra proferentem rule holds that, depending on the circumstances, ambiguous terms in a contract may be construed in favor of the party with less bargaining power.[3]

International law

In Canada, courts have developed rules of construction to interpret ambiguities in treaties between Indigenous peoples and the Crown.[4] In 1983, the Supreme Court of Canada held that "treaties and statutes relating to Indians should be liberally construed and doubtful expressions resolved in favour of the Indians."[5]

Property law

In property law, a distinction is drawn between patent ambiguity and latent ambiguity. The two forms of ambiguity differ in two respects: (1) what led to the existence of the ambiguity; and (2) the type of evidentiary basis that might be allowed in resolving it.

Patent ambiguity

Patent ambiguity is that ambiguity which is apparent on the face of an instrument to any one perusing it, even if unacquainted with the circumstances of the parties.[6] In the case of a patent ambiguity, parol evidence is admissible to explain only what has been written, not what the writer intended to write. For example, in Saunderson v Piper (1839),[7] where a bill of exchange was drawn in figures for £245 and in words for two hundred pounds, evidence that "and forty-five" had been omitted by mistake was rejected. But where it appears from the general context of the instrument what the parties really meant, the instrument will be construed as if there was no ambiguity, as in Saye and Sele's case (1795),[8] where the name of the grantor had been omitted in the operative part of a grant, but, as it was clear from another part of the grant who he was, the deed was held to be valid.[9]

Latent ambiguity

Latent ambiguity is where the wording of an instrument is on the face of it clear and intelligible, but may, at the same time, apply equally to two different things or subject matters, as where a legacy is given "to my nephew, John," and the testator is shown to have two nephews of that name. A latent ambiguity may be explained by parol evidence: the ambiguity has been brought about by circumstances extraneous to the instrument, so the explanation must necessarily be sought in such circumstances.[9]


  1. ^ "The New Rule of Lenity". Harvard Law Review. 119 (8): 2420–2441. June 2006. JSTOR 4093511.
  2. ^ United States v. Wiltberger, 18 U.S. (5 Wheat.) 76 (1820) at paragraph 5 (Supreme Court of the United States).
  3. ^ Horton, David (2009). "Flipping the Script: Contra Proferentem and Standard Form Contracts". University of Colorado Law Review. 80 (2): 431–486 – via HeinOnline.
  4. ^ Rotman, Leonard I. (1997). "Taking Aim at the Canons of Treaty Interpretation in Canadian Aboriginal Rights Jurisprudence". University of New Brunswick Law Journal. 46: 11–52 – via HeinOnline.
  5. ^ Nowegijick v The Queen, [1983] 1 SCR 29, 1983 CanLII 18 at 33 (Supreme Court of Canada). See also R v Badger, [1996] 1 SCR 771, 1996 CanLII 236 (Supreme Court of Canada) and Elliott, David W. (1996). "Aboriginal Peoples in Canada and the United States and the Scope of the Special Fiduciary Relationship". Manitoba Law Journal. 24 (1): 137–186. 1996 CanLIIDocs 162 – via CanLII. at note 49 and accompanying text.
  6. ^ Lehman, Jeffrey; Phelps, Shirelle (2005). West's Encyclopedia of American Law, Vol. 1 (2 ed.). Detroit: Thomson/Gale. p. 243. ISBN 9780787663742.
  7. ^ 5 Bing (N.C.) 425.
  8. ^ 10 Mod. 40, 88 E.R. 617.
  9. ^ a b  One or more of the preceding sentences incorporates text from a publication now in the public domainChisholm, Hugh, ed. (1911). "Ambiguity". Encyclopædia Britannica. Vol. 1 (11th ed.). Cambridge University Press. pp. 794–795.
{{bottomLinkPreText}} {{bottomLinkText}}
Ambiguity (law)
Listen to this article

This browser is not supported by Wikiwand :(
Wikiwand requires a browser with modern capabilities in order to provide you with the best reading experience.
Please download and use one of the following browsers:

This article was just edited, click to reload
This article has been deleted on Wikipedia (Why?)

Back to homepage

Please click Add in the dialog above
Please click Allow in the top-left corner,
then click Install Now in the dialog
Please click Open in the download dialog,
then click Install
Please click the "Downloads" icon in the Safari toolbar, open the first download in the list,
then click Install

Install Wikiwand

Install on Chrome Install on Firefox
Don't forget to rate us

Tell your friends about Wikiwand!

Gmail Facebook Twitter Link

Enjoying Wikiwand?

Tell your friends and spread the love:
Share on Gmail Share on Facebook Share on Twitter Share on Buffer

Our magic isn't perfect

You can help our automatic cover photo selection by reporting an unsuitable photo.

This photo is visually disturbing This photo is not a good choice

Thank you for helping!

Your input will affect cover photo selection, along with input from other users.


Get ready for Wikiwand 2.0 🎉! the new version arrives on September 1st! Don't want to wait?