[aleph_minus_one]

Relevant cultural context from Germany:

In Germany, there exists a popular children's game named "Das verrückte Labyrinth" (in English it's simply named "Labyrinth": https://en.wikipedia.org/wiki/Labyrinth_(board_game) ).

When you get a corner-shaped card (in German: "Eckkarte")

> https://boardgamegeek.com/image/155268/labyrinth

from the turn of the previous player, your intended move will typically be more complicated to visualize (at least for children) - this is what this game is about - so children tended to name a "Eckkarte" an "Ätschkarte".

[adornKey]

Maybe that game exists, but it's an old word and you can find references for it that are hundreds of years old. Its meaning fits to the browser. Your statement that it's just some kind of reference to some special game is not correct.