 In many other states, including California and New York, the duty to defend is ascertained by also looking to "all" facts known to the insurer from any source; if those facts when read together with the complaint show that at least one claim is potentially covered (that is, the complaint actually alleges a claim of the kind which the insurer promised to defend or could be so amended in light of the known facts), the duty to defend is thereby triggered and the insurer must undertake the defense of its insured.This powerful bias in favor of finding coverage is one of the major innovations of U.S. law.Other common law jurisdictions outside of the U.S. continue to construe coverage much more narrowly.