This chapter describes three defects in the traditional strict liability paradigm of contract law to demonstrate how fault significantly shapes contract law. First, justifications for strict liability focus on implementing contractual intent when contract law's main focus is interpreting contractual intent. Fault helps interpret contractual intent. Second, the strict liability paradigm excessively emphasizes a single fault variable – the ability of the promisor to control his own performance – and downplays other relevant fault variables. In particular, the strict liability paradigm ignores the potential for opportunistic behavior by the promisee, which creates a “negligence-opportunism trade-off.” A broader conception of fault emphasizes the potential for fault by both parties and the need to make relative fault assessments. Third, the strict liability paradigm overlooks doctrinal avenues in contact law that incorporate fault. One important example is the law of contract damages. Fault helps explain contract damages doctrine.