A file with .mgx extension is a recorded file for Age of Empires II: The Conquerors game that can be replayed within the Age of Empires II program. It contains complete recording of the campaign played by the user. It can be loaded and played back within in the Age of Empires II program. Once replayed, the game shows all the events and scenarios that the user planned for the campaign and played.
The structure definitions of GPX file format are believed to be based on the BinData Ruby Gem declarations that provide a way to read and write structured binary data. This lets the programmer specify the format of the binary data which is then read and write by BinData.
The MGX messaging is based on two type of messages.
GAMESTART - specifies the game start commands and is not validated to date
CHAT - describes the in-game chat messages. Both, players and the game itself (Gaia) can emit in-game messages.
There are several GAMEPLAY Actions that have been retrieved and whose details are available.