Rule of conjectural choice refers to a legal principle that no basis for recovery is presented when all theories of causation rest only on conjecture. Conjecture means a guess, supposition or surmise.
"As a theory of causation, a conjecture is simply an explanation consistent with known facts or conditions, but not deducible from them as a reasonable inference. There may be two or more plausible explanations as to how an event happened or what produced it; yet, if the evidence is without selective application to any one of them, they remain conjectures only. On the other hand, if there is evidence which point to any one theory of causation, indicating a logical sequence of cause and effect, then there is a juridical basis for such a determination, notwithstanding the existence of other plausible theories with or without support in the evidence."[Pontiac Sch. Dist. v. Miller, Canfield, Paddock & Stone, 221 Mich. App. 602, 614 (Mich. Ct. App. 1997)]