The elastic complex screen, or phase screen approach to the forward modeling of elastic waves promises significant advantages over other computational schemes, because it is potentially much less intensive numerically than finite difference methods, and yet it models essentially the whole useful wave field. In this paper it is shown how the equations that describe the technique can be derived through a geometrical construction. The new formulation is presented in conjunction with an overview of the earlier derivation of Wu <1994> in order to emphasize the similarities and differences between the two approaches. The geometrical derivation provides for a formulation in terms of interfaces (steps) rather than slabs. It also leads quite naturally to the incorporation of backscattered energy in the model. An algorithm to implement this important capability is developed in some detail and includes a backpropagation technique, which improves storage efficiency by removing the need to store the backscattered field at each screen independently. Numerical results are presented for some simple backscattering models, first of all to validate the theory, but then more specifically to illustrate the frequency response of the model and the implications it has for the choice of a suitable source spectrum. ¿ 1998 American Geophysical Union