Genetic and Behavioural Patterns in Al-Xaliilian Metrics research-article Bello S. Y. al-Hassan Zeitschrift der Deutschen Morgenländischen Gesellschaft, Jahrgang 170 (2020), Ausgabe 2, Seite 309 - 328 Al-Xaliilian Metrics has enjoyed attention and influence both as a cultural and an intellectual matter. For instance, it has been an object of cross-systemic comparisons and theoretical (re)interpretations. Subsequently, the system is either viewed from the angle of that of another poetic tradition or (re)analyzed in the context of some sophisticated linguistic perspective. In either case, the actual focal point may (inadvertently) not be Al-Xaliilian Metrics itself. The current theory casts its gaze single-mindedly on Al-Xaliilian Metrics, demonstrating that it is a self-sustained and self-explanatory mechanics, the internal structure of whose pivotal feature, the foot, determines interactive behaviour within the system. Constitution determines which foot can(not) repeat, or combine or do both and why. The theory unveils Al-Xaliilian metrics as a rigidly segregated, contrast-driven social system, in which genetics, generation and social class ascribe to feet their competencies as prosodic actors. The behaviour of feet within Al-Xaliilian Metrics is reminiscent of that of humans in society. Seventeen rules have been identified as sustaining the system.