Motion of the lithospheric plates is a manifestation of convection in which the plates themselves play a major role. The relative importance of various forces acting on the plates is evaluated by allowing each potentially important force to have an unknown sign and magnitude that is solved for by requiring that each plate be in static equilibrium. This is done by adopting rules that allow determination of the orientation of each force at any point on the bottom or edge of a plate, given information concerning the motion of the plate with respect to its neighbors and to the hot spot reference frame. At each boundary having intermediate and/or deep focus earthquakes a force is input that is due to the negative buoyancy at the descending slab, the stress in the slab shown by first-motion solutions being taken into account. This input force allows a sign and magnitude to be determined for each of the other forces through the torque balance requirement for equilibruim. As an illustration of the degree of balance attained, the residual unbalanced torque on the Pacific plate is only 2.7 to 4.7% of the torque from pull of its cold slabs, depending on the number of forces used in the model. The principal result of many solutions is that the large negative buoyancy forces are counterbalanced by strong local resisting forces at converging boundaries. Resisting drag under continents and net pull toward trenches on upper plates are small but significant. The force exerted by ridges is consistently a very small push. Varying the number of forces in the model from 3 to 10 shows that inclusion of other forces has no significant effect on the quality of the torque balance. Push from hot spots, resistance at transform faults, and drag number oceans do not exert significant torques on the plates.