DCSS April Fools' Jokes
Each year on April Fools' Day, Dungeon Crawl Stone Soup's dev team releases a mock update. Although primarily meant as a gag, these DCSS versions are still playable, and many players treat these joke updates as an opportunity for a unique challenge.
On April 1, 2014, a Nostalgia update was applied to DCSS, restoring a wide variety of "classic" Crawl features, such as Zot traps appearing on any floor and hydras having speed 15, as well as the restoration of all obsolete species and backgrounds. In game text was also given more exclamation marks, and your god would make commentary on your performance.
On April 1, 2013, the jester background was (briefly) added to the game. Although only playable for a short time, several players managed to win with it before its removal.
On April 1, 2012, the game was translated to a few "exotic" languages: dwarven, jägerkin, lithp and kraut. The reception of this feature was so positive, that this joke was not completely reverted, and new fake languages were added to the game after that.