Purim is already, in its biblical source, a story unusually suited to theatre: the Book of Esther is built on reversal, disguise, mistaken favour and a villain hoisted by his own plot, and it is also, notably among the books of the Hebrew Bible, one in which God is never named directly, a silence later commentators read as inviting the reader, or the audience, to see divine providence working through entirely ordinary human intrigue rather than open miracle. The Purim spiel grew from that material into a genre of its own in medieval and early modern Ashkenazi communities, staged theatrical or semi theatrical performances retelling or parodying the Esther story, traditionally performed by young men, students or amateur troupes going house to house or performing at community gatherings during the days around the holiday.
Purim's wider customs of costume, masking and the rabbinically sanctioned relaxation of ordinary restraint, most famously the Talmudic saying that a person should drink on Purim until unable to distinguish the villain Haman from the hero Mordecai, created a licensed space for exactly the kind of topsy turvy performance the spiel represents, dramatic parody flourishing precisely because the holiday itself already authorised a period of sanctioned foolery within an otherwise serious religious calendar.