Lead halide perovskites have emerged as highly efficient solar cell materials. However, to date, the most promising members of this class are polymorphs in which a wide-band-gap δ phase competes with the photoactive perovskite α form and the intrinsic physical interactions that stabilize one phase over the other are currently not well understood. Classical molecular dynamics simulations based on suitably parametrized force fields (FF) enable computational studies over broad temperature (and pressure) ranges and can help to identify the underlying factors that govern relative phase stability at the atomic level. In this article, we present a force-matching-based approach for the automatized generation of polarizable (