Metagame
Etymology
Built from Greek "meta" (beyond, about) plus "game," the term spread through competitive card games, chess, and video games for the strategic context surrounding formal play — "the meta." A popular backronym claims it stands for "most effective tactic available," but that is a later folk invention. It generalizes to any field where the best move depends on what rivals are doing.
noun · /MET-uh-gaym/
The evolving layer of strategy shaped by which tactics everyone else is currently using.
What it names
The game beyond the game — the shifting environment of prevailing strategies you must play against, not just the fixed rules.
Example
In hiring, résumé keywords are a metagame — everyone optimizes for the filter, so the filter stops meaning much.
Related idea
The metagame is about adapting to prevailing strategies, while Goodhart’s law explains why optimizing for the very measure that defines them corrupts it.