In cases of uncertainty not removed by the preceding rules, the language of a contract should be interpreted most strongly against the party who caused the uncertainty to exist. The promisor is presumed to be such party, except in a contract between a public officer or body, as such, and a private party, and in such case it is presumed that all uncertainty was caused by the private party.
N.D. Cent. Code § 9-07-19
Uncertainty interpreted against party causing it - Presumption as to cause
Official source: North Dakota Legislative Branch. Reproduced from public-domain North Dakota statutes; confirm against the official source for the current text. Not legal advice.