S.D. Codified Laws § 53-9-8 : — CONTRACTSUNLAWFUL CONTRACTS —9-8 - Contracts in restraint of trade void-Exceptions TEXT PDF Any contract restraining exercise of a lawful profession, trade, or business is void to that extent, except as provided by §§ 53-9-9 to 53-9-12, inclusive. SDCL 53-9-8 CivC 1877, § 959; CL 1887, § 3583; RCivC 1903, § 1277; RC 1919, § 898; SDC 1939, § 10.0706; SL 2005, ch 254, §1.