This conceptual paper critiques the popular Community of Inquiry framework (CoI) that is widely used for studying text-based asynchronous online discussion (Garrison, Anderson, & Archer, 2000). It re-examines the three main aspects of CoI (cognitive presence, social presence, and teaching presence) and their relationship, and further highlights the specificity and complexity of online discussion forums. The paper explains that the multi-functionality of communicative acts which often combine instruction, knowledge construction, and social interaction in a single utterance. It further argues that all online expressions are inherently social. It clarifies the confused relation of cause and effect in CoI and specifies the leadership functions of teaching presence and how they are intertwined with social and cognitive presence. A game metaphor and Gadamer's notion of "play" are employed to explain the dynamics of online discussion forums. The article concludes with a discussion of the practical and methodological implications of its main arguments. (Contains 1 table and 2 figures.)