Where a contract provides an exclusive method by which its consideration is to be ascertained, which method appears possible on its face but in fact is or becomes impossible of execution, such provision only is void.
S.D. Codified Laws § 53-6-10
Effect of impossibility of ascertaining consideration--Possible of execution on face
Source: CivC 1877, § 914; CL 1887, § 3538; RCivC 1903, § 1232; RC 1919, § 847; SDC 1939, § 10.0505.
Official source: South Dakota Legislature. Reproduced from public-domain South Dakota statutes; confirm against the official source for the current text. Not legal advice.