The present study aims to examine the jurisprudential and legal foundations of contractual conditions (Shorut-e Zeman Aghd) and analyze the conditions for their validity and nullity. Contractual conditions are considered one of the most significant legal tools for regulating the relationships between parties in contracts and play a crucial role in defining the obligations and responsibilities of the parties. In the Iranian legal system, these conditions are addressed in Articles 232 to 246 of the Civil Code and, conditions of description (Shart-e Sefat), conditions of action (Shart-e Fe'l), and conditions of result (Shart-e Natijeh). In this regard, the opinions of jurists on valid and void conditions, the legal effects of breach of conditions, and the related legal remedies have been analyzed.
The findings of the study show that the two legal systems of Iran deal with contractual terms differently. However, there are similarities in some principles, such as the need to determine specific and enforceable terms. The need to review the laws related to contractual terms, strengthen judicial supervision, provide broader legal education for the public, and use modern technologies in recording and enforcing terms is suggested.