In this talk I review methods of BRST quantization and it's extension to the Batalin-Vilkovisky anti-field formalism, I then apply this to the context of quantum gravity and explain how these methods can be used to incorporate diffeomorphism invariance at the quantum level. I then expand upon this and elucidate how several gradings can be used to produce actions order by order in the gravitational coupling which are highly restricted, applications of cohomological methods and BRST exact terms will also be discussed. The slides can be found here.