If a problem arises, a written contract would offer proof of the agreed-upon terms and conditions between the people making the contract (parties). This may be beneficial in a court of law. With some exceptions, a court may not accept evidence about oral terms of the contract if there is a written contract that is complete on its face. Of note, parties are presumed to know the terms and conditions of the contract and what their responsibilities are when they sign the contract. Never sign a contract or other legal document without understanding what it means.