This paper explores the use of magnetorheological (MR) dampers for seismic response reduction in civil engineering structures. MR dampers are semi-active control devices that require very low power, making them suitable for seismic applications where external power may be unavailable. The authors propose a clipped-optimal control strategy based on acceleration feedback to control MR dampers, aiming to reduce structural responses due to seismic loads. A numerical example using a newly developed model of an MR damper is presented to demonstrate the effectiveness of the approach. The model accurately captures the salient characteristics of MR dampers, including their high yield strength, low viscosity, and stable hysteretic behavior over a broad temperature range. The clipped-optimal control algorithm is designed to adjust the command voltage of the MR damper to approximate the optimal force level, leveraging readily available acceleration measurements. The results show that the semi-active control system outperforms both passive-off and passive-on control systems, achieving better reduction in peak displacements and accelerations compared to an ideal active control system. The study highlights the potential of MR dampers in seismic response reduction, offering a promising solution for civil engineering structures.This paper explores the use of magnetorheological (MR) dampers for seismic response reduction in civil engineering structures. MR dampers are semi-active control devices that require very low power, making them suitable for seismic applications where external power may be unavailable. The authors propose a clipped-optimal control strategy based on acceleration feedback to control MR dampers, aiming to reduce structural responses due to seismic loads. A numerical example using a newly developed model of an MR damper is presented to demonstrate the effectiveness of the approach. The model accurately captures the salient characteristics of MR dampers, including their high yield strength, low viscosity, and stable hysteretic behavior over a broad temperature range. The clipped-optimal control algorithm is designed to adjust the command voltage of the MR damper to approximate the optimal force level, leveraging readily available acceleration measurements. The results show that the semi-active control system outperforms both passive-off and passive-on control systems, achieving better reduction in peak displacements and accelerations compared to an ideal active control system. The study highlights the potential of MR dampers in seismic response reduction, offering a promising solution for civil engineering structures.