Sometimes, Magic: The Gathering cards are quite direct in how they interact with other cards. Quarum Trench Gnomes, a card from Legends is one such card.
An interesting card with somewhat quirky art (thanks, Dan Frazier), Quarum Trench Gnomes adversely affects lands. Plains, to be specific, though not in red's usual method of land destruction. Rather, it nerfs them.
How? Why, by making them tap for colorless, of course. Specifically, it replaces a Plains' "Tap for W" to "Tap for 1." And, for good measure, the card specifies that you must use a counter on the affected land to signify the change.
As a result, white-centric players (and, well, anyone who relies on Plains in their deck) were suddenly on notice because of anyone playing the gnome card. While it didn't mess things up as much as a land-specific sweeping destruction spell such as Flashfires, it could lead to some annoyances for the remainder of the game.
At the time, a number of players were up in arms about the card. After all, it was mid-90s and Magic was still figuring a lot out about itself. Quarum Trench Gnomes was the first gnome ever in Magic: The Gathering and it would remain the only one until the release of Homelands in 1995 and the card Clockwork Gnomes.
Clockwork Gnomes was, to put it lightly, quite different than Magic's gnome progenitor. Not only was it an artifact creature (as opposed to Quarum being a red card), it didn't even care about lands at all.
In fact, gnomes in Magic would be drastically different from there on out with each gnome printed thereafter being an artifact creature all the way until 2021's Dungeons & Dragons: Adventures in the Forgotten Realm, which saw the reintroduction of colored, non-artifact gnomes into the game.
Quarum Trench Gnomes will remain forever a Legends-only release, however, thanks to its inclusion on Magic: The Gathering's Reserve List, meaning that it will never see a reprint.
If you want to pick one up for fun, though, they're not all that expensive, listing at less than $20 for a lightly played one.