  Optical flares have been observed from magnetically active stars for many
decades; unsurprisingly, the spectra and temporal evolution are complicated.
For example, the shortcomings of optically thin, static slab models have long
been recognized when confronted with the observations. A less incorrect -- but
equally simple -- phenomenological $T \approx 9000$ K blackbody model has
instead been widely adopted in the absence of realistic (i.e.,
observationally-tested) time-dependent, atmospheric models that are readily
available. We use the RADYN code to calculate a grid of 1D
radiative-hydrodynamic stellar flare models that are driven by short pulses of
electron-beam heating. The flare heating rates in the low atmosphere vary over
many orders of magnitude in the grid, and we show that the models with
high-energy electron beams compare well to the global trends in flux ratios
from impulsive-phase stellar flare, optical spectra. The models also match
detailed spectral line shape properties. We find that the pressure broadening
and optical depths account for the broad components of the hydrogen Balmer
$\gamma$ lines in a powerful flare with echelle spectra. The self-consistent
formation of the wings and nearby continuum level provide insight into how
high-energy electron beam heating evolves from the impulsive to the gradual
decay phase in white-light stellar flares. The grid is publicly available, and
we discuss possible applications.
