Such a representation has been widely used in many top-down perspective strategy games. The advantage is that it is easy to generate automatically [8]. The limitation is that such a representation often requires a large number of cells to adequately represent the game world. Thus, regular grid was soon overwhelmed by the sheer exponential growth in the complexity of the game world such as a complex 3D world. To find a path between any two cells on a regular grid, search algorithms like A* algorithm can be adopted on it and each cell on a regular grid is a node on a weighted graph.