What does the “mirror image rule” state regarding contract acceptance?

The mirror image rule is a fundamental principle in contract law that dictates that for an acceptance to be valid, it must exactly match the terms of the offer. This means that the accepting party cannot modify or change any terms; they must accept the offer as it stands. If the acceptance varies in any way—whether it introduces new terms or alters existing ones—it can be considered a counteroffer rather than an acceptance.

This principle helps ensure clarity and mutual agreement between the parties involved in a contract. It promotes legal certainty by requiring that both parties are in complete accord regarding the terms before a contract is formed. In practical terms, a valid acceptance under the mirror image rule leads to the conclusion of a contract, while any deviation suggests that the parties are not yet in agreement.

The other choices do not align with this principle. For example, the idea that acceptance must have different terms is contrary to the essence of the rule. Similarly, restrictions such as requiring acceptance to be in writing or permitting terms that favor the offeror fall outside the stipulations of the mirror image rule.