Contract law supports and regulates the activity of contract making, and in doing so, supports and regulates the most important aspects of human life: our freedom, our welfare, and our sense of fairness and community. It allows us to project our intentions into the future and plan actions that require concrete pre-commitments. In doing so, it must lay down the rules of contract making—what it is, how we do it, what we can get from it, and what happens when things don't go to plan.

This Very Short Introduction shows how contract law prescribes the conditions for the cooperation and coordination that construct the marketplace by ensuring agreements are voluntary, maintaining reciprocity between parties, and providing remedies when contracts are breached. It describes how the detailed rules governing these functions, and how courts apply them, emerge from a delicate balancing of the five competing values that varies over time and societies: freedom, fairness, community welfare, efficiency, and practical workability. The contemporary challenge is to regulate contract making in the digital environment to protect consumers from exploitation while not stifling the innovation. Contract law reveals the architecture of human cooperation and coordination: how we've learned to trust strangers, coordinate complex activities, and built a global civilization. Understanding contract law means understanding what makes us human.