The Vienna Convention on the Law of Treaties sets the rules of treaty interpretation in articles 31-33. Yet these rules are quite vague, and they leave a lot of room for judicial discretion. The European Court of Human Rights (ECHR) has developed its own version of these rules of interpretation — a version that tracks the three traditional approaches to treaty interpretation: the textual approach, the subjective approach, and the teleological approach. Looking at the practice of the ECHR through the lens of these three traditional approaches highlights the logic of some of the court's interpretive choices, including its doctrine of deference: the Margin of Appreciation.