What are the essentials and legal rules for valid offer?

A valid offer must contain clear terms, indicating the offeror's intention to be bound by those terms upon acceptance. It should be communicated to the offeree, and it must be definite enough that the parties can ascertain its essential elements, such as subject matter, price, and time of performance. Additionally, the offer must be made with the intention to create a legal obligation, and it must not be revoked before acceptance. Lastly, the offer must comply with any relevant legal requirements, such as capacity and legality of the subject matter.