We propose EDGE (An Easy Design Tool of Game Event for Rapid Game Development), with it game designers can make game events and effects without detailed programming skill. In the typical game design phase, the programming of game events is time consuming, non-productive, and burden to programmers; moreover, it is very difficult task for non-programmers. In this paper, we propose EDGE based game design process which clearly guarantees independence of game planning/design phase from the game programming phase. In the game design phase, game designer make events/effects without programming details. After verification of design process by EDGE preview, we can proceed to the game implementation phase, where we can use EDGE generated game source codes. We design and implement EDGE on OpenGL platform, applied EDGE on the development of two major genres of game contents, and the experimental results show that we can increase the productivity and the design maintenance.