The fourth volume of the DIGAREC Series holds the proceedings to the conference “Logic and Structure of the Computer Game”, held at the House of Brandenburg- Prussian History in Potsdam on November 6 and 7, 2009. The conference was the first to explicitly address the medial logic and structure of the computer game. The contributions focus on the specific potential for mediation and on the unique form of mediation inherent in digital games. This includes existent, yet scattered approaches to develop a unique curriculum of game studies. In line with the concept of ‘mediality’, the notions of aesthetics, interactivity, software architecture, interface design, iconicity, spatiality, and rules are of special interest. Presentations were given by invited German scholars and were commented on by international respondents in a dialogical structure.