This paper introduces the Dialogue Game Description Language (DGDL), a domain specific language for describing dialectical games. Communication is an important topic within agent research and is a fundamental factor in the development of robust and efficient multiagent systems. Similarly, argumentation has been recognised as a key component of an agents ability to make decisions using complex, dynamic, uncertain, and incomplete knowledge. Dialectical games, a type of multi-player argumentative dialogue game, provide a mechanism for communication which incorporates argumentative behaviours. However there are very few tools for working with these games and little agreement over how they should be described, shared, and reused. The DGDL provides a grammar for determining whether a game description is syntactically correct and thus provides a foundation for new tools to support the future development and wider exploitation of dialectical games.