A contract is only legally binding if it is mutually beneficial to both parties involved. This is commonly referred to as consideration. When a party promises to do something without getting something in return, the deal will usually be unenforceable in court.
Ing to Boundy (2012), typically, a written contract will include: Date of agreement. Names of parties to the agreement. Preliminary clauses. Defined terms. Main contract clauses. Schedules/appendices and signature provisions (para. 5).