Rental contracts are agreements between and landlord and a tenant... they do need to be in writing, but there is no legal requirement that they be notarized or prepared by an attorney in order to be a legal document.  As long as they meet the basic requirements of a contract-- essentially "something for something," they will be a binding legal contract.  Tenants do have certain rights in the state of Texas, and a landlord cannot make a tenant waive those rights. Texas recognizes oral contracts as well, but oral contracts are strongly discouraged because they are more difficult to enforce.