Accord and Satisfaction may be used as an illustration. The resource contains a definition of accord and satisfaction, the elements, and the burden of proof. This is followed by specific examples of accord and satisfaction.
Here is a description of accord and satisfaction from an old Iowa case to demonstrate what is required (definition, elements, and burden of proof) of a plaintiff.
But as an accord and satisfaction is an executed agreement whereby one of the parties undertakes to give, and the other to accept, in satisfaction of a claim arising either from contract or tort, something other or different from what he is or considers himself entitled to, no invariable rule can be laid down, with any degree of certainty, as to what constitutes such an agreement. Each case must be determined largely on its peculiar facts. To constitute a valid accord and satisfaction, not only must it be shown that the debtor gave the amount in satisfaction, but that it was accepted by the creditor as such.… The agreement need not be express, but may be implied from circumstances, as shown in the cases just cited. Where an offer of accord is made on condition that it is to be taken in full of demands, the creditor, doubtless, has no alternative but to refuse it or accept it upon such conditions.
Perin v. Cathcart, 115 Iowa 553, 557-58, 89 N.W. 12, 13 (1902).