As others have mentioned a written contract is a legal binding document, where you have signed pen to paper. Certain clauses allows to you to break from it, but if you there are any agreements in the contract that you go against, it can be held against you. In terms of an oral contract, it can be harder to go to court without any evidence. If you have a recorded conversation, with the persons consent with the person stating their name and that they agree along with the terms and conditions in what they are agreeing to, that would be sufficient evidence in court. However, I know in some states if you record a conversation without a persons consent, the evidence would be dismissible in court.