South Dakota Codified Laws
Chapter 01 - The Nature Of Obligations
Section 20-1-3 - Kinds of obligations arising by operation of law.

20-1-3. Kinds of obligations arising by operation of law.
An obligation arising by operation of law may be either a general legal duty imposed upon all persons indifferently by law or a legal duty affixed by operation of law to a status or relationship voluntarily assumed.

Source: SDC 1939, ยง47.0103.