Causation is typically conceptualised as a two-step process, comprising a factual and a normative component. In accordance with this respective two-tiered understanding of causation and with a strong reliance on the findings of the preceding chapter’s analysis, this chapter focuses on the initial step of causal determination within the legal context, namely factual causation. It introduces different approaches to factual causation, both metaphysically grown concepts such as counterfactual causation, theories of regularity and probability as well as doctrines that have just recently been emerging and are mainly developed in a broader case law dynamic. Among these are, in particular, a emission-share and a contribution-based doctrine. In this context, reference is commonly drawn to transdisciplinary approaches, originating from natural science and mathematics. The overarching focus of this chapter persists in reconciling perceptions of causation with actual causation and scientific findings. The ultimate aim is to show how the application and adaptation of specific causal doctrines can resolve the dilemma of the divergence between actual causation and causation in law.