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The Civ4TechInfos file defines all of the information, basic and complex, about each of the game's technologies. Information in this file includes a tech's prerequisites, research cost, and benefits.

All tags must be opened and closed; the first is the "open", the second the "close" tag. If nothing goes inside a "list tag", then it should just be the opening tag with a "/" before the closing bracket. The following tables contain all available tags, as well as their purpose and accepted values.

This page is missing information. Do not remove this notice until it is complete.



These tags typically bracket other tags, sometimes the entire file, and are generally used to specify more than one piece of data.

Tag Name Description
TechInfos This begins and ends the file. Everything must go in between these two, or it will not work.
TechInfo Encloses the entry for each technology.


Tag Name Description
Advisor The category of this text, used in-game to provide suggestions of what to research. For example, Religion, Culture, Growth, or Military, among others.
Button A comma separated field that lists four things: the path of the normal tech image, the path of the smaller image for this tech, and then x-y grid coordinates of the smaller image. The path of the normal image must be written.
Civilopedia The text for a tech's civilopedia entry. It may reference a text file if it starts with TXT_KEY_.
Description The in-game label for a tech. It may reference a text file if it starts with TXT_KEY_.
Era The pre-defined era of technologies that this technology belongs to (e.g. Ancient, Classical, Medieval, etc.).
FirstFreeUnitClass Provides the first player to research this technology a unit of the specified unit class.
Help This defines the help tips given for this technology upon mouseover. It may reference a text file if it starts with TXT_KEY_.
Quote The quote displayed in the civilopedia for this tech. It may reference a text file if it starts with TXT_KEY_.
Sound Reference to the sound played when this tech is researched.
SoundMP Reference to the sound played when this tech is researched in a multiplayer game.
Strategy This contains the strategy text for a specific technology. It may reference a text file if it starts with TXT_KEY_.
Type A unique internal label assigned to this tech. This is the first tag for each specific tech.


All of these tags have a numerical value. Though it sometimes can be negative, it usually is not.

Tag Name Description
iAdvancedStartCost Cost to start with tech via Advanced Start. All technologies have a value of 100.
iAdvancedStartCostIncrease Additional cost per tech bought through Advanced Start. All technologies have a value of 0.
iAITradeModifier A percentage value, this is the modifier used by AI leaders in trade negotiations. Some techs, like Fiber Optics, have values at 10.
iAIWeight The base AI point value of this tech, used for AI decision-making.
iAsset The incremental modifier used to increase a player's score.
iCost The default research cost, before modifiers like difficulty level are applied.
iFeatureProductionModifier Optional. A percentage value, it modifies the production output of some worker actions, liking chopping forests.
iFirstFreeTechs The number of free techs for the first leader to research this tech.
iGridX The x-coordinate, or column, to place the technology item in the tech tree.
iGridY The y-coordinate, or row, to place the technology item in the tech tree.
iHappiness Incremental modifier to raise the happiness in each city by the specified value.
iHealth Incremental modifier to raise the health in each city by the specified value.
iPower Incremental modifier to raise the player's power rating, as viewed by the AI, by the specified value.
iTradeRoutes Increases the number of trade routes per city by the specified amount.
iWorkerSpeedModifier A percentage value, this modifies the speed of the player's workers. For example, Steam Power has a value of 50 (meaning a +50% increase).


All of these can either be 1 (on, or true) or 0 (off, or false). Be careful, as you can wind up with a double-negative, which the game will interpret as "True".

Tag Name Description
bBridgeBuilding Enables bridge building, or movement via road over a river without penalty.
bDefensivePactTrading Enables trading of defensive pacts with other civilizations.
bDisable If set as 1, prevents this tech from being researched.
bExtraWaterSeeFrom If true, increases naval units' line of sight by 1 tile.
bGoldTrading Allows gold trading in diplomacy.
bGoodyTech Allows this tech to be received from a goody hut.
bIgnoreIrrigation Allows farms to be built regardless of nearby fresh water.
bIrrigation Allows for "chain irrigation", or irrigation on tiles not directly located next to fresh water.
bMapCentering If true, centers the world map for the player.
bMapTrading Allows for map trading in diplomacy.
bMapVisible Reveals the entire world map, even unresearched parts.
bOpenBordersTrading Allows for open borders trading in diplomacy.
bPermanentAllianceTrading Allows for negotiation of permanent alliances in diplomacy.
bRepeat Allows this technology to be researched multiple times (for example, Future Techs have this set at 1).
bRiverTrade Allows trade routes to form along rivers (Sailing allows this in the standard game).
bTechTrading Allows the player to trade technologies in-game.
bTrade Allows the player to trade this technology in particular in diplomacy.
bVassalTrade Allows the negotiation of vassal agreements, as well as capitulation during war.
bWaterWork Allows the player to assign citizens to work coast or ocean tiles.

Lists (Multi-line)

All List tags consist of an opening/closing tag, which is shown here, and then each entry within it is another tag with the same name as the parent tag, minus the "s" (i.e. singular, rather than plural).

Tag Name Description
AndPreReqs This lists all technologies that must be researched before this technology. In-game, it creates an icon in the top right of the tech's button on the tech tree.
DomainExtraMoves Gives a specified number of movement points to units of a certain type. For example, Refrigeration gives all naval units +1 movement.
CommerceFlexible Allows for the adjustment of the specified commerce slider (science, culture, etc.).
Flavors Modifies AI point weighting based on an assigned flavor (potential flavors include Production, Science, Growth, and Military, among others).
OrPreReqs Used to draw the connecting lines on the tech tree, this lists all of the "OR" prerequisites: that is, you must discover at least one of these technologies before you can research the tech in question.
SpecialBuilding Unknown. This is defined in the schema file, but not listed in the Civ4TechInfos file itself.
TerrainTrades Allows trade across the specified terrain types. For example, Sailing allows trade on coastal tiles.


In the following example of code, please note that there is a specific order of all of the tags. You must list the tags in this order for the game to properly interpret your file.





Audio; Buildings:




Civilizations; Events:
















Italics: Beyond the Sword only