The hope of the businesses that a signed contract would bring certainty and clarity proved illusory. As the contracting parties are free to employ any means of communication, a party not willing to continue with the contract could simply assert the existence of further collateral oral or written agreements. The response to this challenge has been in the insertion of an entire agreement clause. The clause seeks to exclude everything outside the signed contract by insisting that all representations and agreements outside the written signed document are extinguished. The clause has unfolded to pose newer challenges. Does it mean that all the misrepresentations are also extinguished, vacating the right of a party against misrepresentation? The chapter explores entire agreement clauses and its unfolding by the courts.