This chapter will introduce the notion of causation based on counterfactual dependence. This notion forms the basis of the counterfactual account of causation. Different cases of overdetermination will be considered and it will be explained how these pose problems to the counterfactual account of causation. These problems motivate new ways of defining causation in terms of counterfactual conditionals, such as the account of causal influence or the causal modelling account. The point of view of causal contextualism will also be introduced—namely, the view that the truth of causal claims may vary relative to the context from which they are evaluated. Causal contextualism will be defended in many ways within this work. I will argue in this chapter that event fine-graining in the light of causal contextualism is at the basis of any strategy used to clarify overdetermination scenarios.