You probably already knew I am a game designer before you came here. When people hear "game designer" they often get the general picture. Since you do not hire someone because you have a general idea of what he or she is doing, I will try to sharpen your image of myself in this online portfolio.
What is a Game Designer?
Game design is the act of deciding what a game should be.
-- Jesse Schell (author of "The Art of Game Design")
During the development of a game many people have ideas about what they want to create. Even before they are touching a keyboard or pen they have to start making decisions about their creation. Everyone who makes a decision about the game is designing it; every programmer, 2d/3d artist, sound designer, writer and producer. So, when everyone working on a game is doing game design already, where is the point in having a game designer?
As a producer is responsible for the quality, the game designer is responsible for the experience of the player. State of the art games are seldom built by a single person. Large development teams tend to have lots of ideas. Decisions have to be made constantly by people with completely different professions and it is not surprising when some oppose each other. Game designers listen to those ideas and decisions. To completely understand the details they need to have skills of different professions; being i.e. artist and programmer. Because great ideas which do not help to improve the experience may not be a worthwhile investment a game designer filters them.
Different players can have different experiences while playing the same game. How can someone know about other peoples experiences? The most obvious way to learn about peoples experiences is to do playtesting. Therefore, you need to build something first. However, it is hardly possible to playtest everything and decisions have to be made on a daily basis. Unusual ideas or what might have been a big feature may get rejected by playtesters because they did not get the chance to test it completely.
Game designers are often called artists, because they know how to shape experience. They are trained to analyze every game they play in great detail, so they know how a game is build and can break down what they experienced.
A good game designer has a lot of training in analyzing games and listening to other people's ideas. Furthermore, he or she has several skills of other professions useful in game development, some of them might even be highly developed. A game designer has to constantly improve his or her skills. Every skill is a valuable contribution.