S.D. Codified Laws § 54-8A-10
Current with legislation signed by the governor on or before 3/6/2024
Unless displaced by the provisions of this chapter, the principles of law and equity, including the law merchant and the law relating to principal and agent, estoppel, laches, fraud, misrepresentation, duress, coercion, mistake, insolvency, or other validating or invalidating cause, supplement its provisions.
SDCL 54-8A-10