We investigate quantum phenomena in a system of three coupled microcavities each supporting regime of strong coupling with exciton resonance. The possibility of observing a polariton blockade in a dimer and trimer configuration is discussed. We identify the resonance conditions corresponding to the onset of the photon blockade. The discovered quantum effects allow for using these systems as versatile sources of individual polaritons. Various manifestations of the quantum blockade can be tuned with the use of the pumping laser frequency. We demonstrate that the presence of the complex coupling between the pillars enhances manifestations of sub-Poissonian statistics of polaritons.