Abstract Participants in institutional interaction orient themselves both verbally and non-verbally to the institutional task to be fulfilled. Often the mode for this interaction is neutral, devoid of expressing affect, including humor. However, participant occasionally departs from the basic mode of the encounter. We will discuss cases in which customers at Finnish convenience stores express a playful stance towards buying lottery tickets, departing from the more usual, serious way of interacting. We will concentrate on a highly conventionalized way of being playful at convenience stores: invoking the frame of another type of institutional encounter when presenting one's reason for a visit. We will show that the central means for doing this are interdiscursive lexical choices. The central frame invoked is that of an office; other frames include the investment world and interacting at a hot dog stand. We will argue that the parallel between the encounters in the frame shift is clearly recognizable, resting on the inferences from one's everyday experiences and cultural knowledge. The frame shift (re)contextualizes not only the convenience store encounter, but also the invoked encounter (e.g. applying for pension). We suggest that the motivations for playfulness have to do with the recurrent nature of the activity and a possible delicacy involved in playing the lottery.