In the Calderonian auto, worship and festival unite in playful allegory to celebrate the sacrament of the Holy Eucharist. Play manifests itself in the auto on three levels: in the characteristics of theatrical art in general, in the playful variations of the autos on the primary theme of the genre, and in the transgressive, supplementary play of sin within each auto. Sin's exuberant freedom within the autos, and the multi-tiered workings of play throughout the creation and performance of the allegories, argue against over-interpreting the scope of meta-allegory in the autos. I conclude by stressing that the dual nature of allegory should remain foremost in considering the autos. Because play takes such a fundamental role in the autos, the texts must not be shackled to a logocentric vision of meaning and held to strict readings of their allegories. Rather, they should be appreciated as carefully blended mixtures of sacred worship and secular play, where sin plays freely alongside the promise of salvation, and multifarious meaning springs out of ostensibly arid allegory.