Yale law professor Ian Ayres continues his American Contract Law course with a session on warranties and representations of fact, part of the unit on contract performance. He works through how courts distinguish a warranty, a promise about the truth of a fact tied to a bargain, from a mere representation or opinion, and why that distinction determines whether a buyer can sue for breach when a statement turns out false. Expect discussion of seller statements in sales transactions, the line between puffery and an actionable factual claim, and how remedies differ depending on which category a statement falls into. The lecture runs about sixteen minutes and is drawn from Ayres' Coursera courses, delivered in a straightforward classroom lecture style aimed at students working through the mechanics of contract doctrine step by step.