In virtually any tabletop game, a lot of groups have the Veteran Player, that guy who knows the game so well that he over-thinks things, not in a way a character would, but from past experience. Not maliciously, but instinctively. And God help you if you have two of them.
New players check doors and chests for traps. Veterans check the ceilings. And Genre Savvy veterans let somebody else check the ceilings.
On the other hand, if a veteran player expected a chest to be a Mimic and told the new players to open it, yet it turned out to contain precious treasure, then their savviness backfired miserably and turned them into Wrong Genre Savvy.
Changeling: The Lost has the Talecrafting rules in the sourcebook Swords at Dawn: characters can purposely force Tropes to occur at will because they realize their own lives work by the rules of stories. The book actually suggests TV Tropes as a good place to find examples of patterns to use!
Metagaming is actually an option for player characters in Grimm. The Gaming trait covers knowledge of such things as fairy tales, fantasy novels and films, fantasy card and board games, narrative video games, and the game Traps and Trolls. Since it covers not only knowledge of fairy tales, but things that are either directly or indirectly inspired by them, you can use this trait to cast or identify spells, recognize fairy tale settings or characters, and determine the weakness of fairy tale characters.