This Understanding treatise is designed for first-year law students enrolled in Contracts. The text explains common law principles of contract law using cases and examples that students commonly encounter in this first-year course. It draws illustrations from the Restatement (Second) of Contracts, and from Article 2 of the Uniform Commercial Code as it has been adopted in all fifty states. This edition includes expanded material on the United Nations Convention on the International Sale of Goods, and the UNIDROIT Principles of International Commercial Contracts, appropriate to a basic course in Contracts, and on modern statutes regarding electronic contracting. Understanding Contracts was written with the understanding that Contracts will be one of the most challenging courses first-year law students will take. It explains how key concepts apply in several recurring basic fact patterns. It then builds on those fact patterns to explain how the law is more difficult to apply in business transactions with more complex facts. A key feature of Understanding Contracts, that is not found in other similar books, is its conscious incorporation of basic explanations of the common business practices to which the law of contracts applies. The feature helps students, many of whom have not had any background in the business world, understand contract law in the business settings in which it frequently applies. The book also provides detailed topic headings that students can use to develop their own comprehensive course outline.