What requires a defendant's own intentional conduct for fulfilling jurisdiction criteria?

Purposeful availment is the concept that requires a defendant's own intentional conduct to establish personal jurisdiction. This principle is grounded in the idea that a defendant should be able to anticipate being brought into court in a particular state based on their deliberate actions in that state. For instance, if a business actively markets its products in a specific state, engages with local customers, or has a physical presence there, it can be said to have purposefully availed itself of the privilege of conducting activities within that state's jurisdiction. This purposeful conduct creates a connection between the defendant and the forum state, making it reasonable for the court in that state to assert jurisdiction over the defendant.

In contrast, adequate notice refers to the legal requirement that defendants must be informed about the legal proceedings against them, but it does not inherently involve the defendant's intentional actions. Consent relates to when a defendant agrees to submit to the jurisdiction of a court, which may or may not involve intentional conduct in terms of their relationship to the jurisdiction itself. Fair play reflects a general standard of justice but does not specifically focus on the defendant's own actions that would invoke jurisdiction. Purposeful availment, therefore, directly connects the defendant's intentional conduct to the requirement for establishing jurisdiction.