  Three dimensional hydrodynamic simulations of full amplitude RR Lyrae stars
have been computed for several models across the instability strip. The three
dimensional nature of the calculations allows convection to be treated without
reference to a phenomenological approach such as the local mixing length
theory. Specifically, the time dependent interaction of the large scale eddies
and the radial pulsation is controlled by the conservation laws, while the
effects of smaller convective eddies are simulated by an eddy viscosity model.
The light amplitudes for these calculations are quite similar to those of our
previous two dimensional calculations in the middle of the instability strip,
but somewhat lower near the red edge, the fundamental blue edge, and for the
one first overtone model we computed. The time dependent interaction between
the radial pulsation and the convective energy transport is essentially the
same in three dimensions as it is in two dimensions. There are some differences
between the light curves between the two and three dimensional simulations,
particularly during decreasing light. Reasons for the differences, both
numerical and physical are explored.
