In The Insurer’s Duty to Defend: A Quick Analysis, attorney and insurance expert witness Thomas H. Veitch describes some general rules applied by Texas courts and other jurisdictions following the “Eight Corners Analysis” regarding a duty to defend.
The insurer’s duty to defend is a contractual duty determined by the provisions of the insurance policy.
The eight-corners rule emanates from the fact that only two documents are considered relevant to the determination of the duty to defend, i.e., the policy and the pleadings.