''Freeciv'' is a
single- and
multiplayer
A multiplayer video game is a video game in which more than one person can play in the same game environment at the same time, either locally on the same computing system ( couch co-op), on different computing systems via a local area network, or ...
turn-based strategy
A turn-based strategy (TBS) game is a strategy game (usually some type of wargame, especially a strategic-level wargame) where players take turns when playing. This is distinguished from real-time strategy (RTS), in which all players play si ...
game for
workstation
A workstation is a special computer designed for technical or scientific applications. Intended primarily to be used by a single user, they are commonly connected to a local area network and run multi-user operating systems. The term ''worksta ...
s and
personal computer
A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or tech ...
s inspired by the
proprietary ''
Sid Meier's Civilization'' series. It is available for most desktop computer
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs.
Time-sharing operating systems scheduler (computing), schedule tasks for ef ...
s and available in an online
browser version.
Released under the
GNU GPL-2.0-or-later, Freeciv is
free and open source software
Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software and open-source software where anyone is freely licensed to use, copy, study, and change the software in any way, and the source ...
. The game's default settings are closest to ''
Civilization II
''Sid Meier's Civilization II'' is a turn-based strategy video game in the Civilization (series), ''Civilization'' series, developed and published by MicroProse. It was released in 1996 for personal computer, PCs, and later ported to the PlayS ...
'', in both gameplay and graphics, including the units and the
isometric
The term ''isometric'' comes from the Greek for "having equal measurement".
isometric may mean:
* Cubic crystal system, also called isometric crystal system
* Isometre, a rhythmic technique in music.
* "Isometric (Intro)", a song by Madeon from ...
grid. However, with a lot of multiplayer games being played in longturn communities, rulesets and additional variants have evolved away from the original ruleset. Freeciv is playable online a
Longturn.netfciv.netfreecivweb.organd a number of temporary private servers that may or may not be listed on metaserver.
Players take the role of tribal leaders in
4000 B.C.
The 4th millennium BC spanned the years 4000 BC to 3001 BC. Some of the major changes in human culture during this time included the beginning of the Bronze Age and the invention of writing, which played a major role in starting recorded history. ...
who must guide their peoples through the centuries. Over time, new technologies are discovered, which allow the construction of new city buildings and the deployment of new units. Players can wage war on one another or form diplomatic relationships.
The game ends when one civilization has eradicated all others or accomplished the goal of
space colonization
Space colonization (also called space settlement or extraterrestrial colonization) is the use of outer space or celestial bodies other than Earth for permanent habitation or as extraterrestrial territory.
The inhabitation and territor ...
, or at a given deadline. If more than one civilization remains at the deadline, the player with the highest score wins. Points are awarded for the size of a civilization, its wealth, and cultural and scientific advances.
History
At the
computer science
Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to practical disciplines (includin ...
department at
Aarhus University
Aarhus University ( da, Aarhus Universitet, abbreviated AU) is a public research university with its main campus located in Aarhus, Denmark. It is the second largest and second oldest university in Denmark. The university is part of the Coimbra G ...
, three students, avid players of ''
XPilot'' and of
Sid Meier’s ''
Civilization
A civilization (or civilisation) is any complex society characterized by the development of a state, social stratification, urbanization, and symbolic systems of communication beyond natural spoken language (namely, a writing system).
C ...
'', which was a stand-alone PC game for
MS-DOS
MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few oper ...
, decided to find out whether the two could be fused into an
X-based multiplayer ''Civilization''-like strategy game. The students—Peter Unold, Claus Leth Gregersen and Allan Ove Kjeldbjerg—started development in November 1995;
the first playable version was released in January 1996, with bugfixing and small enhancements until April. The rules of the game were close to ''Civilization'', while the client/server architecture was basically that of ''XPilot''.

For the developers, ''Freeciv'' 1.0 was a successful
proof of concept
Proof of concept (POC or PoC), also known as proof of principle, is a realization of a certain method or idea in order to demonstrate its feasibility, or a demonstration in principle with the aim of verifying that some concept or theory has prac ...
, but a rather boring game, so they went back to ''XPilot''. Other players and developers took over; they made the game available on many other operating systems, including
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which i ...
,
Solaris,
Ultrix,
Amiga OS
AmigaOS is a family of proprietary native operating systems of the Amiga and AmigaOne personal computers. It was developed first by Commodore International and introduced with the launch of the first Amiga, the Amiga 1000, in 1985. Early versio ...
, and
Microsoft Windows.
Linux distributions started to include ''Freeciv''.
The main development goal remained to make a ''Civilization''-like game playable over the Internet, with participants on different continents, even when connected with
14400 bit/s modem
A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by modulating one or more c ...
s. ''Freeciv'' achieved this by using an
asynchronous client-server protocol: during each turn, human users play concurrently, and their actions are sent to the server for processing without awaiting the results. This kept the game playable with
network latency
Network delay is a design and performance characteristic of a telecommunications network. It specifies the Latency (engineering), latency for a bit of data to travel across the network from one communication endpoint to another. It is typically ...
up to a few hundreds of milliseconds.
In 1998, computer players were added; they could soon beat newcomers to the game with ease, using only minor forms of cheating. Computer players are implemented directly in the server; they do not play concurrently with human players, but separately, in between turns.
The game grew in popularity. A public server was installed on which games could be played around the clock; it retained the games and published a post-game analysis webpage with per-player statistics and an animated map replay.
Subsequent 1.x releases improved the GUI, improved the gameplay, optimized playability over poor connections, and added many small features.
Over time, the
winning strategy proved to be ''city smallpox'', i.e. sprawling the map with many small cities as fast as possible; whoever could develop fastest would win the game, and growing and developing individual cities was not worthwhile.
In practice, from around 2002, experienced players would form teams at the start of the game; a
fork of ''Freeciv'' included specific features for team play.
Version 2.0, released in 2005, introduced several important changes.
New team playing features and advanced diplomacy made cooperative gaming more attractive.
Adjustments to various costs and benefits put an end to the dominance of the city smallpox strategy that left many of the game's features unused; developing one's empire now necessitated a careful plan for city development, including the used of trade routes and phases of ''rapture'', in which city populations grow quickly, under relatively peaceful conditions.
As a result, multiplayer games were almost always played in teams and typically took longer to finish when compared to 1.x games.
In 2006,
TCP
TCP may refer to:
Science and technology
* Transformer coupled plasma
* Tool Center Point, see Robot end effector
Computing
* Transmission Control Protocol, a fundamental Internet standard
* Telephony control protocol, a Bluetooth communication s ...
and
UDP port number 5556 was assigned to ''Freeciv'' by
IANA
The Internet Assigned Numbers Authority (IANA) is a standards organization that oversees global IP address allocation, autonomous system number allocation, root zone management in the Domain Name System (DNS), media types, and other Interne ...
. In 2017, after being hosted on
Gna! for 15 years, ''Freeciv'' moved its
source repository to
GitHub
GitHub, Inc. () is an Internet hosting service for software development and version control using Git. It provides the distributed version control of Git plus access control, bug tracking, software feature requests, task management, co ...
.
Reception and impact
In 2000
CNN placed ''Freeciv'' among the "Top 10 Linux games for the holidays". In 2005, in an
O'Reilly article on "Open Source Mac Gaming", ''Freeciv'' was recommended. In 2008 ''
APC'' named Freeciv among the "Top 5 best (free) open source games".
''
Linux Format'' selected it as "HotPick" in April 2010 and in October 2014.
''Freeciv'' was described as an example in ''
The Art of Unix Programming'' by
Eric S. Raymond. Studies and courses have used ''Freeciv'' as a platform for experimenting with the design and programming of
intelligent agent
In artificial intelligence, an intelligent agent (IA) is anything which perceives its environment, takes actions autonomously in order to achieve goals, and may improve its performance with learning or may use knowledge. They may be simple or c ...
s. In 2016 ''Freeciv'' was used as a challenge after
chess
Chess is a board game for two players, called White and Black, each controlling an army of chess pieces in their color, with the objective to checkmate the opponent's king. It is sometimes called international chess or Western chess to dist ...
and
Go for a commercial AI.
Design
Freeciv is very configurable, down to the specific rules, so it can be played in Freeciv (default) mode, ''
Civilization
A civilization (or civilisation) is any complex society characterized by the development of a state, social stratification, urbanization, and symbolic systems of communication beyond natural spoken language (namely, a writing system).
C ...
'' mode, ''
Civilization II
''Sid Meier's Civilization II'' is a turn-based strategy video game in the Civilization (series), ''Civilization'' series, developed and published by MicroProse. It was released in 1996 for personal computer, PCs, and later ported to the PlayS ...
'' mode, or a custom mode. One or several players act as game administrators and can configure the game rules. Typically modified rules are:
* Number of players required before the game can be started. The maximum number of players is 126 in the latest version of Freeciv.
* Speed of technological development
* Whether there should be computer controlled players
* Whether (computer controlled)
barbarian
A barbarian (or savage) is someone who is perceived to be either uncivilized or primitive. The designation is usually applied as a generalization based on a popular stereotype; barbarians can be members of any nation judged by some to be less ...
s should invade player settlements
* How close cities can be built to one another
* How continents and islands are generated and distributed over the map
* The map size, where the maximum map size is
2,048,000 map tiles (128,000 before 2.4.0)
* Map topology (rectangular or hexagonal tiling; whether it wraps horizontally and/or vertically)
In order to play a game of Freeciv, a user must start up a Freeciv
client
Client(s) or The Client may refer to:
* Client (business)
* Client (computing), hardware or software that accesses a remote service on another computer
* Customer or client, a recipient of goods or services in return for monetary or other valuabl ...
and connect it to a Freeciv
server. Initially, the server is in pre-game phase; in this phase, clients can connect and game configuration parameters can be changed. At some point, the server may be ordered to start a game; in response, it creates game players (nations) and the game map, and assigns every player to either a Freeciv client or a computer player, as specified by the configuration. From that point on, the game will run until it ends or is terminated; the server can never get back into pre-game state. The user can also start a game directly from the client: this automatically starts a Freeciv server, connects to it and starts the game.
Features

Freeciv's graphics system is configurable: originally, map display was always in overhead mode (like in ''
Civ I'').
Isometric
The term ''isometric'' comes from the Greek for "having equal measurement".
isometric may mean:
* Cubic crystal system, also called isometric crystal system
* Isometre, a rhythmic technique in music.
* "Isometric (Intro)", a song by Madeon from ...
mode (like in ''
Civ II'' and ''
III
III or iii may refer to:
Companies
* Information International, Inc., a computer technology company
* Innovative Interfaces, Inc., a library-software company
* 3i, formerly Investors in Industry, a British investment company
Other uses
* Ins ...
'') and optionally
hexagonal tiling
In geometry, the hexagonal tiling or hexagonal tessellation is a regular tiling of the Euclidean plane, in which exactly three hexagons meet at each vertex. It has Schläfli symbol of or (as a truncated triangular tiling).
English mathema ...
(like in ''
Civ V'' and ''
VI'') were added later. In both modes, look can be further customized by switching to an alternative set of graphics (called a ''
tileset''). The sounds can be replaced as well. Freeciv supports human-to-human multiplayer gameplay and
artificial intelligence
Artificial intelligence (AI) is intelligence—perceiving, synthesizing, and inferring information—demonstrated by machine
A machine is a physical system using Power (physics), power to apply Force, forces and control Motion, moveme ...
(AI) computer players. While the game is turn based, human players move simultaneously. The AI players move separately, partly at the start of a turn, partly at the end.
In releases before 2.0, AI players could not engage in diplomatic relationships with human players. Under the current releases, AI players will engage in a very predictable, rules-based diplomacy. Version 2.2.0 included a map editor, termed Civworld. It can create new scenarios, as well as edit the map currently being played. Basic scripting is available with Freeciv, but is not available in Civworld. Version 2.3 increased the limit of players from 30 to 126.
There are different clients available
SDL,
GTK+
GTK (formerly GIMP ToolKit and GTK+) is a free and open-source cross-platform widget toolkit for creating graphical user interfaces (GUIs). It is licensed under the terms of the GNU Lesser General Public License, allowing both free and prop ...
(version3) and
Xaw3D A
Qt client was added in version 2.5. The Freeciv interface is available in over 30 different languages. The addition of Gaelic was covered on
BBC TV
BBC Television is a service of the BBC. The corporation has operated a public broadcast television service in the United Kingdom, under the terms of a royal charter, since 1927. It produced television programmes from its own studios from 19 ...
.
Ports and variants
Originally developed on
IRIX
IRIX ( ) is a discontinued operating system developed by Silicon Graphics (SGI) to run on the company's proprietary MIPS workstations and servers. It is based on UNIX System V with BSD extensions. In IRIX, SGI originated the XFS file system ...
, Freeciv has been ported to many different operating systems: it is distributed with many
Linux distribution
A Linux distribution (often abbreviated as distro) is an operating system made from a software collection that includes the Linux kernel and, often, a package management system. Linux users usually obtain their operating system by downloading on ...
s, offers installers for
Microsoft Windows, and has been known to run on
Mac OS X
macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and lapt ...
,
MorphOS
MorphOS is an AmigaOS-like computer operating system (OS). It is a mixed proprietary and open source OS produced for the Pegasos PowerPC (PPC) processor based computer, PowerUP accelerator equipped Amiga computers, and a series of Freescale devel ...
,
Solaris,
Ultrix,
QNX,
OS/2
OS/2 (Operating System/2) is a series of computer operating systems, initially created by Microsoft and IBM under the leadership of IBM software designer Ed Iacobucci. As a result of a feud between the two companies over how to position OS/2 ...
,
Cygwin,
AmigaOS,
AROS,
RISC OS
RISC OS is a computer operating system originally designed by Acorn Computers Ltd in Cambridge, England. First released in 1987, it was designed to run on the ARM chipset, which Acorn had designed concurrently for use in its new line of Archi ...
,
Maemo
Maemo is a software platform originally developed by Nokia, now developed by the community, for smartphones and Internet tablets. The platform comprises both the Maemo operating system and SDK. Maemo played a key role in Nokia's strategy to c ...
,
ZETA
Zeta (, ; uppercase Ζ, lowercase ζ; grc, ζῆτα, el, ζήτα, label=Demotic Greek, classical or ''zē̂ta''; ''zíta'') is the sixth letter of the Greek alphabet. In the system of Greek numerals, it has a value of 7. It was derived fr ...
,
SkyOS, various
BSDs, and smartphones and tablets running
Android
Android may refer to:
Science and technology
* Android (robot), a humanoid robot or synthetic organism designed to imitate a human
* Android (operating system), Google's mobile operating system
** Bugdroid, a Google mascot sometimes referred to ...
.
As of version 2.4,
Mac OS X
macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and lapt ...
, and as of version 2.3, Windows versions older than
Windows XP
Windows XP is a major release of Microsoft's Windows NT operating system. It was release to manufacturing, released to manufacturing on August 24, 2001, and later to retail on October 25, 2001. It is a direct upgrade to its predecessors, Wind ...
SP3 are no longer supported. Freeciv is available in the
PortableApps format.
Freeciv21
Freeciv21 is a fork of the original Freeciv project started with the intention of modernising the code and the client interface, and also adjusting the software more to the needs of multiplayer longturn variant. It was started by enthusiasts within th
Longturn.netcommunity. As of January 2023 it is in late developing stage. The first standard Longturn game played on Fc21 software was LT75, started in November 2022.
Freeciv-web

Freeciv-web is a version of Freeciv playable online in any modern
web browser
A web browser is application software for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's screen. Browsers are used on ...
. It supports 2D isometric graphics or 3D graphics using WebGL. The game is a fork of the Freeciv project, with the goal of redesigning the desktop game into a version which can be played online. Freeciv-web introduced several new features, such as play-by-email support freely available to anyone online, and support for playing the game on any real-world map location by choosing a map using Mapbox, which is not available in commercial games in the genre. The game's default settings are closest to ''
Civilization II
''Sid Meier's Civilization II'' is a turn-based strategy video game in the Civilization (series), ''Civilization'' series, developed and published by MicroProse. It was released in 1996 for personal computer, PCs, and later ported to the PlayS ...
'', both in gameplay and graphics (including the units and the
isometric
The term ''isometric'' comes from the Greek for "having equal measurement".
isometric may mean:
* Cubic crystal system, also called isometric crystal system
* Isometre, a rhythmic technique in music.
* "Isometric (Intro)", a song by Madeon from ...
grid). The proposal to create a web-version of Freeciv was made 6 April 2007 on the Freeciv mailing lists, and documented on the Freeciv.org wiki. Freeciv-web was originally created by Andreas Røsdal, but is now maintained by several Freeciv developers on GitHub.
Freeciv-web is
free and open source software
Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software and open-source software where anyone is freely licensed to use, copy, study, and change the software in any way, and the source ...
. The Freeciv C server is released under the
GNU General Public License
The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end user
In product development, an end user (sometimes end-user) is a person who ultimately uses or is intended to ulti ...
, while the Freeciv-web client is released under the
GNU Affero General Public License. Freeciv-web supports human-to-human multiplayer gameplay and
artificial intelligence
Artificial intelligence (AI) is intelligence—perceiving, synthesizing, and inferring information—demonstrated by machine
A machine is a physical system using Power (physics), power to apply Force, forces and control Motion, moveme ...
(AI) computer players. Its features are similar to the Freeciv C client, although not all of the user-interface has been ported from the C client yet.
The Freeciv-web server on play.freeciv.org was shut down in March 2018, but the project was revived by a group of volunteers on freecivweb.org. Freeciv-web can be played online at a number of servers such as freecivweb.org.
All the features required to play a full game of Freeciv are in place. Most servers offer multiple varieties of the game: single-player, multiplayer free-for-all, play-by-email and
longturn.
Longturn variants
Freeciv ''Longturn'' is a specialized large-group-multiplayer-online-strategy variant of Freeciv featuring daylong game turns with large amounts of human opponents per map, allowing for optimal timing to build up strategic plans and readapt them to the circumstances of each turn. Matches can last anytime from a few weeks to months, and commonly involve 20 to 30 players in each one.
Longturn's first game, now called LT0, started around 2004 on the Polish Civilization fanpage civ.org.pl and is now conducted a
Longturn.net It was decided that the game is a bit too slow-paced, so a new "3X movement" ruleset was devised – basically, all units had their movement points and vision radius tripled. As of December 2022, the latest game was LT76. Changes to settings or rulesets are discussed in the Longturn forum. and, recently
Longturn Discord serverwhere the community is currently centered. There is ongoing development of a few non-standard rulesets specifically adjusted for longturn multiplayer games, diverging from the rules of the original Civilization which was created as a single-player game.
''Greatturn'' was a similar concept on another server. ''FreeCivWeb.org''
also offers longturn games (more than fifty have been played before mid-2021) with a multiplayer ruleset which is documented in great details
''Power of Planets - Earth'' (formerly known as ''GaCivs'') is a free-to-play MMO-RTS variant based on FreeCiv. The ruleset was devised to support long-term time-based gameplay instead of turn-based strategy.
See also
*
List of free and open-source software packages
*
List of open source video games
References
External links
*
*
*
{{authority control
1996 video games
4X video games
Acorn Archimedes games
Amiga games
AmigaOS 4 games
AROS software
Articles containing video clips
Browser games
Cooperative video games
Cross-platform software
Free and open-source Android software
Free software that uses SDL
Linux games
Lua (programming language)-scripted video games
Maemo games
MorphOS games
Multiplayer hotseat games
Open-source video games
Strategy video games
MacOS games
Panhistorical video games
Turn-based strategy video games
Video games developed in Denmark
Video games with isometric graphics
Windows games