This thesis talks about developing an application for an Arabic card game called „Trex” or „Trix” on Android platform. This game consists of four players, each player has five games to play or as they are called “five kingdoms”. Each kingdom has its own rules and its own number of points that a player gains or losses depending on the different situations he/she faces. For this application, I created the three computer players and taught them how to think, how to choose the best kingdom among the five kingdoms depending on their set of cards to increase their chances of winning, as well as teaching them what card to choose while playing a kingdom. This application has a nice and friendly graphical user interface to ease the interaction between the user (human player) and the other three players. For this purpose , I used a well-known and a simple software called Eclipse that uses Java as its programming language, adding to it the Android software development kit (SDK) that includes a comprehensive set of development tools, including a debugger, software libraries, etc…. and of course a virtual device is needed too for testing where I used for this project : GenyMotion due to its simplicity and clarity.