When a contract provides an exclusive method by which its consideration is to be ascertained, and such method appears possible on its face, but in fact is or becomes impossible of execution, such provision only is void.
N.D. Cent. Code § 9-05-09
Method of determining consideration becomes impossible - Provision void
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.