Design Document
Design document is probably the holiest of holy things about making games. It is the source of all truth, the reference of all desicions and so on.
Our design document tried at first to define anything about the game in the tiniest detial. It failed. Thus the second ( or was it third... ) aims to set the framework of making design decisions without making final statement about them. It defines features, but does not enforce their concrete implementations. The goal is to be flexible enough to implement only the most relevant features as the project progresses and remove those which are deemed too expensive to implement.
The latest version of the DD, straight from the code repository, can be accessed here: