The rules of person agreement in Dargwa (East Caucasian) are quite complex and are based on the relative positions of core arguments on the person hierarchy and the grammatical relations hierarchy. These rules also vary across languages of the group. In contrast, gender agreement generally occurs only with the absolutive case argument. In this chapter, it is demonstrated that the variation between the agreement systems of individual Dargwa languages is adequately described if a two-level clause structure is adopted, where person agreement is determined at the upper level. The terms «person» and «gender» agreement should be treated as mere labels for Dargwa languages, because both «gender» markers may reflect person features, and, conversely, «person» markers often include a gender marker. From the syntactic point of view, the controller of «person» agreement is freely identified with either A or P. The choice of the eventual controller is instead determined not by syntax proper, but by a set of postsyntactic Optimality-Theoretic constraints. Therefore, the same f-structure may correspond to different c- and f-structure pairs in different dialects, which allows one to uniformly describe interdialectal variation and enumerate the logically possible types of agreement systems in Dargwa.