The study analyzes the impact of the monetary crisis on legal instruments that has affected Lebanon since August 2019, using concrete examples from daily transactions. It explores the relationship between the crisis and both creditors and debtors new applied methods. The study investigates how new practices designed by creditors and debtors because of the crisis, have affected some of the Lebanese legal instruments whether regarding their role, or with respect to their legal elements specified in law. The paper tested two hypotheses: first, that the crisis has had an impact on legal instruments; and second the role of the legal theory of unjust enrichment as a remedy to the said impact. The methodology of the study is based on secondary date as the study is theoretical basis. The results reveal that the crisis has created critical imbalance between the creditors’ and the debtors’ rights and obligations, due to the absence of new laws to enable Lebanese judges to interfere in the contract and restore the said balance between the contractual parties' rights and obligations as recently applied in other countries. As a result, the study attempts to assess if the theory of unjust enrichment can be used to serve as a legal remedy to compensate creditors subject to injury resulting from the current legal position, which prohibits them from refusing debtors’ payments made in Lebanese pounds (LBP) as per the low official exchange rate. The results show that this theory can be applied in the case of some legal instruments which have been affected by the crisis.