A promise is enforceable by law, even if made without formal consideration when a promisor had made a promise to a promisee who then relies on that promise through some action
Ex: I bought dog food, but you decided not to buy a dog

Contracts that are binding when the requested task/performance is given, the offeror cant revoke the offer if the offeree had made substantial performance

1. Agreement to agree
-agreed on most terms, but leave a few factors for future meetings
2. Formal Contract Contemplated
-Agreed on major issues, but contemplate later formal writing

i. Normally- Parties cannot introduce evidence of a prior or contemporaneous agreement in order to modify, explain, or supplement the contract at issue
BUT!!!
ii. If the contract terms are ambiguous parol evidence is allowed to understand intent

1.$500
2. Formal Written Contract

Mailbox Rule

the parties have intended to make a contract, and there is reasonable certainty of appropriate remedy

Consideration
Written expressed assent