  Gamma rays from the annihilation of dark matter particles in the Galactic
halo provide a particularly promising means of indirectly detecting dark
matter. Here, we demonstrate that pronounced spectral features at energies near
the dark matter particles' mass, which are a generic prediction for most
models, can significantly improve the sensitivity of gamma-ray telescopes to
dark matter signals. We derive projected limits on such features (including the
traditionally looked-for line signals) and show that they can be much more
efficient in constraining the nature of dark matter than the model-independent
broad spectral features expected at lower energies.
