Article III standing requires injury in fact, causation, and redressability for federal jurisdiction.

Choice of law determines which jurisdiction's substantive law governs a dispute connected to multiple states.

The Erie doctrine requires federal courts sitting in diversity to apply state substantive law and federal procedural law.

Full faith and credit requires states to recognize the judicial proceedings and judgments of other states.

Justiciability is the collection of doctrines determining whether a dispute is appropriate for judicial resolution.

Mootness bars adjudication where the controversy has ended and no effective relief remains available.

Ripeness requires that a dispute be sufficiently developed for judicial resolution rather than hypothetical.

Standing is the requirement that a plaintiff have a concrete injury traceable to the defendant and redressable by a favorable decision.