We present a deformable Gay-Berne (DGB) pair potential for ellipsoidal particles that allows for dynamic fluctuations in their shape and interaction anisotropy. We investigate the effect that various intrinsic distributions of shape and interaction parameters have on the liquid crystal phases formed by a system of DGB particles. We show that deformability can stabilise smectic formation and that all mesomorphic phase transitions are accompanied by a change of molecular shape. (c) 2006 Elsevier B.V. All rights reserved.