FUNDAMENTALS OF GAME DESIGN, SECOND EDITION
. The Game Design Documents
As part of their job, game designers produce a series of documents to tell others about their game design. Exactly what documents they produce and what the documents are for vary from designer to designer and project to project—but they usually follow a common thread.
Beginning game programmers often make the mistake of thinking up a game and then diving in and starting to program it right away. In modern commercial game development, however, this kind of ad hoc approach is disastrous. Different projects require different degrees of formality, but all serious game companies now insist on having some kind of written documentation as design work progresses.
A key part of game design is transmitting the design to other members of the team. In practice, a lot of that communication takes place not through the documents themselves but during team meetings and conversations over lunch. That doesn't mean that there's no point in writing design documents, however. The documents record decisions made and agreed upon orally; they create a paper trail. More important, the process of writing a document turns a vague idea into an explicit plan. Even if no one reads it at all, an idea written down is a decision made, a conclusion reached. If a feature of a game is not described in writing, there's a good chance that it has been overlooked and that someone will have to make it up on the fly—or, worse, that each part of the team will have a different idea of what they intended to do. It's far easier and cheaper to correct a design error before writing any code or creating any artwork. Depending on the size of the game, wise developers allot anywhere from one to six months for pure design work before starting on development, usually in combination with some throwaway prototype for testing gameplay ideas.