In 2006, there was a Magic: The Gathering expansion that effectively replaced another in a block...that was 15 years in the making.
From the mid 1990s though to the mid-10s, Magic had the block system - a lumping of two to three expansions put together to create a story and to create comprehensive play. And all of them led into each other into the continuing Magic story and a clear plane of play to easily phase in and phase out things like mechanics. But in 2006, the only ever alteration in the block system came when Coldsnap "finished" a block from a decade before.
In the mid 90s, the first block, the Ice Age block, began. The lead in from Ice Age to Alliances to Homelands was seen as innovative and influenced sets and expansions for years to come. But the problem was that Homelands didn't really wrap up the block. In fact, is was developed as a separate expansion and was only included in the block sort of last minute. There were snow lands and some shared mechanics with the others in the block, but otherwise it was only sort of seen as the final expansion in the block.
However, a little over ten years later, Magic had an open slot, and in six weeks, developed Coldsnap to finally finish off the block. Homeland officially became designated as a standalone. However, as it had been ten years since Alliances and Magic changed a lot since then, they decided to go with a more "retro" design. Pitch cards, snow lands, allied colors - Coldsnap was a an anomoly.
All the unique types in there made Coldsnap unpopular to pick in chaos drafts and made it a hard expansion to integrate in decks at the time, thanks to Ice Age and Alliance expansion packs to mix in being hard to get. But what it did wind up doing is finally completing the Ice Age block. Throughout all of Magic history, Coldsnap remains the only expansion to ever replace another in a block, with Homelands being the only one being re-designated as a standalone.
And it will probably be the only one. Unless block systems are brought back and Magic feels like there is a need to swap one expansion out for another. But, pretty much every other block out there has been so crafted around expansions and stories, that you would be hard pressed to find another to do that with.
Learn more about Coldsnap in our MTG History video:
