Editing Doom (1993 video game) (section)

===Sequel and franchise===
{{main|Doom (franchise)|l1=''Doom'' (franchise)}}
After completing ''Doom'', id Software began working on a sequel using the same engine, ''Doom II'', which was released to retail on October 10, 1994, ten months after the first game. GT Interactive had approached id before the release of ''Doom'' with plans to release a retail version of ''Doom'' and ''Doom II''. Id chose to create the sequel as a set of episodes rather than a new game, allowing John Carmack and the other programmers to begin work on id's next game, ''[[Quake (video game)|Quake]]''.<ref name="MOD180182"/> ''Doom II'' was the United States' highest-selling software product of 1994 and sold more than {{nowrap|1.2 million}} copies within a year.<ref name="Doom2sales1"/><ref name="Doom2sales2"/>

''Doom II'' was followed by an expansion pack from id, ''Master Levels for Doom II'' (1995), consisting of 21 commissioned levels and over 3000 user-created levels for ''Doom'' and ''Doom II''.<ref name="DoomMaster"/> Two sets of ''Doom II'' levels by different amateur map-making teams were released together by id as the standalone game ''[[Final Doom]]'' (1996).<ref name="FinalDoom1"/><ref name="FinalDoom2"/> ''Doom'' and ''Doom II'' were both included, along with previous id games, in the ''id Anthology'' compilation (1996).<ref name="Compilation1"/> The [[Doom (franchise)|''Doom'' franchise]] has continued since the 1990s in several iterations and forms. The video game series includes ''[[Doom 3]]'' (2004), ''[[Doom (2016 video game)|Doom]]'' (2016), and ''[[Doom Eternal]]'' (2020), along with other spin-off video games.<ref name="IGNDoom3Versions"/><ref name="IGNDoom4"/><ref name="DOOMEternal-release"/><ref name="DOOMspinoffs"/> It additionally includes [[Doom (novel series)|multiple novels]], a comic book, board games, and two films: ''[[Doom (film)|Doom]]'' (2005) and ''[[Doom: Annihilation]]'' (2019).<ref name="Novels"/><ref name="Boardgame"/><ref name="Films"/>