In the games industry, the game design document is the one living document where all the information regarding the game, gameplay, characters, win/lose conditions, etc. is held. In our work, we adapted this document for gamification use. When you think about a gamification design document (GDD), it serves as a reference document for everything to do with your design. You would give it to developers and platforms, to help you create the intended solution. All game mechanics, their associated measures, storyline, characters etc are described here. When you iterate the design, it should also be documented here for future reference and ideally with reasons why you adapted it.
In gamification our objective is often business related, so the first heading in the design document is project objectives. Then when there is a theme and overarching storyline that is the second heading. We don’t include the user profile in the GDD but do link to it so we can refer to it if needed. Then we go into the detail of the gameplay and game mechanics. For each of these, we indicate how levels are achieved, how many points need to be accumulated to achieve a new level, what the triggers are for earning points and what messaging goes with this. It is highly detailed.
You would want anyone picking up your work to be able to continue from where you left off and for a developer to be able to build the game from it. In terms of format, it often takes the shape of a Word or Excel sheet with lots of headings or tabs, for quick reference later. For a client, it may be overwhelming to see this. We tend to explain the high-level decision points in a more visual way and provide the detailed GDD as an appendix.
What do you use as your working design documentation?