Towards a Video Game Description Language

This chapter is a direct follow-up to the chapter on General Video Game Playing (GVGP). As that group recognised the need to create a Video Game Description Language (VGDL), we formed a group to address that challenge and the results of that group is the current chapter. Unlike the VGDL envisioned in the previous chapter, the language envisioned here is not meant to be supplied to the game-playing agent for automatic reasoning; instead we argue that the agent should learn this from interaction with the system. The main purpose of the language proposed here is to be able to specify complete video games, so that they could be compiled with a special VGDL compiler. Implementing such a compiler could provide numerous opportunities; users could modify existing games very quickly, or have a library of existing implementations defined within the language (e.g. an Asteroids ship or a Mario avatar) that have pre-existing, parameterised behaviours that can be customised for the users specific purposes. Provided the language is fit for purpose, automatic game creation could be explored further through experimentation with machine learning algorithms, furthering research in game creation and design. In order for both of these perceived functions to be realised and to ensure it is suitable for a large user base we recognise that the language carries several key requirements. Not only must it be human-readable, but retain the capability to be both expressive and extensible whilst equally simple as it is general. In our preliminary discussions, we sought to define the key requirements and challenges in constructing a new VGDL that will become part of the GVGP process. From this we have proposed an initial design to the semantics of the language and the components required to define a given game. Furthermore, we applied this approach to represent classic games such as Space Invaders, Lunar Lander and Frogger in an attempt to identify potential problems that may come to light. Work is ongoing to realise the potential of the VGDL for the purposes of Procedural Content Generation, Automatic Game Design and Transfer Learning.