"Chekhov's gun is a dramatic principle that states that every element in a story must be necessary, and irrelevant elements should be removed. Elements should not appear to make "false promises" by never coming into play." If you show it to the reader, it should matter. Infinite stories on the other hand thrive on having elements where unnecessary things can become part of the expansion of the story.
. Magic The Gathering is famous for having a game system that changes every time the publisher releases a new set of cards. MtG’s metagame is thus a race to see who can discover new card combinations or strategies given the new options. The players who do so are rewarded with easier wins, especially when going up against players who have not adapted to the new possibilities. This makes MtG a game of two levels: the first game is the game you’re playing when you sit down and shuffle cards to battle an opponent; the second game is the race to acquire, analyse and adapt to new cards quicker than your competition.