Encephalomyocarditis virus encodes an accessory protein, 2B*, in an overlapping ORF. 2B* is expressed as a result of protein-stimulated ribosomal frameshifting at the late stages of viral replication (6–8 hpi). 2B* is only found in EMCV, not other picornaviruses, yet 2B* knockout EMCV possesses a small plaque phenotype, indicating it is essential for efficient viral spread. The underlying mechanism for this was entirely unknown. We found that the presence of 2B* causes infected cells to lyse earlier, resulting in heightened extracellular viral titres, whereas 2B*KO viruses are retained within the host cell. This reduced rate of lytic release explains the previously reported small plaque phenotype exhibited by 2B*KO EMCV, despite unaltered rates of RNA replication and ribosomal frameshifting. We also found 2B* to be essential for efficient caspase-3/GSMDE-dependent pyroptosis, and to promote an additional as-yet unidentified, caspase-3 independent lytic pathway. 2B* therefore plays a key role in determining which cell death pathway is utilised during EMCV infection and contributes to the remarkably fast replication cycle of this picornavirus. We also investigated the host interaction partners of 2B* during infection and found that the entire family of 14-3-3 proteins bind to 2B*, via a C-terminal short linear motif. Through this interaction, 2B* impedes both the IFN-β and IL-6 innate immune responses, presumably through a reduction in MAVS signalling. This function is distinct from its role in promoting plaque size via manipulation of the cell death signals, indicating that this previously uncharacterised protein has multiple functions within the viral replication cycle.