A quantitative description of time-dependent magnetohydrodynamics (MHD) intermediate shocks is formulated. In non-coplanar Riemann problems, time-dependent 2 → 3 intermediate shocks evolve in time as a localized self-similar structure whose strength decreases as 1/√t, and whose width expands as √t. We derive structural relations, similar to Rankine-Hugoniot relations, between the plasma properties and the magnitude of the transverse magnetic field, which we hope can help identify time-dependent 2 → 3 intermediate shocks at the magnetopause, in the solar wind, and elsewhere in space. The analytic forms of the structural relations agree with our numerical results. ¿ American Geophysical Union 1992