Explanation:

In contract law, there are certain circumstances under which the original contract need not be performed. These circumstances include alteration of contract, recession of contract, and novation. Let's discuss each of these in detail:

1. Alteration of contract:
When there is a change or modification made to the terms of the original contract, it is known as an alteration of contract. This alteration may involve changing the terms, conditions, obligations, or rights of the parties involved. If such an alteration occurs, it can release the parties from their obligations under the original contract. This means that the original contract need not be performed as it has been modified.

2. Rescission of contract:
Rescission of a contract refers to the cancellation or termination of the contract by mutual agreement of the parties involved. When a contract is rescinded, it is treated as if it never existed in the first place. This means that the parties are released from their duties and obligations under the contract. As a result, the original contract need not be performed.

3. Novation:
Novation is a legal concept that involves the substitution of a new contract in place of the original contract. It occurs when all parties to the original contract agree to replace it with a new contract that extinguishes the rights and obligations under the original contract. When novation takes place, the original contract is discharged, and the parties are no longer required to perform their obligations under it.

Conclusion:
In conclusion, the original contract need not be performed if there is an alteration of contract, recession of contract, or novation. These circumstances can release the parties from their obligations under the original contract. It is important to note that these circumstances require the mutual agreement and consent of all parties involved.