was codified by the American Law Institute as Section 205 of the Restatement (Second) of Contracts.

Most U.S. jurisdictions view the breach of the implied covenant of good faith and fair dealing solely as a variant of breach of contract, in which the implied covenant is merely a "gap-filler" that expresses an unwritten contractual term that the parties would have included in their contract had they thought about it. As a result, a breach of the implied covenant generally gives rise to ordinary