Experience suggests that strategy entails some interplay of choice, chance, and determinism as causal elements. Specifically, strategy is predicated on causality, or the principle that strategic choices have causes as well as consequences. Yet our discipline lacks a fundamental theory of causation, one that integrates strategic choice and deterministic perspectives and leaves room for chance. In reply, we venture beyond strategy and the organization sciences into intellectual history and complexity theory. Not only does each tradition have a long and respected track record in confronting causation, but when combined they allow us to address epistemological and ontological issues alike. We conclude with three propositions on the nature of causation in strategy, and examine their epistemological and methodological consequences.