Figure 3 shows the class diagram of scene classes in Astero bots. The Scene, Abstract Scene an Command Base Scene interface or classes provide basic features for representing game scenes. Table 2 shows the abstract classes and traits which represents scenes except for above-mentioned three classes. We abbreviates class and trait names in “Name” and the following by removing the Scene word (e.g. Player indicates Player Scene). The Player, Vein and Main abstract classes are core classes for constructing game flow, which have only a responsibility of processing under game rules without rendering a UI. These classes have responsibilities which enable users to choose the number of players and player names, to select the initial veins and to play the game manipulating players, respectively.