Land cards in Magic: The Gathering are usually one of the more straightforward types of cards. You need mana, you tap it - boom - you can now bring into play a creature or artifact or whatever you're able to afford. Every once in a while, though, the game tries to sneak a kook in.
There was, of course, the never ending saga of Barry's land and the rumored sixth purple land. Others are so bad that they get the reputation as the worst land card. And then there is the story of what may be the oddest land type ever made: locus.
To tell locus' story, we need to go back to 2003 - a time when the Montréal Expos still existed, when the War in Iraq was mission accomplished, and when R. Kelly was still an upstanding citizen.
For the newest set at the time, Mirrodin, developers wanted to have a special land to fit in with the theming. As it was set on an artificial world, a special land associated with beings "watching" over the area was created - locus.
But a problem soon arose.
As each locus land granted a colorless mana bonus with every additional locus, players could rack up land fast.
This was, well, breaking the game somewhat.
In the end, only one locus land, Cloudpost, made it in, and even then it was limited as it could still rack up usable land pretty fast. Cloudpost still wound up pretty powerful, so it was quickly phased out by the next year and became the only card to be a locus land type.
That is, the only one until 2010.
Scars of Mirrodin came out that year, and with the return of Mirrodin came the return of locus lands. Specifically Glimmerpost, which, instead of quickly accumulating land, you could quickly accumulate life due to it kind of adding another for each locus already being played.
Cloudpost and Glimmerpost, along with cards that allowed to make copies of them, like Vesuva from Time Spiral, turned out to be a very formidable foe in competitive circles.
Following Glimmerpost, no more locus cards have been printed to date because of how game breaking they can be. Even more, Cloudpost was eventually banned in Modern (though, the cards are seen in Legacy thanks to the various Eight-Post decks).
That's how bad it used to be.
The combination of them, as well as your opponent having them, led to some really unusual tournament matches that acted really more as arms races.
Today, thanks to the ban and no more locus' being printed (at least, none we're aware of), the impact of them has faded away. But, that doesn't mean a third locus land may come around.
And if it does, who knows what stats that one will pump up.