The main purposes of a game definition language are: to simplify the task of implementing the game, compared to coding it directly in a programming language; to define a standard representation, ensuring that everybody uses the exact same definition of the game, thereby enabling scientific methods of operation such as repeatability of experiments and clear communication of results; and finally to serve as a long-term repository, releasing the game from dependence on computer hardware and operating systems. The major problems that the human writer of the game definition faces are: how to turn the game rules into statements in the formalism, and how to ensure that the game definition as a whole is complete and correct. This seems to suggest that a helpful design of a game definition language is one where the game definition closely follows a description of the game written for human consumption; where standard devices, such as tables and gridded mapboards, can be encoded easily and succinctly; and where the game definition is clear and compact.