  We consider one-round games between a classical verifier and two provers who
share entanglement. We show that when the constraints enforced by the verifier
are `unique' constraints (i.e., permutations), the value of the game can be
well approximated by a semidefinite program. Essentially the only algorithm
known previously was for the special case of binary answers, as follows from
the work of Tsirelson in 1980. Among other things, our result implies that the
variant of the unique games conjecture where we allow the provers to share
entanglement is false. Our proof is based on a novel `quantum rounding
technique', showing how to take a solution to an SDP and transform it to a
strategy for entangled provers. Using our approximation by a semidefinite
program we also show a parallel repetition theorem for unique entangled games.
