Magic: The Gathering's Coldsnap set, released in 2006, is being reassessed 20 years on as a design experiment that was more influential than its lukewarm reception suggested. Marketed as the "lost" third expansion of the Ice Age block, Coldsnap was actually built from scratch by a team given just six weeks to recreate the feel of Magic's early, slower-paced era while still fitting into the game's more modern design sensibilities. Though its Limited format drew criticism and its retro mechanics sat awkwardly within Standard, the set's development left a lasting mark on the game in unexpected ways.

The design team blended old-school, grindy cards such as Balduvian Frostwaker and Martyr of Sands with more modern, synergy-driven designs like Haakon, Stromgald Scourge and Zur the Enchanter, creating a set caught between two design philosophies. Its most celebrated innovation, a mechanic called "Superfast" that prevented players from responding to a spell, was removed from Coldsnap before release and handed to another team, who renamed it Split Second and used it to define the following Time Spiral expansion, cementing Coldsnap's legacy as a set whose greatest impact was felt elsewhere.