Speedmapping is a Doom mapping tradition dating back to at least 2001. It was inspired by a very similar Quake exercise of the same name. Simply put, a moderator puts forth a theme for the inspiration of participants, who then attempt to make a map related to that theme. These mappers have a previously arranged amount of time to accomplish this; in most cases this limit is 100 minutes. Sessions are usually coordinated and conducted in IRC channels.
Doomworld held 17 official speedmapping sessions up to autumn 2001. Throughout 2002, sessions were held by Nick Baker (NiGHTMARE) before the tradition moved hands again to Owen Lloyd (Sarge Baldy), who has operated sessions since January 2003. Doom speedmapping sessions have also been held by Tom White (Hyena) and Mike Watson (Cyb). Dan Woodward (Danarchy) has also held a speedmapping session for Heretic.
Speedmapping is also sometimes personally enforced in order to increase mapping efficiency. This technique was notably utilized by Erik Alm, who established time limits for many of the maps of his megawad Scythe, and similarly, Josh Sealy (Joshy) and Darkwave0000 speedmapped many of the maps for their 2010 megawad Speed of Doom.