Editing Doom (1993 video game) (section)

===Clones===
{{See also|First-person shooter}}
[[File:Doom clone vs first person shooter.png|thumb|By 1998, the phrase "[[first-person shooter]]" had firmly superseded "''Doom'' clone".|alt=Double-line graph. X-axis is years from 1993 to 2002. Y-axis shows usenet post counts ranging from 0 to 1200 per month. Red line ("doom+clone" or "doom+clones") peaks at about 400 in 1996, and tails off to zero again by 2002. Blue line ("first+person+shooter" or "first+person+shooters") grows mostly monotonically to about 1120 by 2002, with an intermediate peak of about 850 in 2000. The two lines cross in late 1997. Both lines are close to zero before late 1993, when "Doom released" is noted with a visual marker.]]
The success of ''Doom'' led to dozens of new first-person shooter games.<ref name="DoomChildren"/> In 1998, ''PC Gamer'' declared it "probably the most imitated game of all time".<ref name="pcgtop50"/> These games were often referred to as "''Doom'' [[clone (computing)|clones]]", with "first-person shooter" only overtaking it as the name of the genre after a few years.<ref name="DoomClones1"/><ref name="DoomClones2"/><ref name="DoomClones3"/> As the "first-person shooter" genre label had not yet solidified at the time, ''Doom'' was described as a "first person perspective adventure" and "atmospheric 3-D action game".<ref name="GShistoriography"/>

''Doom'' clones ranged from close imitators to more innovative takes on the genre. Id Software licensed the [[Doom engine|''Doom'' engine]] to several other companies, which resulted in several games similar to ''Doom'', including ''[[Heretic (video game)|Heretic]]'' (1994), ''[[Hexen: Beyond Heretic]]'' (1995), and ''[[Strife: Quest for the Sigil]]'' (1996).<ref name="DoomClones2"/> A ''Doom''-based game called ''[[Chex Quest]]'' was released in 1996 by [[Ralston Foods]] as a promotion to increase cereal sales.<ref name="DoomChex"/> Other games were inspired by ''Doom'', if not rumored to be built by [[reverse engineering]] the game's engine, including [[Lucasfilm Games|LucasArts]]'s ''[[Star Wars: Dark Forces]]'' (1995).<ref name="DoomClones2"/><ref name="DarkForces"/> Several other games termed ''Doom'' clones, such as ''[[PowerSlave]]'' (1996) and ''[[Duke Nukem 3D]]'' (1996), used the 1995 [[Build engine]], a 2.5D engine inspired by ''Doom'' created by [[Ken Silverman]] with some consultation with John Carmack.<ref name="DoomClones2"/><ref name="BuildEngine"/>