While it is assumed by most critics that IF works are games, few have gone on to consider the nature of "games" closely, or describe what sort of game IF works actually are. There has been little discussion of whether "game" and "puzzle" are truly essential to the form. Tension between game and narrative aspects of a work may explain certain problems inherent in the form, or these two aspects may be discernible elements of a unified work, as seen in some of the best examples of interactive fiction. . . . The riddle serves as the central figure for understanding the workings and poesis of interactive fiction within a tradition that is literary and also demands explicit engagement.