Accidentalia is a Latin word which means “accidental things.” In a contract it refers to those elements of a contract that has been omitted by accident. It is the opposite of the word essentialia. Accidentalia are those facts which need to be proved as they cannot be presumed from the existing facts of the case. Accidentalia can be added to the contract by the act of the party. For example if a party to the contract fails to add the element of right of pre-emption in the contact, then the parties can add such element to the contract subsequently. However, omission of essential elements of contract cannot be cured for accidentalia.