Freeciv Server is an engine that allows creating and playing multiple uniquely different games. Each game has a uniquely different set of programmed rules.

A ruleset specifies the set of rules for a particular game. The ruleset describes the complete behaviour of the game. The freeciv server processes the ruleset to determine the attributes of units, cities, buildings, inventions, wonders and much more. There is one main rules file holding a bunch of common rules and a collection of references to more specific rules files.


These are the rulesets as packaged in the official release.


The Civ1 ruleset emulates Civilization I behavior.


The Civ2 ruleset emulates Civilization II behavior.


The Civ2civ3 ruleset's main purpose is a much simpler game similar to civ3, using the civ2 combat system. Cutting disadvantages from less optimal play makes it easier for beginners. Features that were strategically exploited for advantage are removed, such as rapture growth, trade routes, and the advantages of advanced governments. The result is a simpler linear development, and a slower game. With less advantage in later governments to balance out their bulb cost, timing and choice in government becomes relaxed and of much less strategic concern. Terrain complexity is smoothed: Hill cities get 2/2/0, making hills the obvious choice for most cities—this reduces exploiting advantage from optimal city placement and is beginner-friendly in edging game balance more toward defense. The removal of rapture eliminates strategic complexity in exploiting advantage from optimally managed trade ratios, while also diminishing the functional advantages that can be exploited from buildings and wonders affecting trade, luxury, and happiness. All the new rules are intended so AI can play with them.


The Classic ruleset is the traditional standard Freeciv ruleset, and default for single player games.


The Experimental ruleset tries to use the new features available in Freeciv that are not yet in use in default rulesets. It is based on the classic ruleset. If the changes in this ruleset result in a working game (especially with regard to the AI) they could be included in the default ruleset for next major release.


The Multiplayer ruleset rectifies game balance issues encountered in the Classic ruleset. Multiplayer rules were intended to be the most 'standard' or 'classic' ruleset possible while still resolving known issues. The changes were meant to balance games that had much larger numbers of players. It is based on the 'Rewonder' ruleset designed by Madeline Book for Freeciv 2.1.


The Multiplayer+ ruleset further rectifies bugs, exploits, and imbalances, as vetted from years of play in the Multiplayer ruleset. It is essentially a fixed Multiplayer ruleset that is the same in almost all other respects. This ruleset is currently only available on the multiplayer gaming community Freeciv-web. There, it is accessible by the console command line /rules mpplus

Multiplayer II Evolution[]

The Multiplayer II "Evolution" ruleset started with Multiplayer+ as its basis. It strives to keep familiarity, mechanics, look-and-feel, and game balance with the "ancestral tree" of Civ II ⸙ Classic ⸙ Multiplayer ⸙ Multiplayer+. It is much more ambitious in introducing major upgrades, features, and improvements to modernize the game, selectively taking superior features out of modern improvements to the genre. As such, it is currently the preferred ruleset for the Multiplayer branch of Freeciv. This ruleset is currently only available on the multiplayer gaming community Freeciv-web. There, it is accessible by the console command line /rules mp2
  • Multiplayer II Avant-Garde is the 1.1 release of mp2 rules, accessible with /rules ag
  • Multiplayer II Brava is the 1.2 release of mp2 rules, accessible with /rules mp2-brava
  • Future releases of Multiplayer II can be recognized by each release having a moniker using alphabetical A,B,C order.


The Sandbox ruleset is for playing with game engine features, and is not assured to maintain savegame compatibility between even bugfix releases. It is currenly based on Civ2civ3. It is useful for ruleset developers to experiment with new ruleset mechanics.

Anatomy of a Ruleset[]

Ruleset files define the rules of the game within the hard-coded framework:


Improvements, Wonders, Small Wonders, and Special buildings like Coinage are defined here. See Editing Buildings for more information.


City properties are defined here. See Editing Cities for more information.


Game effects are defined here and its included sub-file, ai_effects.ruleset. See Editing Effects for more information.


Various general game rules, action enablers, and first 32 default player colors are defined here. See Editing Game for more information.


Governments are defined here. See Editing Governments for more information.


Nations are defined here. The list of included nations, nation groups, and nation sets in the included nationlist.ruleset are defined here. See Editing Nations for more information.


Civilization Styles are defined here. See Editing Styles for more information.


Advances and Technology Flags are defined here. See Editing Techs for more information.


Terrain, Special Resources, Roads, and other Extras are defined here. See Editing Terrain for more information.


Unit Classes, Unit Class Flags, Unit Flags, and Units are defined here. See Editing Units for more information.

LUA File[]

Script.lua and the included default.lua can have events defined within them. See Event Scripting for more information.

Serv File[]

Serv Files contain server commands, especially the rulesetdir that tells the server to load a ruleset's directory. The name.serv file for a given ruleset name are stored in a directory found in the FREECIV_DATA_PATH together with a name sub-directory containing all *.ruleset files and script.lua as listed above.

See also[]

Game Anatomy & Modding
Event ScriptingEditing RulesetsEditing TilesetsMore RulesetsMore Tilesets
Editing Rulesets
Editing BuildingsEditing CitiesEditing EffectsEditing GameEditing Governments
Editing NationsEditing StylesEditing TechsEditing TerrainEditing Units