Definitions for "Game designer"
a person who constructs or co-ordinates the mechanical, parametric and high-level design of a game. If the person also writes dialogue for the game, they can be considered a writer-designer (qv).
an accomplished writer who communicates clearly through the written word, charts, graphs, and sketches to set forth the vision for a game in complete detail so that the programmers and artists will have their work clearly cut out for them
a person who designs games A game is a recreational activity involving one or more players, defined by a) a goal that the players try to reach, and b) some set of rules that determines what the players can do