The institution of retrial is established as an exceptional legal mechanism within judicial systems, designed to annul final judgments that have been erroneously issued, with the overarching goal of realizing substantive justice and preventing the perpetuation of unjust judicial decisions. In Iranian law, one of the most significant, yet complex, grounds for retrial is "contradiction in the contents of a judgment", explicitly stipulated in Clause 3 of Article 426 of the Code of Civil Procedure. The central inquiry of this research is to provide a precise elucidation of the concept, delineate the scope of application, and identify the essential conditions required for the realization of this specific legal ground for retrial.
The findings of the research demonstrate that "contradiction in the contents of a judgment" denotes a situation where an inherent and irreconcilable inconsistency exists within the fabric of a single judgment, rendering any conventional or logical harmonization between its constituent parts practically impossible.
Regarding its personal and substantive scope, this ground for retrial is applicable only to final civil judgments and, in the criminal sphere, to judgments pertaining to blood money and financial compensation for damages. Ultimately, the successful invocation of this retrial ground is contingent upon several fundamental conditions: the decision must qualify as a substantive judgment, it must have attained finality, the contradiction must be internal to a single unified judgment, and, most critically, there must exist an "irreconcilable contradiction" within its contents that cannot be resolved through interpretation.