The book proposes the reconstruction of the text "Words about Igor's Regiment" as a monument to ancient Russian poetry. The study is based on the hypothesis that the "Word" is a poetic work consisting of poetic lines with a different number of syllables. Each row has an individual meter; the entire text of the "Word" is stitched with a "ladder" rhyme between adjacent lines. The establishment of a regular metric in the "Word on Igor's Regiment" became possible thanks to the hypothesis (A. Yu. Chernov, A. V. Dybo), according to which the monument presents an optional clarification of the weak reduced. The reconstruction of stress in the "Word" is based on the results of the Late Slavic accentological reconstruction and the data of the Old Russian accentological dictionary of A. A. Zaliznyak (2014). The metric system "Words on Igor's Regiment" can be defined as unequal syllabotonics; the same system is found in some other Old Russian texts.