The use of supplemental viscous damping significantly improves the seismic performance of buildings; however, a design procedure that considers seismic risk is necessary. The aim of this article is to simplify the seismic risk assessment of mid-rise steel frames with linear viscous fluid dampers by employing probabilistic models and a reliability analysis. The development of a probabilistic seismic response model (PSRM) to predict the structural response without performing extensive computation is a principal component of this methodology. The design and modeling of generic frames, record selection, cloud analysis, assessment of candidate intensity measures, and use of vector-valued intensity measures are the primary aspects of this study, the goal of which is to put forward a PSRM for the target frames. Comparison of the PSRM outcome with the results of case studies demonstrates the acceptable accuracy of the models for the design earthquake; these models lead to a reduction in the computation and complexity involved in selecting design variables to achieve a target risk.