  Low mass star formation regions are unlikely to fully populate their initial
mass functions, leading to a deficit of massive stars. In binary stellar
populations, the full range of binary separations and mass ratios will also be
underpopulated. To explore the effects of stochastic sampling in the integrated
light of stellar clusters, we calculate models at a broad range of cluster
masses, from 10^2 to 10^7 M_sun, using a binary stellar population synthesis
code. For clusters with stellar masses less than 10^5 M_sun, observable
quantities show substantial scatter and their mean properties reflect the
expected deficit of massive stars. In common with previous work, we find that
purely stochastic sampling of the initial mass function appears to
underestimate the mass of the most massive star in known clusters. However,
even with this constraint, the majority of clusters likely inject sufficient
kinetic energy to clear their birth clusters of gas. For quantities which
directly measure the impact of the most massive stars, such as N_{ion},
xi_{ion} and beta_{UV}, uncertainties due to stochastic sampling dominate over
those from the IMF shape or distribution of binary parameters, while stochastic
sampling has a negligible effect on the stellar continuum luminosity density.
