The dynamic game theory model developed previously for asexual organisms is extended to randomly mating diploid populations where the strategy used is determined by a single locus. Any number of strategies may be considered in the model, but only the case of hierarchical dominance is treated. An algorithm is given for determining all equilibria in any given game, and for checking these equilibria for local stability. Many of the stability properties found in our previous paper for asexual populations also apply to diploid populations, but, in contrast to asexual populations, diploid populations with no evolutionarily stable points (ESPs) can exhibit stable oscillations.