  The Press-Ryden-Spergel (PRS) algorithm is a modification to the field theory
equations of motion, parametrized by two parameters ($\alpha$ and $\beta$),
implemented in numerical simulations of cosmological domain wall networks, in
order to ensure a fixed comoving resolution. In this paper we explicitly
demonstrate that the PRS algorithm provides the correct domain wall dynamics in
$N+1$-dimensional Friedmann-Robertson-Walker (FRW) universes if
$\alpha+\beta/2=N$, fully validating its use in numerical studies of cosmic
domain evolution. We further show that this result is valid for generic thin
featureless domain walls, independently of the Lagrangian of the model.
