Editing Civilization IV (section)

===Customization===
''Civilization IV'' is much more open to modification than its predecessors were. Game data and rules are stored in [[XML]] files, and a [[Software Development Kit]] was released in April 2006 to allow customization of [[game AI]]. The map editor supports [[Python (programming language)|Python]].<ref name="ignfaq"/><ref name="gamespy">{{cite web |url=http://pc.gamespy.com/pc/civilization-iv/662218p1.html |title=GameSpy: Civilization IV |last=Kosak |first=Dave 'Fargo' |date=27 October 2005 |publisher=[[GameSpy]] |pages=1–3 |id=662218 |archive-url=https://web.archive.org/web/20131206061753/http://pc.gamespy.com/pc/civilization-iv/662218p1.html |archive-date=6 December 2013 |url-status=dead |access-date=24 October 2009}}</ref>

The World Builder allows a player to either design a map from scratch or edit a preloaded template map as a starting point for a new game. The player can modify the map by placing and modifying any number of rivers, landmasses, mountains, resources, units, and cities, as well as their attributes such as Culture generation. The World Builder for ''Civilization IV'' is in-game, in contrast to previous ''Civilization'' games where the Map Editor was an external application.<ref name="firaxisdevblog">{{cite web |url=http://www.2kgames.com/civ4/blog_03.htm |title=Modding Sid Meier's Civilization IV |last=Caudill |first=Barry |date=20 September 2005 |website=[[2K Games]] |publisher=[[Take-Two Interactive]] |access-date=24 October 2009 |url-status=dead |archive-url=https://web.archive.org/web/20101202164144/http://www.2kgames.com/civ4/blog_03.htm |archive-date=2 December 2010 }}</ref>

More game attributes are stored in XML files, which can be edited with an external text editor or application. On September 20, 2005, [[Firaxis Games]] [[senior producer]] Barry Caudill stated that "[e]diting these files will allow players to tweak simple game rules and change or add content. For instance, they can add new unit or building types, change the cost of wonders, or add new civilizations. Players can also change the sounds played at certain times or edit the play list for your soundtrack."<ref name="firaxisdevblog"/>

The ''Civilization IV'' [[software development kit]] was released on April 13, 2006, to coincide with the release of the v1.61 patch. The kit allows players to view, modify, or even completely re-write the game's [[Dynamic-link library|DLL]] [[source code]], enabling the modification of the game's [[AI]] and other integral parts of the game that were previously not accessible.<ref name="civdownload">{{cite web |url=http://www.2kgames.com/civ4/downloads.htm |title=Civilization IV Downloads |website=[[2K Games]] |publisher=[[Take-Two Interactive]] |access-date=27 October 2008 |url-status=live |archive-url=https://web.archive.org/web/20080513225741/http://www.2kgames.com/civ4/downloads.htm |archive-date=13 May 2008 }}</ref>