A written partnership contract is known as a "deed". A deed is a legal document that is signed and delivered, often used to transfer the ownership of property or legal rights from one person to another. In the case of a partnership, a deed serves as a formal agreement that outlines the terms and conditions of the partnership, including the roles and responsibilities of each partner, the duration of the partnership, and the profit-sharing arrangements. The deed is a legally binding agreement and provides protection to all parties involved in the partnership.