The criteria for determining contractual damages represent one of the main aspects of contract law. In legal systems where there are no rules imposed by the legislature, reasonable principles are followed to determine the amount of damage that compensates for the sacrifice of the party that suffered the breach of contract. In systems where civil codes provide specific rules, their interpretation is discussed, considering that the formulas used are geneneral or even vague. The projects of harmonization of contract law see this as a crucial issue, and rely on mixed models. The philological reconstruction of the texts, their translation into conceptual terms, are therefore an important key to understand the choices made by the interpreters and...