Learn common breach of contract defenses such as not having it in writing or unclear terms. Find examples of contract defenses with NYC Bar.Plaintiff must submit his or her detailed affidavit of facts together with proof of service of the legal papers upon defendant(s). To form a contract, the plaintiff must establish an offer, acceptance of the offer, consideration, mutual assent and an intent to be bound. An offer is a proposal from one party to another intending to create a legal obligation upon acceptance.