This chapter presents advanced methodologies for structural simulations of concrete dams under seismic loading, with emphasis on verification and validation, uncertainty quantification, and probabilistic seismic analysis. The chapter addresses key sources of uncertainty—including material properties, modeling assumptions, and ground motion input—and offers structured approaches for their quantification. Sensitivity analysis techniques are introduced to identify dominant parameters influencing dam response. Building on this, the chapter explores probabilistic methods for seismic analysis.