This study examines how the law of damages in international commercial contracts balances economic efficiency and fairness. Drawing on law-and-economics theory and the frameworks of the United Nations Convention on Contracts for the International Sale of Goods (CISG), the UNIDROIT Principles of International Commercial Contracts (PICC), the Principles of European Contract Law (PECL), and the Draft Common Frame of Reference (DCFR), it employs doctrinal, comparative, and jurisprudential analysis. Findings indicate that these instruments integrate efficiency-based limits, such as foreseeability and mitigation, with fairness-oriented principles of full compensation, though significant divergences persist in practice. The study proposes a six-step evaluative model that systematizes the assessment of damages, aiming to harmonize efficiency and fairness and to enhance predictability in cross-border commerce...