Existing research shows that emotions affect the decision making of the agent and make it appear more human-like. In game industry, emotions of players and non-players characters have not been paid enough attention. This paper presents the development of an Emotion Module in StateCraft, a software version of the social strategy board game Diplomacy, with aims to add emotion to agents in order to make the agent more believable and fun to play with. Based on the OCC-model we conducted interviews with players in order to identify what emotions are experienced in the game. These emotions are then mapped onto the OCC-model and implemented in the agent. We conducted simulations as well as player test to study how the emotions affect the agent performance and player experience.