How may the Discharge of Contracts be happened?

•  Most contracts are discharged by full performance. Contracts may also be discharged by

(1) agreement,
(2) impossibility or impracticality,
(3) alteration of a written contract, and
(4) breach of contract.

•  When the contract is essentially complete, the courts may permit the party who performed to recover on the basis of substantial performance.

•  A discharge by agreement involves
(1) mutual agreement,
(2) rescission,
(3) novation, or
(4) accord and satisfaction.

•  For the following reasons, contracts may legally be discharged under the doctrine of impossibility
(1) destruction of the subject matter,
(2) death or serious illness in a personal services contract, or
(3) change in the law. Under the common law, if performance simply becomes more difficult to perform (but performance is still possible), no relief is automatically granted. Under modern law, however, the doctrine of commercial impracticability becomes the basis for justifiable nonperformance in selective cases.

•  If one party to a contract deliberately makes a material change in its terms without the permission
of the other party, the contract is discharged.