Dungeon Sprint
Dungeon Sprint is a fast-paced Crawl variant coded by Chapayev. It begins by asking you to select your species, background, and which Dungeon Sprint map you'd like to attempt. Each map is a unique single floor for you to complete, but be aware that these are designed to be incredibly hard. The floorplan, monsters, and locations of items and shops are fixed, while the exact items and shops you find are random.
Over the course of a single floor you will find yourself jumping from fighting goblins and rats to high level uniques, including some bosses only found in Dungeon Sprint. In order to give you half a chance at being ready for them, Sprint features accelerated character growth; you gain XP toward levels and skills at 27× normal speed, and piety at 9× normal.
You can play Dungeon Sprint on the server crawl.develz.org (telnet in, port 345), and the source code is also available online in case you want to look at it or change it yourself. Players can easily make a new level for Sprint to take place on by editing the file source/dat/des/variable/entry.des in the Sprint source code, the "dungeon-sprint" branch on git://git.develz.org/crawl-ref.git. Making new levels this way is actually pretty straightforward: Crawl's .des files aren't hard to read and change even for a non-programmer, and there's a how-to guide here.
Trivia
Dungeon Sprint was inspired by the Tomb of Horrors, a Dungeons & Dragons module from the 1970's notorious for being unfairly deadly.
See Also
Zot Defense - Another Crawl variant coded by Chapayev.
Sprint guide - Tips and tricks for beating Sprint.
