Meaning
Evidentiary principles in multi-party litigation measure whether shared legal interests permit the disclosure of privileged communications without waiving protection. Invoking the common interest doctrine allows separate corporate entities and their counsel to share confidential attorney-client communications. The doctrine applies when parties share a common legal interest in pending or anticipated legal proceedings.
Application stops when parties become adverse in litigation or when disclosures cover purely commercial strategy rather than joint legal defense.
Joint Defense Alignment
Co-defendants align legal strategies by executing written agreements before sharing work product. Establishing a common interest doctrine arrangement requires identical legal objectives across all participating parties. Shared economic goals without legal alignment fail to support the doctrine.
Privilege Maintenance
Protection remains intact against third parties despite documents crossing corporate boundaries. Legal memos and factual summaries shared under the doctrine retain full attorney-client privilege. Confidentiality survives as long as the joint defense agreement remains in effect.
Scope Limit
Subsequent litigation between former participants completely waives privilege for all communications previously shared under the joint agreement. Disclosures made to commercial partners during ordinary merger negotiations fall outside the doctrine when no active legal threat exists. The rule protects shared legal defense work product exclusively.
