Sid Meier's Civilization IV (called Civilization IV or Civ4 for short) is a turn-based strategy computer game released in 2005 and developed by lead designer Soren Johnson under the direction of Sid Meier and Meier's studio Firaxis Games. Until 2010 it would be the latest installment of the acclaimed Civilization series. Civilization IV was released between October 25 and November 4, 2005 in North America, Europe, and Australia.
Civilization IV is a turn-based game in which the player builds an empire from scratch. All standard full-length games begin in the Ancient Era (4000 BC) with a single Settler to build one's first city and a Scout or a Warrior, depending on a civ's starting technologies. From there, the player expands the empire while contending with rivals, utilizing the terrain, and developing technology.
The player has several obstacles to face, modeled on political or economic problems faced by real-world nations. Apart from this they also have to handle their diplomatic relations with rivals and their continuing quest for exploration and new resources. Other important tasks include the planning of where to build new cities and progress in science which reveals access to new technologies. A player has the choice of playing the part of one of a number of historical figures such as Elizabeth I (England) to Mao Zedong (China).
The scope of the game ranges from around 4000 BC to 2050 AD. Civilizations gradually advance in technology based on their own production of "research" and sometimes the work of Great People. Technologies range from writing and pottery through paper and gunpowder to genetic engineering and nuclear fusion. All technologies reveal new possibilities for a civilization and enable the chance to trade with other civilizations for military aid, gold, resources or other technologies. The concept of technological growth is based on a technology tree.
Another important concept in the game, not present in the earliest games in the series, is the growth of culture, which expands one's cultural borders and can also cause one's culture to infiltrate into another civilization's, sometimes causing a city to rebel against its current owner. Culture is increased through the creation of World Wonders (which may have bonus effects), constructing certain buildings in cities, and the spreading of a number of religions (see below).
The game can be won through conquest (conquering all other civilizations), domination (controlling a percentage of the world's land and population), the space race (being the first to construct a spaceship capable of colonizing Alpha Centauri), culture (increasing the cultural ratings of three different cities to "legendary" levels) and diplomacy (through votes in the United Nations). Finally, if the game's clock runs out (by default in the year 2050 AD), the nation with the highest composite score is declared the winner.
Diplomacy in Civilization IV generally involves the trading of goods and forming strong alliances.
Different trade options require different advancements to unlock, and some things may only be traded for certain other things (e.g., per turns deals must be compensated by another per turn deal). Players may trade technologies, resources (including luxuries such as wine), maps (to reveal information about the rest of the world) and gold.
Advanced diplomacy options include the creation of trade embargoes, the promising of military aid, and the adoption of particular civics and/or a religion.
The reasoning behind diplomacy is more transparent when compared to Civ3: the Diplomacy window now not only displays the other leaders' attitudes (gracious, friendly, pleased, cautious, annoyed, furious), but why they feel that way (e.g., "-2: You refused to stop trading with our worst enemies!"). When a leader is friendly or gracious towards one's civilization, they are more likely to accept deals without unfair bargaining.
Another new feature is the new abilities of the United Nations. The United Nations wonder allows passing global resolutions (e.g., the Nuclear Non-Proliferation Treaty) in addition to granting access to diplomatic victory. Unlike real-world resolutions, Civilization IV's resolutions are binding, except that in Beyond the Sword you have the option of defying resolutions.
Units no longer have separate attack and defense values. Instead, they have a base strength that is increased or decreased depending on the situation. The unit's strength also affects how much damage it can do. Prior to the 1.52 patch, the unit's damage was calculated using its current strength (which also acts as life/hit points and changes accordingly). After the patch, the damage is calculated from the base strength - this means that badly damaged modern units can still easily win battles against obsolete units. Instead of generic increases in rank, individual units gain specific types of combat experience, such as bonuses against specific types of enemies or abilities like faster movement in forests. In total, there are 41 different types of combat promotions. It is also now possible for players to examine "combat odds" before attacking, giving the player a good sense as to whether a given attack will succeed or not, factoring in all the various bonuses and penalties associated with terrain, unit capabilities, and so forth.
The 1.61 patch brought further changes, and now damaged units attack or defend with the average of their current and full strengths.
Production and trade
The game features 32 types of resources, all of which are tradable and require an improvement (such as a mine or an oil well) to be utilized. Some resources are required for certain units, buildings, or wonders (iron, copper); some may double the production speed of a certain wonder (marble, stone); and some act as luxuries like in Civ III, providing either happiness or health to all cities connected to them (fur, dye, incense). There are also three types of culture goods provided by World Wonders, rather than resources, that can be traded: Hit Singles, Hit Movies and Hit Musicals. To trade goods or to send them to other cities within one's border, they must have some form of connection between the goods and the city. In the later game, this connection can be through ocean tiles, but in the early game, it is limited to roads and rivers. Cities on the same river are automatically connected for trading purposes, while cities on the same coastline are connected for trading purposes once the Sailing technology is researched.
Production (also - as it was in Colonization - known as "Hammers," the icon that represents it) is sometimes used as a resource-term on Civilization. Each tile provides a city with a certain amount of "Hammers" which collect up in the city to produce buildings and units. Unlike in Civilization III, the player is no longer able to transfer all production from one project to another, but all production on a certain project will remain. For example, if the player is building a temple but decides to switch to a harbor, production on the harbor will have to start from scratch. However, the temple stays in the building queue and retains its previous progress, aside from some decay over time. As an ancillary rule, if one culture is building a World Wonder but another empire completes it first, the losing culture is compensated with gold proportional to the amount of Production points lost.
The concept of separate religions is new to Civilization IV. In previous games, players could build temples and cathedrals, but the religion was just a generic feature of happiness and culture. There are now seven distinct religions in the game: Buddhism, Christianity, Confucianism, Hinduism, Islam, Judaism, and Taoism. There are no bonuses or traits specific to any religion, except that each religion is tied to a specific technological advance, and the four later religions (Christianity, Confucianism, Islam, and Taoism) begin with a free Missionary unit for reasons of game balance. Also, the respective cathedrals of each religion have different resources that aid in their construction, although are not necessary. If a player is the first to discover a certain religion on the tech tree, they can "found" the new religion; a city with no religion or the newest city in that civilization's empire becomes that religion's holy city. The player can then build Monasteries and train Missionaries to spread their religion(s) to other cities, both foreign and domestic. (Colonization also has missionaries, spreading their version of Christianity.)
Religion factors into a number of existing game mechanics. Civs that share a common state religion will be friendly in their diplomatic dealings; conversely, civs with differing state religions will be hostile to each other. Securing an open-borders agreement, sending in missionaries and then encouraging the other civ to convert is a relatively painless way of encouraging international tranquility. The founding civ of a religion also receives an economic benefit: if that civ expends a Great Prophet at their religion's holy city, they will receive that religion's most sacred building (the Kashi Vishwanath, the Church of the Nativity, etc.), which provides a 1-gold-per-city tithe from every city hosting that religion. Finally, if a civ has 1) a state religion, 2) that religion's holy city and 3) that religion's sacred building, they will receive line-of-sight in every city hosting said religion, providing additional intelligence and a good way to keep an eye on foreign progress. Additionally, if one can gain an early diplomatic victory by building a Apostolic Palace, which also has the same features as a UN building, though nations can only be members if they have at least one city with the same religion as the Apostolic Palace (your state religion).
The new civics model of government also has a strong effect on religion: players can found a state religion, declare religious freedom, or take other actions that have profound impacts on the religious lives of their subjects. If a civilization has no declared religion, they are exempt from all described bonuses and penalties.
Civilizations and leaders
Eight of the eighteen civilizations have two leaders. Each leader offers bonuses based on what conditions were exceptional during the historical reign of that leader, and each leader acts as differently as if they were a separate civilization and have distinct personalities. Several historic figures not used in previous Civ games are AI leaders in Civ4, including: Asoka, Cyrus II, Franklin D. Roosevelt, George Washington, Hatshepsut, Mansa Musa, Kublai Khan, Peter the Great, Qin Shi Huang, Saladin (though Saladin was a hidden leader in Civilization II), and Queen Victoria.
All civilizations have some element of uniqueness and all leaders have certain traits based on their achievements in real life. While these are limited, they have some effect on a player's game plan. All civilizations also have a unique unit which can be military (such as Persian Immortals) or economic (such as Indian Fast Workers). Below is a summary of each civilization's capital and unique features.
As in prior versions of Civilization, there are technologies for the civilizations to discover. There are a total of 85 technologies in the game, up from 80 in Civilization III. Technologies have many uses; they can be used for trade, for the construction of new buildings and wonders, for the founding of new religions, or for the development of new forms of government. To discover modern technologies, it is first necessary to discover the technologies that lead up to it (for example, democracy can only be discovered after the printing press). See List of technologies in Civ4 for complete list. See the full tech tree here.
Technology development is flexible: certain technologies can be discovered in more than just one way. The game has a very useful tech tree, which can be accessed by pressing F6 on the keyboard. The tech tree displays all the techs in the game and their relations with one another. It is possible to select even unavailable techs for research. This will cause all the prerequisite techs to be researched in order. If multiple paths lead to the target tech, the civilization will pick the shortest. The final tech or group of techs, as in previous versions, are called "Future Tech", followed by a number. Instead of simply adding on to the final score, however, as in earlier games, each city receives a happiness and health bonus for each future tech discovered.
In single-player games, the discovery of each tech during the game is accompanied by a famous quotation from history which is voiced by Leonard Nimoy of Star Trek fame. The sources of the quotes range from the Buddha, Charles Darwin, Brillat-Savarin, Steve Wozniak, Henry Ford, the Bible all the way to Lonnie Donegan, and Dan Quayle.
In Civilization IV the leadership skills of players are compared to a subjective list of twenty of the best or worst leaders in history, similar to the list in Civilization I. The score is based on a number of factors, including military growth and success, technological advancement, construction of wonders and economic growth. It is shown at the end of the game.
|9||Charles de Gaulle||9,000-9,499|
|12||Ivan the Terrible||7,500-7,999|
|18||Warren G. Harding||4,000-4,999|
|19||Ethelred the Unready||3,000-3,999|
|20||Dan Quayle||< 3,000|
The released version of the game abandoned Civilization III's graded scale. In Civ3, a spectacular victory on the easiest difficulty would provide the player with only a middling score, and the best titles were only awarded to players attempting the hardest difficulties. The original Civ4, on the other hand, allows the player to obtain any score on any difficulty level. As of the v1.61 patch, the grading system has returned to the curved-by-difficulty scale.
Many aspects of Civilization IV are new to the series (though some appear in spinoffs or Colonization). These include:
- Great People that fall into five categories: artists, merchants, prophets, engineers, and scientists. Each of these grants several bonus abilities. Among the Great People included are Aristotle, Plato, Moses, William Shakespeare, Ramakrishna, Michelangelo, Isaac Newton, Albert Einstein, and Marie Curie. (See List of historical figures in Civilization IV for a full list of people and cultures used in Civ IV.)
- The founding and spreading of religions and the adoption of a state religion (see above)
- Instead of subtracting from a city's population upon completion, Settler and Worker units require the city to suspend its population growth, on the theory that all its new citizens are being funneled into the unit, until it contains enough people to depart. This makes Settlers significantly more difficult to build in small cities, and encourages players to build up their cities before expanding.
- The concept of city maintenance replaces corruption, which has been removed. Civilizations with a large number of small or ineffective cities will find their empire too expensive to maintain.
- One civilization's units cannot cross another civilization's territory unless the civilizations are at war or have agreed to an open borders treaty, though there are special units (such as the spy and the caravel) which are able to cross borders with or without the open borders agreement.
- Governments have been replaced with a more flexible civics model, where the player can set the amount of freedom the citizens have (slavery, free speech, etc.). There are five different categories in the new civics model (Government, Legal, Labor, Economy, and Religion), and five separate options within each category. This appears to be adapted from the Social Engineering section of Sid Meier's Alpha Centauri.
- AI civilizations no longer act as if they have knowledge of the entire map. (In Civ2 they appeared to have only limited knowledge and could exchange maps.)
- The AI is more intelligent. It makes full use of all options and exhibits better long-term planning abilities.
- Barbarians now form cities, often named after their tribe or culture (Hun, Visigoth, etc.). These cities act and react like any other city: they send out worker units to improve terrain, can be captured or razed by military force, can be culture-flipped, and so on. However, they cannot be contacted via diplomacy. (In earlier games, barbarians could capture cities.) Their symbol on the flag is a white skull on a black field.
- Pollution, size restrictions, and similar aspects from earlier games are combined into one "City Health" system. Resources and improvements—such as wheat and hospitals—add health points, while population growth and industry decrease them. A negative total causes a food production penalty for the city. Fallout continues to exist in the case of a nuclear attack or meltdown.
- Similarly, cities no longer fall into disorder. For each unhappiness point over the amount of happiness points, one population point refuses to work, reducing the productivity of the city.
- Some streamlining elements have been introduced, such as the ability to select and issue orders to multiple units at the same time. When population grows, a new technology is discovered, or a new unit/improvement is built, any excess resources are carried over rather than wasted.
- Greater emphasis has been placed on the overall map-view mode. Where, in previous Civ games, a player was often forced to access the City Management screen, almost all of its functions have been integrated into (or made accessible via) the standard map view, as have many abilities (diplomacy, research topic selection, tax rate, etc.) that were formerly the domain of the Advisor screens. The game is almost totally playable from the map view alone.
- More emphasis has also been put on the game's soundtrack, which features compositions of Medieval, Renaissance, Baroque, Classical, Romantic and Minimalist origin, and self-composed pieces (mainly by Jeff Briggs). The main theme, "Baba Yetu," was written by Christopher Tin.
- Each leader has a unique piece of music played during diplomacy (with the exception of Kublai Khan, who shares his music with Genghis Khan). Many of the pieces are popular and familiar; for example, Roosevelt's music is the Marines' Hymn, and Napoleon's is a variant on La Marseillaise. Some are renditions of famous pieces of classical music, such as Frederick's piece, which is a paraphrase of the fourth of the Goldberg Variations, Barbarian's being "Polonaise," or Bismarck's, which is the opening theme of the second movement of Beethoven's Symphony No. 3. Others, such as Mao Zedong and Alexander the Great have music that has been modified from earlier games, such as Civilization III. Still others have entirely original scores.
- Narrative voice acting, previously heard in Sid Meier's Alpha Centauri but never used in a game with Civilization in its title, is provided by Leonard Nimoy, who reads a quotation related to a technology when it is discovered (technologies introduced in the expansion packs have their quotations read by Sid himself). Land-based units also offer short phrases in their culture's native language when selected. If the player's view is near a city, they will hear sounds related to the nation which owns that city.
- Sound effects are played when certain buildings or improvements are built, such as coins jingling when a bank is completed. Ambient sounds can also be heard near different terrains when zoomed in. For example, near the ocean or on its shore, waves splashing and breaking up can be heard.
- Civilization 4 uses the same 3D engine (Gamebryo) used in Sid Meier's Pirates!, which allows players to zoom smoothly from world map levels down to features in individual cities.
- Wonder movies have returned after being absent in Civilization III.
Official maps and scenarios
Sid Meier's Civilization IV included some bonus content, released with mainly the purpose of showing modding capabilities:
- Earth - This is the world map of the game. 124x68 tiles big, it features just 9 ancient civilizations. It is based on Robinson projection of the Earth, in order to optimize its size. Later, a 18 civilizations version was released, and being reckoned "flawless", it won the first prize at GameFlood modding contest.
- Earth Ice Age - This map is set in the world during the last ice age (20,000 years before present). 11 randomly-picked civilizations are contained in this map.
- Earth 1000 AD - 13 civilizations populate the world in this exact recreation of the Earth at the time of the Crusades.
- Greek World - To reenact the classical Mediterranean, a special map was made, based on Hecataeus's map of the world, as it was known by the Greeks. Extra detail is borrowed from other ancient maps such as Homer's, Herodotus's and Ptolemy's.
- Desert War - This scenario represents the Mediterranean theater of World War II. Axis and Allies have different cities as objective. They can win the game holding them for 10 turns.
- American Revolution - This scenario begins in 1775 AD. Player can side with American colonists or with the British Crown.
- Africa - this is a map added in v1.74 which contains an African continent with 9 randomly selected civilizations.
Civilization IV is much more open to modification than its predecessors. Game data and rules are stored in XML files, and a Software Development Kit was released in April 2006 to allow AI customization. Major parts of the interface, map generation, and scripted events are written entirely in Python and can be customised.
The World Builder allows a player to create a map from scratch, to use an in-game situation as a starting point for a new scenario, or to simply cheat by giving himself more units, gold, buildings, better relations with leaders, improvements, cultural borders, technologies, even take over other cities by placing a border there. The terrain can be altered, and resources, military units and cities on the map can be added, removed or modified. Additionally, each civilization's technological progress as well as its diplomatic and military ties to other civilizations can be edited. The World Builder for Civ IV is in-game, in contrast to previous Civilization games where the Map Editor was an external application. (In Civ2 one could modify anything using the cheat menu.)
World Builder can also be used to create an interesting experience. In custom game mode, the user must first turn all opposing civilizations off as well as all victory conditions. Barbarians must also be deactivated. In World Builder, the user can make it so that the player only starts with a settler with no starting technologies. This allows the user to progress through all technologies for a more expanded experience of the development of civilization.
- Editing 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.
At the current time the XML processing in Windows is more permissive of minor errors than in Mac OS X. As a result, some XML files which will work on the Windows version of the game need some slight tweaking before they function on the Macintosh version.
The game uses boost.python to allow the Python programming language access to many parts of the game (including the style and content of all interface screens). Python can also be used to modify random map generation and to add complex scripted events.
The version of Python present in the Windows version of the game differs from the version in Mac OS X up to and including version 10.4.7, and as a result, while most Python files for the Windows version will work on the Macintosh version, not all will.
Software Development Kit
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 completely re-write the game's DLL source code, enabling the modification of the game's AI and other integral parts of the game. 
As of the first official patch for the Macintosh version (v1.61 Revision A), there is no SDK for the Macintosh version of the game. In fact the Macintosh version lacks the separate library of game related code which the PC version uses, but instead includes the code compiled into the main executable. There is as of yet no indication of whether this will change in a future patch.
The release of Civilization IV did not go smoothly. Technical, production and shipping problems marred its product cycle.
- As originally shipped, the game functioned poorly on minimum-specification machines, and suffered from performance problems. It also conflicted with certain mainstream graphics cards. A user-created utility program was created to fix the memory usage problems. These problems were officially patched with version 1.52.
- Some considered the minimum specification unnecessarily high for what is ultimately a strategy game. In particular, many with laptops containing Intel graphics chipsets faced an issue due to a lack of Hardware Transform and Lighting features; however, the dependence upon this functionality seems to have been reduced with the release of recent patches.
- A major patch (v1.61) was released on 13 April, 2006. . The patch made a number of gameplay tweaks, fixes and additions, including five new scenarios and three new map scripts. The patch also added support for the Pitboss turn-based server application. As before, the 45.7 MB patch can be downloaded using the game's in-built updating utility, or from a variety of mirrors. 
- The most common packaging errors have been French and German technology charts in English-language boxes  and the erroneous packing of two of the same CD-ROM, rendering the game unusable. . 2K games has been replacing such shipments for free. Other copies have mislabeled disks; since this does not affect gameplay, users are asked to just use the right CD-ROM when applicable . There have also been some cases in which the game manual has pages placed in the wrong spot (e.g., page one is the very last page of the manual). There are also many typographical errors in the Dutch manual.
- Civ IV uses SafeDisc 4, which refuses to acknowledge legitimate game copies if certain programs associated with unauthorized copying are installed. Unofficial work-arounds to SafeDisc exist.
- Many players have experienced difficulty in multiplayer gameplay. When they attempt to join a game, their connection is refused by a fellow player's router or firewall, thus inhibiting gameplay. This problem is quite widespread in the Civ IV multiplayer community, and those players with routers or firewalls which reject other computers have been labeled as "bad peers." The problem is partially correctable by forwarding a series of ports on one's router or firewall to the game computer  (this method has not consistently solved the problem for some users), and can be eliminated entirely by demilitarizing the game computer on the router or firewall.
Despite all of these problems, many newer computers run Civilization IV quite smoothly. The headache caused by the need to cater to many different computer configurations has caused lead designer Soren Johnson to state that he seriously considers focusing on console development. 
- The v1.09 patch for Civilization IV was released on 23 November 2005. While it fixed some memory leak issues, the patch seemed to focus more on tweaks to buildings and units, while also creating some problems of its own.
- The v1.52 patch, released on 22 December 2005, was a major update that fixed several of the major performance headaches relating to numerous memory leaks and usage. v1.52 also added several new scenarios and maps, in addition to tweaking.
- On 13 April 2006, the v1.61 patch was released. Also a major update, it fixed several performance issues remaining from v1.09 and v1.52, including the stuttering Wonder movie problem. Several new additions were made to the game, including two new map scripts, new game options and new scenarios. Many gameplay tweaks were also made. Although the patch was considered a success for some users, others have reported various problems, including a loss of text and sound. These problems seem to be related to the incompatibility of certain mods downloaded by users.
Civilization IV is available for two different platforms currently, Windows (PC) and Macintosh.
The Macintosh version is published by Aspyr and was released in June 2006. Though it lacks some of the customization features which were added to the PC version in v1.61 and lacks support for the GameSpy internet gaming system, instead being compatible with the Mac specific GameRanger, it is otherwise identical to v.1.61 of the PC version. The game was released as a Universal binary, running on both x86 and PPC based Macintoshes.
Multiplayer games involving both versions of the game work, but require the use of one of the multiplayer options other than "Internet Play" due to the incompatible formats used by the two platforms.
- IGN 9.4/10 Editors' Choice Award 
- GameSpot 9.4/10 Editors' Choice Award 
- Eurogamer 9/10 
- GameSpy 5/5 
- Game-Revolution A- 
- Computer Gaming World 90/100 (5 November 2005) 
- ActionTrip 93/100 (5 November 2005) 
- The Bovine Conspiracy 10/10 (3 November 2005) 
- Newspaper: The Times 5/5 stars 
- Newspaper: Chicago Tribune 4/4 stars 
- Magazine: PC Gamer UK 92%
- Magazine: PC Gamer 94%
- Magazine: PC Powerplay (German): 91%
- Magazine: PC ZONE (UK): 92%
- Magazine: Giochi per il mio Computer (Italian): 9/10
- Magazine: SuperPlay (Swedish) 10/10
- Magazine: PC Powerplay (Australian) : 10/10
- Magazine: Pelit (Finnish) : 97/100
- Magazine: Hyper (Australian) : 96%
- Magazine: Atomic MPC (Australian) : 10/10
- Magazine: Quantaz (Canadian) : 99%
- Magazine: CD-Action (Polish) : 9/10
- Television: X-Play 5/5
- IGN: PC Game of the Year 2005, Best Strategy Game 2005, Best Online Game 2005
- GameSpy: PC Game of the Year 2005, Best Turn-Based Strategy Game 2005, Game of the Year 2005
- GameSpot: Best Strategy Game 2005, Best PC Game 2005
- Time Magazine: Top Pick (E3 2005)
- Scripps Howard News Service: Game of the Year 2005 (PC)
- For other awards click here.
- Sid Meier narrates the tutorial.
- Much of the game is voiced by Leonard Nimoy, famous for playing the role of Spock from Star Trek.
- In the cultural victory cutscene, the Colossus' face appears to be a composite of Sid Meier.
- The manual went into production before the developers finished the game, and there are several notable errors:
- All the results of all the games that have been played, regardless of victory or score, are listed in the "Hall of Fame" (despite what the manual says: If your victory is spectacular enough, your exploits might be recorded on the Civilization IV Hall of Fame screen).
- The Three Gorges Dam has replaced the Hoover Dam, which was the Wonder used in previous versions of the game.
- Elvis Presley has had some form of appearance in every Civilization title so far: in Civilization IV, the clothes of the Great Artist units, from the Industrial to the Modern Eras, and the Rock 'n' Roll wonder are tributes to him.
- Spaceship journeys to Alpha Centauri are always successful.
- In the video for the Space Victory, the figure that jumps down resembles CEO Nwabudike Morgan from Sid Meier's Alpha Centauri.
- The animation shown when beginning a new game (commencing with words In the beginning, the Earth was without form, and void...) is a tribute to original Civilization game, where very similar animation accompanied with the same text was played. See here for the full text.
- The name of the title song played at the start of the game is Baba Yetu. The title means "Our Father" in Swahili, and the song itself is a rendition of the Christian Lord's Prayer. It is performed by Stanford University's Talisman A Cappella and was composed by Christopher Tin. (sample, full song, lyrics, and more information)
- In the popup which tells the player that they have reached the Modern Era, there is a digital watch with the brand name Soren. This is a reference to Soren Johnson, the lead designer and AI programmer for the game. The time shown on the watch is 05:23, and Soren's birthday is May 23 (05/23).
- The Firaxis logo is the artwork on the sails of Work Boats.
- In a reference to a famous Al Gore quotation, the former Vice President's face is featured in the graphic for The Internet.
- In the movie for the Hollywood wonder, the blueprints include a picture of Clara Bow and a Hollywood Walk of Fame star for Hoot Gibson.
- When the player is at war with France against Louis XIV and he refuses an offer to end the war, he occasionally says, "It is too late for peace, you silly (your nation here)! Now go away or I shall taunt you a second time!" This is referring to the French Taunters in Monty Python and the Holy Grail. It made even more evident if the player is playing as the English civilization, since in the movie, the French Taunters also said "Silly English K-nnnigets."
- When the player is at war with America against Roosevelt and he refuses an offer to end the war, he occasionally says, "America does not negotiate with terrorists."
- When starting or loading a game hints will pop up in the bottom of the screen. Such hints include: "Never start a land war in Asia", "Snacks are good in moderation" and "Never bring a sword to a gunfight".
- When zoomed close to an American city, fifes and drums playing can be heard. The sequence is a remake from another Sid Meier game, Colonization.
- A promotional website for a fictional group called "Civilization Anonymous" (a parody of Alcoholics Anonymous) was put on the internet and advertised in gaming magazines prior to the game's release.
- When selecting what size and style of map a player wants to use in a new game, a globe with seemingly random land masses rotates in a space within the selection window. The globe is actually an upside-down planet earth with oceans in the shape of earth's continents.
- In the movie for the Kremlin wonder, the building shown is not the Moscow Kremlin, but Saint Basil's Cathedral instead. The part of the "real" Kremlin is seen at the end of the movie on the right side.
- The graphic model and image for the Masjid Al-Haram is not the real mosque, but the Dome of the Rock, which is located in Jerusalem near the Masjid al-Aksa, the third holy mosque.
- Civilization IV Official Strategy Guide. BradyGames. October 25, 2005. ISBN 0-7440-0580-9.
- The sites listed below.
- Finnish translation
- Russian translation
- $39.99 (about $US28) for the complete game (with both expansion packs) at Noel Leeming, Porirua, Dec 2009
- $13.99 for the complete game (August 2015, at Amazon)
- $6.00 for the complete game in download (August 2015, at Amazon)
- €10.00 for the complete game (with both expansion packs), March 2011