In jurisprudential and legal terminology, “Gharar” (uncertainty) refers to a situation where one of the counterparts in an exchange is subject to risk due to ambiguity in its essential characteristics or the opposing consideration. Under conditions of opacity regarding essential characteristics, the financial and economic equilibrium in the flow of trade between the counterparts in commutative contracts becomes questionable and, consequently, endangered. Thus, it might be assumed that Gharar is distinct from contractual ambiguities residing in factors external to the counterparts, such as the “term (Ajal)” or duration specified in contracts. However, this assumption is flawed; ignorance of the term (“Jahl al-Ajal”), where it directly or indirectly influences the economic value of the counterparts, can be transferred to the subject matter itself, rendering it indeterminate and giving rise to Gharar in the transaction. In this regard, contractual terms that affect the value of the counterparts—either directly or indirectly—are considered sufficient to dispel Gharar as long as they are deemed certain by Custom (“Urf”); excessive strictness beyond this criterion should be avoided. Nevertheless, ambiguity in contractual terms is considered a cause of Gharar if the risk arising from such ignorance is significant (“Mo'tan-beh”) from a customary perspective. Ultimately, varying interpretations of Custom today have led to a divergence of opinions in both theory and judicial practice regarding the identification of specific, fixed, and thus Gharar-free contractual terms. Utilizing an analytical method and data gathered from library and digital resources, this research explores the legal rulings, analyzes them, and proposes practical solutions.