http://blog.ihobo.com/2017/07/metagame-vs-structure.html

The structure of a game is the framework of the design that compels players to keep playing over the long term. There are numerous different game structures, including narrative structures (linear, branching, threaded), geographical (sequential, hub and level, open world), and in terms of character advancement (class and level, advantages/perks etc.). Conversely, the metagame is the social consequence of releasing a game into a community of players, an ever-changing set of tactical and strategic considerations that have to be taken into account if players are going to remain engaged with the games’ community.