The most valuable thing a liability policy provides is usually not the money at the end but the lawyer at the beginning. This article explains the duty to defend: where it comes from, why it is broader than the duty to indemnify, and how a single ambiguous allegation in a complaint can obligate an insurer to fund years of litigation. It walks through what happens after a claim is tendered, what a reservation of rights actually reserves, when a policyholder gets to choose its own counsel at the insurer's expense, and how coverage disputes are resolved while the underlying case proceeds. It covers the consequences of getting it wrong in both directions, including the excess judgment exposure that makes a wrongful refusal to defend one of the most expensive mistakes an insurer can make. Readers finish understanding what to tender, when, to whom, and what to do when the answer is a denial or a reservation.