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 no greater than a few hours. Originally, sessions were usually coordinated and conducted in IRC channels, but they shifted to forums, such as Doomworld, and Discord servers.
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. Further series that lasted beyond a single installment include the Eagle Speedmapping Sessions and Pigeon Speedmapping Sessions.
In 2007, the long-running 32in24 series began, creating a megawad's worth of multiplayer maps in 24 hours, with some authors using the time to make multiple maps. Some entries in the series went on to win Cacowards. In the 2010s, the Abyssal Speedmapping Sessions became the most prominent regular speedmapping event, gathering up to 20 maps per session at its peak.
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.