Mark Fennell | Technical Director | Game Developer

HTML5, iOS, Android, AS3, UX, Process

Game Development : The Game Definition Document


The next step after the Mindmap planning process is to create a Game Definition Document (GDD). It’s a blueprint for building a game, covering off the core ideas, mechanics, assets needed etc.

It needs to be an evolving document, but really helps cement the bigger picture and requirements as to whats involved in creating the game. It’s also very useful if you are going to outsource the development or graphics in the game. A subject of a later post.

I use Google Docs to create my GDD’s, they allow collaborative editing if there is more then one person involved, are easily shareable, and support inline commenting for handling feedback.

My GDD is broken down into the following sections.


An overview of the game project, the elevator pitch of the project. If you were to describe the game in 1 or 2 catchy sentences then do it here.

Game Play

An overview of the core game play mechanics in the game.

The game objectives, i.e., why are you doing it, how do you win

What makes this game fun.

What is the story to the game, why are we playing it.

What perspective is the game, 2d, isometric, 3d, etc etc

The Camera is the view into the game world, how does the camera work, does it follow the main character, can you control it ( e.g. with a mouse look around )

What is the game world, the terrain, environment

Items in the game that are obstacles to the play.

What are the controls in the game, mouse, keyboard, thought :D

Who are the characters in the game, the player and NPC’s.

In game pickups and their effects.

In App Purchasing

Micro transactions and how they work in game


An overview of the design of the game. The overall aesthetic and creative direction.

The world, environment, you could detail backgrounds, locations etc, whatever is relevant to the game

Character design details

List any in game effects, dust, particle trails, etc

List of animations required in game, character, ambient etc.

References to similar games, videos or

Game Screens Required
List of pages / sections within the game

InGame Display ( HUD )
In game GUI Items, e.g. Score, Timer, Lives etc

Game Dimensions
Game dimensions


Description of game levels.


Music and sound effects listing


Description of scoring mechanics and achievements


Deployment Targets
Where is the game being deployed, e.g. app store, Facebook, web etc

How is the game to be delivered, app, swf, exe. Single file, multi file….

Technology Requirements

3rd party Library Support
Any 3rd party technologies or libraries that are supported, e.g. Game Center


Any assumptions, e.g. graphics provided etc.  Useful if this document is going to a developer so they know what to expect.


And here’s one that I prepared earlier the GDD for the game so far

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