In the Eppx system, all the action takes place within a campaign. A campaign has a game master (usually, the person who creates and runs the campaign) as well as one or more other players. Players make their characters within the campaign, and all things that happen to a character happen within a campaign. You might think of a campaign as a single game that might last one day or a year.
The campaign takes place within a world, which is managed by the game master. A new world is created for each player when they sign up for a new account and, by default, any new campaigns are created within that world. New worlds can be created if the player wants to create campaigns with different styles. For instance, a player might have a fantasy world where they run several fantasy campaigns, and another sci-fi world where they run sci-fi campaigns.
Modules are what makes a world. A module can define species, anatomy, stats, character attributes, skills, items, areas, encounters and rules for all of them. More than one module can be activated for a world – so a player can create a world that has both sword-and-sorcery as well as science fiction elements by enabling the appropriate modules.
Currently, there’s only a single default fantasy module that defines everything. In the future, this might be narrowed down with multiple base modules. For instance, it might be a good idea to have a module that defines “human” that provides the basics that other modules can build off of.
In coming releases, you’ll be able to craft your own module and share it with others, allowing you to customize anything in a game. Want to make a new unusual species? A new skill that characters can learn? A dungeon for characters to crawl through? Change a game mechanic? Make a module!