Summary: In [Branched polymers and dimensional reduction, Ann. Math. (2) 158, 1019–1039 (2003)] we have proven that the generating function for self-avoiding branched polymers in \(D+2\) continuum dimensions is proportional to the pressure of the hard-core continuum gas at negative activity in \(D\) dimensions. This result explains why the critical behavior of branched polymers should be the same as that of the \(i\varphi^3\) (or Yang-Lee edge) field theory in two fewer dimensions (as proposed by G. Parisi and N. Sourlas [Phys. Rev. Lett. 46, 871–874 (1981)]. In this article we review and generalize our results of [loc. cit.]. We show that the generating functions for several branched polymers are proportional to correlation functions of the hard-core gas. We derive Ward identities for certain branched polymer correlations. We give reduction formulae for multi-species branched polymers and the corresponding repulsive gases. Finally, we derive the massive scaling limit for the 2-point function of the one-dimensional hard-core gas, and thereby obtain the scaling form of the 2-point function for branched polymers in three dimensions.