The present study aims at interpreting a Sumerian hymn pertaining to the cult of the ancient Mesopotamian goddess of love and war, Inanna/Ištar. Though this literary composition belongs to the realm of royal religion, and centres on the relationship between the goddess and the royal personage, the hymn also provides an insight into a cultic feast of rather popular character. The text describes a ritual; its inner logic follows the course of a cultic ceremony. Accordingly, the term "implicit ritual" as opposed to "explicit ritual", or liturgical order, can be applied. Until now the Sumerian hymn in question has been treated mainly from a text critical point of view. Certain aspects of the ritual performance, viz. the playful change of gender roles, are expressed through the epithets of the goddess. Recently, attention has been given to those epithets that allude to the power of the goddess to change her sex, and it has been proposed that they show a shamanistic side of the goddess. In what follows we shall put forward an alternative interpretation of the change of gender roles by using the concept of play and game as intrinsic to a religious system. The cultic feast of the goddess Inanna/Ištar will thus be traced back to a ritual of inversion which serves to reconstitute the moral and social order as well as to consolidate religious belief. Since our hymn is considered to be one of the main sources for the reconstruction of the so-called "sacred marriage" we shall also touch upon this ancient rite.