In our digitalizing world, interactions of any kind (professional, educational, recreational etc.) can take place in a digitally mediated setting or even a (partially) virtual environment. Acting in a virtual space therefore leads interactants to a special perception and usage of their action environment as well as their perception of themselves (e.g. Wasson, 2006; Keating & Sunakawa, 2010). Jucker et al. (2018) argue that space is an interactive achievement, and by analyzing the use of different multimedia online-settings, they show that screen-mediated interaction has different spatial and therefore referential dimensions between which an interactant constantly navigates. In our talk, we will address the question of how players of a cooperative three-player online serious game construct and use the common action space of the game platform as an interactive achievement. In the game, the players are in a drowning submarine and have to repair some damages. They can see each other's talking head representations (Morel & Licoppe, 2009) within the game interface via webcam, hear each other and use an integrated chat. At the end of each turn, water flows into the different rooms and increases the difficulty: when a certain water level is reached, the game is lost. They play turn by turn and embody three complementary roles associated with different powers, each being essential in the game scenario. This asymmetry makes it necessary to communicate, share information and jointly make decisions on the strategy to choose. To do so, the players need a common understanding of and reference to the action space in the game. Therefore, in our analysis we will show 1) how the players build a common referential framework, treating each player's different origo (Bühler, 1934) and how they manage the resulting asymmetries and inevitable "deixis-related trouble" (Arminen et al., 2016: 297). They do so notably through the use of verbs expressing perception (mostly visual) and verbs of movement in space which allow the other players to monitor otherwise inaccessible information of ongoing action. 2) how they make use of the affordances of the technical device to show their engagement in the game as the common action space, for example to achieve joint attention through phygital highlighting (Due & Toft, 2021) despite their physical distance. In addition to that, we will focus on the comparison of two different game conditions: C1 being the condition where the active player has an immersive first person view while the inactive players have an overall third person view of the game board and C2 where all the players have the overall game board view all the time. We will notably show how the supplementary epistemic asymmetry concerning spatial perception created in C1 influences the interaction with the game as well as with the other players in opposition to C2. The verbal and multimodal interaction between the participants, captured with audiovisual screenshots and videos of the participants' webcams during the whole game interaction, will be analyzed with the methodological tools of conversation analysis and interactional linguistics (CA/IL). They will be augmented with information about the participants' interaction with the game interface (human-computer interaction, HCI) provided by log data (digital traces) from the game platform. Combining these two data sources allows us to do a very fine-grained sequential analysis of the actions that take place on the participants' screens as well as in their physical environment, even though we are limited to what their webcams show. Those details play an important role when we want to get an insight into the perception and use of space and environment, especially the participants' navigation between the different spatial layers (the "real world" physical environment, the webcams, the virtual space of the submarine, the screen) in this complex configuration. References : Arminen, I., Licoppe, C., & Spagnolli, A. (2016). Respecifying Mediated Interaction. Research on Language and Social Interaction, 49 (4), 290 309. https://doi.org/10.1080/08351813.2016.1234614 Bühler, Karl (1934): Sprachtheorie: Die Darstellungsfunktion der Sprache, Stuttgart/New York. Fischer. Due, B. L., & Toft, T. (2021). Phygital highlighting : Achieving joint visual attention when physically co-editing a digital text. Journal of Pragmatics, 177, 1 17. Ibnelkaïd, S. (2016). Identité et altérité par écran : Modalités de l’intersubjectivité en interaction numérique [Thèse de doctorat, Linguistique, Université Lumière Lyon 2]. https://tel.archives-ouvertes.fr/tel-01364790/document Jucker, A. H., Hausendorf, H., Dürscheid, C., Frick, K., Hottiger, C., Kesselheim, W., Linke, A., Meyer, N., & Steger, A. (2018). Doing space in face-to-face interaction and on interactive multimodal platforms. Journal of Pragmatics, 134, 85 101. https://doi.org/10.1016/j.pragma.2018.07.001 Keating, E., & Sunakawa, C. (2010). Participation cues: Coordinating activity and collaboration in complex online gaming worlds. Language in Society, 39 (3), 331 356. Licoppe, C. (2017). Showing objects in Skype video-mediated conversations: From showing gestures to showing sequences. Journal of Pragmatics, 110, 63 82. Morel, J., & Licoppe, C. (2009). La vidéocommunication sur téléphone mobile - Quelle mobilité pour quels cadrages ? Réseaux, 4 (156), 165 201. Wasson, C. (2006). Being in Two Spaces at Once. Journal of Linguistic Anthropology, 16 (1), 103 130.