  The sensitivity of the Deep Underground Neutrino Experiment (DUNE) to
neutrino oscillation is determined, based on a full simulation, reconstruction,
and event selection of the far detector and a full simulation and parameterized
analysis of the near detector. Detailed uncertainties due to the flux
prediction, neutrino interaction model, and detector effects are included. DUNE
will resolve the neutrino mass ordering to a precision of 5$\sigma$, for all
$\delta_{\mathrm{CP}}$ values, after 2 years of running with the nominal
detector design and beam configuration. It has the potential to observe
charge-parity violation in the neutrino sector to a precision of 3$\sigma$
(5$\sigma$) after an exposure of 5 (10) years, for 50\% of all
$\delta_{\mathrm{CP}}$ values. It will also make precise measurements of other
parameters governing long-baseline neutrino oscillation, and after an exposure
of 15 years will achieve a similar sensitivity to $\sin^{2} 2\theta_{13}$ to
current reactor experiments.
