Based on the results of 267 replication experiments with obsidian, chalcedony, and agate tools conducted with a range of working materials, I have classified use-wear patterns using Keeley's high-resolution approach to establish a framework for interpretation of stone-tool use. This paper describes the results of microwear analysis of two assemblages of lithic artifacts from the late Late Classic period (A. D. 763-850) at Copán, western Honduras, and shows how the use-wear data can be interpreted within the archaeological contexts and help to investigate how ancient complex societies functioned as well as how and why they changed. Microwear analysis of chipped-stone artifacts collected in front of Structure 10L-16 and artifacts from Structure 10L-22A show clear differences between the two assemblages. In accordance with the archaeological, epigraphic, and iconographic evidence, the low use-intensity of chipped stone from the first structure could have originated from special use such as ritual, production of marine shell ornaments, etc., during the reign of Yax Pac. Marine shell craft production may have been carried out by members of the royal family or attached specialists serving the ruler. The relatively high use-intensity observable in the second assemblage may reinforce the hypothesis that the building was a Classic Maya popol na (council house) in which feasts or banquets were prepared. If this was the case, use-wear data might support epigraphic and iconographic evidence that suggests the weakening and eventual demise of centralized political authority at Copán in the ninth century.