R2d § 33
Certainty
(1) Even though a manifestation of intention is intended to be understood as an offer, it cannot be accepted so as to form a contract unless the terms of the contract are reasonably certain. (2) The terms of a contract are reasonably certain if they provide a basis for determining the existence of a breach and for giving an appropriate remedy. (3) The fact that one or more terms of a proposed bargain are left open or uncertain may show that a manifestation of intention is not intended to be understood as an offer or as an acceptance.
Professor's notes
Elements: (1) even if a manifestation of intent is intended as an offer, it cannot be accepted so as to form a contract unless the terms are reasonably certain; (2) terms are reasonably certain if they provide a basis for determining breach and for giving an appropriate remedy; (3) the fact that one or more terms are left open or uncertain may show that no offer was intended.
Academy Chicago Publishers v. Cheever operationalizes the rule: anthology agreement failed because the parties never specified which stories. No basis to identify breach, no remedy.
Common misunderstanding: students assume courts will fill gaps. They will (UCC § 2-305 price, § 2-309 time), but only when the parties manifested commitment. Where the indefiniteness goes to whether they ever agreed, gap-filling cannot rescue.
Text
R2d § 33. Certainty.
(1) Even though a manifestation of intention is intended to be understood as an offer, it cannot be accepted so as to form a contract unless the terms of the contract are reasonably certain.
(2) The terms of a contract are reasonably certain if they provide a basis for determining the existence of a breach and for giving an appropriate remedy.
(3) The fact that one or more terms of a proposed bargain are left open or uncertain may show that a manifestation of intention is not intended to be understood as an offer or as an acceptance.