What is acceptance of an offer?

Acceptance of a contract is the assent of the offeree to the demands contained in the offerors offer. Acceptance of the contract varies depending upon whether the contract is unilateral or bilateral. An offeree accepts a bilateral contract by making the return promise demanded by the offeror. An offeree accepts a unilateral contact by undertaking the performance demanded by the offeror. The acceptance of an offer must meet a specific standard based upon the type of contract and the governing law. The standards that a specific type of contract must meet are as follows:

What is the Mirror-Image Rule?

Contracts that are not primarily for the sale of goods may be governed by rules derived from the Restatement of Contracts. The Restatement proposes the mirror-image rule for acceptance of an offer. This rule states that the acceptance of an offer must be exactly as demanded by the offeror. That is, the acceptance must mirror the offer. If the offeree adds new terms to the acceptance, it is not really an acceptance. Acceptance with different or additional terms constitutes a counteroffer.

• Example: I offer to perform a service for you at a given fee. You reply that my prices are too high and that you want a 15% discount. You changed the terms of the consideration (the price), which is a material aspect of the offer. As such, you have effectively rejected my offer, as your attempted acceptance was not the mirror image of my offer.