In this book we will reveal the rules of contract law in as straightforward and clear a fashion as they permit. But we will also talk some about policy and the difference between the two. Policy reflects the normative objectives we want to attain, and the rules are the vehicles for getting us there. In this book, we are going to break the subject of contracts into seven short questions: 1. Has a deal been made? 2. Is the deal enforceable? 3. Are there defenses to enforcement of the deal? 4 What are the terms of the deal? 5. When will performance of the deal be excused? 6. How does the law enforce the deal? 7. Who else is affected by the deal? Once you can answer these questions, you will have mastered contract law.
David G. Epstein & Bruce A. Markell, A Short and Happy Guide to Contracts (2012).