Chapter 7 analyzes the applicability criterion of arguability, which requires that the applicant has an arguable claim that substantive rights in the Convention are violated for Article 13 to apply. The chapter first queries how this criterion relates to the scope of application of substantive rights. Is it sufficient to be arguably within the scope of substantive rights, for Article 13 to apply, or is it necessary to actually be within the scope? Although the Court's case law is not explicit, it reveals that it is necessary to be within the scope. This result is critcized. The chapter proceeds by analyzing the required threshold of arguability. Even though the Court has not provided an abstract definition, but, rather, determines on a case-by-case basis whether each individual claim is arguable, the Court has linked arguability to the international admissibility criterion of manifestly ill-founded. However, this adversely affects the arguability ctest and does not chime well with the principle of subsidiarity. The chapter argues that the Court needs to remove this linkage.