The gameplay of Pokmon Emerald, just like Pokemon Ruby and n Sapphire, takes place in an overhead style where players can encounter wild Pokemon by walking into grass or through caves, and surfing on their Pokemon, among otherways.
The gameplay in Emerald is largely the same as in Ruby and Sapphire. Much of the game takes place in an overhead style; players' characters can move in four directions and can talk to other people on the overworld. Players can encounter wild Pokemon by walking into grass, surfing on their Pokemon, walking through caves, and other means. 
