Core idea – Beginning of the game concept. Just a few paragraphs describing the game and what it is, a quick overview of the story, the universe and the type of characters. Elaboration on the key elements with perspective of the overall game and what the player will be doing and the flow.
Background concepts – The universe & environment in which the game will play to set the connection between the player and the game concept.
Symbols concept – The flow and universe gives input towards the characters of the game that will be telling the story to the player during the game play
Game Design Document – Documenting and placing all the modules together give the GDD a guide book for the stakeholders all through the game lifecycle.