Gamification and games
Gamification is a way for a product to recognise what its users do: the badges they earn, the levels they reach, and the kinds of event that count toward them. It is built on a record of events, so past events can be replayed to rebuild what everyone has earned. A product's mode is one of none, gamification or game, and that one setting is the answer to whether the product has a game.
Games is the backend for a product that is a game. The hub keeps the game's artifacts, sessions, events, players and holdings in typed form, and its stats, definitions, effects, mappings, instances and key values in a generic form. The hub hosts the game's backend, not its engine. A product has at most one game, created for it when its mode becomes game. Once a game artifact is published it cannot change.