A 'warped conformal field theory' is a field theory in 1+1 dimensions
invariant under a chiral scaling symmetry that acts only on right-movers.
The symmetries differ from an ordinary CFT, but for some purposes provide
equally powerful constraints. I will discuss their thermodynamics, purely
within 2d field theory. Then, motivated by the fact that the near horizon
geometry of every extremal black hole has the same symmetries as a
warped conformal field theory, I will describe an application to the
calculation of black hole entropy in quantum gravity.