  We present a model for the formation of massive ($M > 10 M_\odot$) stars
through accretion-induced collisions in the cores of embedded dense stellar
clusters. This model circumvents the problem of accreting onto a star whose
luminosity is sufficient to reverse the infall of gas. Instead, the central
core of the cluster accretes from the surrounding gas, thereby decreasing its
radius until collisions between individual components become significant. These
components are, in general, intermediate-mass stars that have formed through
accretion onto low-mass protostars. Once a sufficiently massive star has formed
to expel the remaining gas, the cluster expands in accordance with this loss of
mass, halting further collisions. This process implies a critical stellar
density for the formation of massive stars, and a high rate of binaries formed
by tidal capture.
