Attorney‑client privilege and the work product doctrine are two of the most important legal protections available to businesses operating in the United States. Both serve to protect sensitive legal information from disclosure, particularly in litigation, regulatory inquiries, and government investigations. Despite their frequent invocation—often together—the two doctrines are distinct in purpose, scope, strength, and vulnerability. Confusing them, or assuming they operate identically, can result in the loss of protection, unnecessary disclosures, and strategic disadvantage.