This study focuses on the various playful uses of language that occurred during a semester-long study of two German language courses using one type of synchronous network-based medium, the MOO. Research and use of synchronous computer-mediated communication (CMC) have flourished in the study of second-language acquisition (SLA) since the late 1990s; however, the primary focus has been on the potential benefits of using CMC to increase the amount of communication (Beauvois, 1997; Kern, 1995; Warschauer, 1997), motivate students (Beauvois, 1997; Kern, 1995; Warschauer, 1997) and foster the exchange of ideas (Beauvois, 1997; Kern, 1995; von der Emde, Schneider, & Kotter, 2001; Warschauer, 1997). Only more recently has research within SLA begun to investigate the types of communication that occur online. An analysis of the transcripts from a second-semester German course and an upper-level German communication course reveal that a large portion of the language use online cannot be described using standard referential definitions of communication, but rather is playful in nature. Using research from SLA and theories on social interaction, this article investigates the different types of play that occurred within the online discussions and the possible implications of the presence of play in online discourse. (Contains 11 notes.)