A Practice Note discussing the discharge of contractual duties by novation, accord and satisfaction, and substituted contract. This Note reviews the elements of each of these methods in the context of commercial transactions under common law and the Restatement (Second) of Contracts. This Note also includes a discussion of full-payment checks under Section 3-311 of the Uniform Commercial Code (UCC), as well the difference between novation and assignment and between a substituted contract and an accord and satisfaction. This Note also provides practical examples and links to relevant Standard Documents.