design documents
It’s naive to think a game can be designed up front, but you still need to communicate your vision with various team members.
That said, people probably aren’t going to read long text documents. Maybe visually focused, one page documents are more reasonable? How about dynamic documents, like Wikis and Trello boards (as described in Game Design Frameworks-Oshea)
Chapter 4 of Game Design Research-Lankoski has good discussion of how design documents should be used.
