The ideal of clear and simple jurisdictional rules seems like a no-brainer. Clarity in areas of subject-matter jurisdiction generally reduces the cost of litigating those issues and thus preserves litigant and judicial resources for the merits of a dispute. As a result, scholars and justices regularly promote the rhetoric of jurisdictional clarity. Yet no one has probed that rhetoric or reconciled it with the reality of subject-matter jurisdiction doctrine, which is anything but clear and simple. This Article begins to fill that gap, and, in the process, shifts the perspective of existing conversations between rules and standards and between mandates and discretion toward a perspective that focuses on the value and attainability of clarity. It offers a more refined understanding of the surprising uncertainty and complexity of jurisdictional clarity, and it argues that, contrary to the rhetoric, the ideal of jurisdictional clarity is mostly illusory. Difficulties inherent in the design, implementation, and instrumental direction of clear and simple jurisdictional rules largely render them unattainable. Rather than continue to invoke the unexamined ideal of clarity and simplicity, jurisdictional doctrine should strive to confine clarity to what it can reasonably accomplish and to embrace the undervalued virtues of uncertainty and complexity.