Finite-element models of passive-roof duplexes simulate the evolution and distribution of fault slip and deformation as functions of boundary conditions, friction on the roof fault, cover strength and amount of overburden. A foreland buttress is essential for backthrust displacement in the models. This foreland buttress is analogous to a pin line between the cover and footwall forelandward of the triangle zone in a balanced cross section, and could be caused by a stratigraphic pinchout of the upper detachment or a strong cover in the foreland. With boundary conditions that prevent the cover from slipping toward the hinterland relative to the wedge, incipient forethrust and backthrust ramps (zones of high equivalent plastic strain) cut through the cover. In the models, there is more backthrust displacement with a lower friction coefficient on the upper detachment and with a stronger cover. Because of pressure dependence, both fault strength and material strength increase with increasing overburden. Therefore, the effect of overburden on backthrust displacement is determined by the nature of the pressure dependencies for fault friction and material strength. In models with multiple imbricate faults, the distribution of equivalent plastic strain adjacent to each fault is similar to that in single-fault models, with differences resulting from bending strains in the wedge and cover. The strain distribution in the cover of the models is similar to that above natural passive-roof duplexes, characterized by layer-parallel shortening above the tip of each horse in the duplex.