Editing 4X (section)

===Research and technology===
{{Annotated image| float=right|width=187| height=127|image-width=900|image=Freeciv-2.1.8 technology tree.png|caption=One part of ''[[Freeciv]]''{{'s}} technology tree. Note the complex dependencies between technologies.|annotations=
}}
4X games typically feature a [[technology tree]], which represents a series of advancements that players can unlock to gain new units, buildings, and other capabilities. Technology trees in 4X games are typically larger than in other strategy games, featuring a larger selection of different choices.<ref name="SOSEdistinct" /><ref name="JoystiqSoaSEDesignerInterview"><!--
-->{{cite web |url=http://www.joystiq.com/2008/02/01/joystiq-interview-ironclad-talks-4x-strategy-with-sins-of-a-sol/ |title=Joystiq interview: Ironclad talks 4X strategy with Sins of a Solar Empire |first=Jason |last=Dobson |date=2008-02-01 |publisher=Joystiq |access-date=2008-06-23 |archive-url=https://web.archive.org/web/20080706054054/http://www.joystiq.com/2008/02/01/joystiq-interview-ironclad-talks-4x-strategy-with-sins-of-a-sol/ |archive-date=6 July 2008 |url-status=live }}<!--
--></ref> Empires must generate research resources and invest them in new technology.<ref name="Rollings"><!--
-->{{cite book |first1=Andrew |last1=Rollings |first2=Ernest |last2=Adams |title=Andrew Rollings and Ernest Adams on Game Design |publisher=New Riders Publishing |year=2003 |pages=321–345 |url=http://my.safaribooksonline.com/1592730019/ch10 |isbn=1-59273-001-9 |access-date=2011-02-03 |archive-date=2010-09-17 |archive-url=https://web.archive.org/web/20100917153838/http://my.safaribooksonline.com/1592730019/ch10 |url-status=live }}<!--
--></ref> In 4X games, the main prerequisite for researching an advanced technology is knowledge of earlier technology.<ref name="MobyGames4xDef"><!--
-->{{cite web
 |url=http://www.mobygames.com/game-group/4x-games
 |title=Moby Games' 4x games Group Description
 |publisher=[[MobyGames]]
 |access-date=2008-06-23
 |archive-url=https://web.archive.org/web/20080618074603/http://www.mobygames.com/game-group/4x-games
 |archive-date=18 June 2008
 |url-status=dead
}}<!--
--></ref> This is in contrast to non-4X real-time strategy games, where technological progress is achieved by building structures that grant access to more advanced structures and units.<ref name="dunehistory" />

Research is important in 4X games because technological progress is an engine for conquest.<ref name="earlygameconventions" /> Battles are often won by superior military technology or greater numbers, with battle tactics playing a smaller part.<ref name="Rausch2003a" /><ref name="Butts2006" /> In contrast, military upgrades in non-4X games are sometimes small enough that technologically basic units remain important throughout the game.<ref name="Non4XBasicUnitsRemainImportant"><!--
-->{{cite web
 |url=http://uk.gamespot.com/pc/strategy/starcraft/review.html
 |date=1998-04-15
 |website=GameSpot
 |first=Ron
 |last=Dulin
 |title=StarCraft for PC Review
 |access-date=2014-05-05
 |archive-url=https://archive.today/20121206040615/http%3A%2F%2Fuk.gamespot.com%2Fstarcraft%2Freviews%2Fstarcraft-review-2533189%2F
 |archive-date=2012-12-06
 |url-status=dead
}}<!--
--></ref>