Sid Meier's Civilization is a 1991 turn-based strategy 4X video game developed and published by MicroProse. The game was originally developed for MS-DOS running on a PC, and has undergone numerous revisions for various platforms. The player is tasked with leading an entire human civilization over the course of several millennia by controlling various areas such as urban development, exploration, government, trade, research, and military. The player can control individual units and advance the exploration, conquest and settlement of the game's world. The player can also make such decisions as setting forms of government, tax rates and research priorities. The player's civilization is in competition with other computer-controlled civilizations, with which the player can enter diplomatic relationships that can either end in alliances or lead to war.
Civilization is a turn-based single-player strategy game. The player takes on the role of the ruler of a civilization, starting with one (or occasionally two) settler units, and attempts to build an empire in competition with two to seven other civilizations. The game requires a fair amount of micromanagement (although less than other simulation games). Along with the larger tasks of exploration, warfare and diplomacy, the player has to make decisions about where to build new cities, which improvements or units to build in each city, which advances in knowledge should be sought (and at what rate), and how to transform the land surrounding the cities for maximum benefit. From time to time the player's towns may be harassed by barbarians, units with no specific nationality and no named leader. These threats only come from huts, unclaimed land or sea, so that over time and turns of exploration, there are fewer and fewer places from which barbarians will emanate.
Before the game begins, the player chooses which historical or current civilization to play. In contrast to later games in the Civilization series, this is largely a cosmetic choice, affecting titles, city names, musical heralds, and color. The choice does affect their starting position on the "Play on Earth" map, and thus different resources in one's initial cities, but has no effect on starting position when starting a random world game or a customized world game. The player's choice of civilization also prevents the computer from being able to play as that civilization or the other civilization of the same color, and since computer-controlled opponents display certain traits of their civilizations this affects gameplay as well. The Aztecs are both fiercely expansionist and generally extremely wealthy, for example. Other civilizations include the Americans, the Mongols, and Romans. Each civilization is led by a famous historical figure, such as Mahatma Gandhi for India.
As time advances, new technologies are developed; these technologies are the primary way in which the game changes and grows. At the start, players choose from advances such as pottery, the wheel, and the alphabet to, near the end of the game, nuclear fission and spaceflight. Players can gain a large advantage if their civilization is the first to learn a particular technology (the secrets of flight, for example) and put it to use in a military or other context. Most advances give access to new units, city improvements or derivative technologies: for example, the chariot unit becomes available after the wheel is developed, and the granary building becomes available to build after pottery is developed. The whole system of advancements from beginning to end is called the technology tree, or simply the Tech tree; this concept has been adopted in many other strategy games. Since only one tech may be "researched" at any given time, the order in which technologies are chosen makes a considerable difference in the outcome of the game and generally reflects the player's preferred style of gameplay.
Players can also build Wonders of the World in each of the epochs of the game, subject only to obtaining the prerequisite knowledge. These wonders are important achievements of society, science, culture and defense, ranging from the Pyramids and the Great Wall in the Ancient age, to Copernicus' Observatory and Magellan's Expedition in the middle period, up to the Apollo program, the United Nations, and the Manhattan Project in the modern era. Each wonder can only be built once in the world, and requires a lot of resources to build, far more than most other city buildings or units. Wonders provide unique benefits to the controlling civilization. For example, Magellan's Expedition increases the movement rate of naval units. Wonders typically affect either the city in which they are built (for example, the Colossus), every city on the continent (for example, J.S. Bach's Cathedral), or the civilization as a whole (for example, Darwin's Voyage). Some wonders are made obsolete by new technologies.
One positive aspect both had taken from Railroad Tycoon was the idea of multiple smaller systems working together at the same time and the player having to manage them. Both Meier and Shelley recognized that the complex interactions between these systems led players to "make a lot of interesting decisions", and that ruling a whole civilization would readily work well with these underlying systems. Some time later, both discussed their love of the original Empire computer games, and Meier challenged Shelley to give him ten things he would change about Empire; Shelley provided him with twelve. Around May 1990, Meier presented Shelley with a 5-1/4" floppy disk which contained the first prototype of Civilization based on their past discussions and Shelley's list.
Civilization was released with only single-player support, with the player working against multiple computer opponents. In 1991, Internet or online gaming was still in its infancy, so this option was not considered in Civilization's release. Over the next few years, as home Internet accessibility took off, MicroProse looked to develop an online version of Civilization. This led to the 1995 release of Sid Meier's CivNet. CivNet allowed for up to seven players to play the game, with computer opponents available to obtain up to six active civilizations. Games could be played either on a turn-based mode, or in a simultaneous mode where each player took their turn at the same time and only progressing to the next turn once all players have confirmed being finished that turn. The game, in addition to better support for Windows 3.1 and Windows 95, supported connectivity through LAN, primitive Internet play, modem, and direct serial link, and included a local hotseat mode. CivNet also included a map editor and a "king builder" to allow a player to customize the names and looks of their civilization as seen by other players.
An Easter egg named "Nuclear Gandhi" in most of the games in the series references a supposed integer overflow bug in Civilization that causes a computer-controlled Gandhi, normally a highly peaceful leader, to become a nuclear warmonger. The game is said to start Gandhi's "aggression value" at 1 out of a maximum 255 possible for an 8-bit unsigned integer, making a computer-controlled Gandhi tend to avoid armed conflict. However, once a civilization achieves democracy as its form of government, its leader's aggression value falls by 2. Under normal arithmetic principles, Gandhi's "1" would be reduced to "-1", but because the value is an 8-bit unsigned integer, it wraps around to "255", causing Gandhi to suddenly become the most aggressive opponent in the game. Interviewed in 2019, developer Brian Reynolds said with "99.99% certainty" that this story was apocryphal, recalling Gandhi's coded aggression level as being no lower than other peaceful leaders in the game, and doubting that a wraparound would have had the effect described. He noted that all leaders in the game become "pretty ornery" after their acquisition of nuclear weapons, and suggested that this behaviour simply seemed more surprising and memorable when it happened to Gandhi. Meier, in his autobiography, stated "That kind of bug comes from something called unsigned characters, which are not the default in the C programming language, and not something I used for the leader traits. Brian Reynolds wrote Civ II in C++, and he didn't use them, either. We received no complaints about a Gandhi bug when either game came out, nor did we send out any revisions for one. Gandhi's military aggressiveness score remained at 1 throughout the game." He then explains the overflow error story was made up in 2012. It spread from there to a Wikia entry, then eventually to Reddit, and was picked up by news sites like Kotaku and Geek.com.
Another relic of Civilization was the nature of combat where a military unit from earlier civilization periods could remain in play through modern times, gaining combat bonuses due to veteran proficiency, leading to these primitive units easily beating out modern technology against all common sense, with the common example of a veteran phalanx unit able to fend off a battleship. Meier noted that this resulted from not anticipating how players would use units, expecting them to have used their forces more like a war-based board game to protect borders and maintain zones of control rather than creating "stacks of doom". Future civilization games have had many changes in combat systems to prevent such oddities, though these games do allow for such random victories.
An open source clone of Civilization has been developed under the name of Freeciv, with the slogan "'Cause civilization should be free." This game can be configured to match the rules of either Civilization or Civilization II. Another game that partially clones Civilization is a public domain game called C-evo. 2b1af7f3a8