Editing Effects

This page partially describes the contents of a ruleset collection. It is intended as developer reference and for people wanting to create/compile alternative rulesets for Freeciv.
Also check Requirements.
An effect is an integer value (guaranteed supported diapasone is -32768..32767) that is calculated according to the game rules and makes sense to the game in specific situations. The word effect in the code or documentation might mean one of three things: 1) effect type, 2) individual effect and 3) specific effect value. Effect in narrow sense (2) is some value bound to the type (1), some requirement vector and possibly a player multiplier; at some moments that depend on the type, all such effects of this type that have all their requirements evaluated to true are summed and give the effect value (3). All this and its ruleset representation explained below.
==The anatomy of an effects ruleset file==
The effects.ruleset file contains all effects in play in a Freeciv scenario. Typically it contains *include as cheat sheet for AIs.
They have the following form:
[effect_hydro_plant]
name = "Output_Bonus"
value = 25
reqs = {"type", "name", "range"
 "Building", "Factory", "City"
 "Building", "Hydro Plant", "City"
 "OutputType", "Shield", "Local"
 } 
:The text in the brackets is the entry name, which just has to be unique, but is otherwise not used.
:The name field tells Freeciv which Effect Type you are defining. The value is the effect's value, which depends on which effect it is. The reqs table contain a list of requirements for this effect being in effect. You need to satisfy all requirements listed here for this effect to take effect in the game.
:The value field is the integer amount parameter for many effects (must be in the range -32767 to 32767; some do not handle negative numbers well). When an effect of a specific type is tested, all values bound to requirements matching the case are summed up (exceptions are spaceship parts effects).
:The reqs table consists of sets of Requirement Type, Requirement, and Requirement Range.
:Some requirement types may only work at certain ranges. In particular, at present, "Continent" range effects can affect only cities and units in cities.
:2.4 Negation
:There is the nreqs table which is the opposite of the reqs table, these are conditions which prevent the effect from taking place. Any one of the nreq conditions will prevent the effect from taking effect.
nreqs = {"type", "name", "range"
 "Building", "Factory", "City"
 } 
:2.5 Negation
:A requirement may have a negated field, and if this is 'TRUE', the requirement is negated.
reqs = {"type", "name", "range", "negated"
 "Building", "Factory", "City", TRUE
 } 
:2.6 Negation
:The negated field is replaced with present field, defaulting to 'TRUE', but if 'FALSE' requirement must not be fulfilled.
reqs = {"type", "name", "range", "present"
 "Building", "Factory", "City", FALSE
 } 
:Survives
:A requirement may have a survives field, and if this is 'TRUE', the effect survives destruction (mostly used with wonders, see limitations below).
[effect_plastics_slowdown]
type = "Slow_Down_Timeline"
value = 1
reqs =
 { "type", "name", "range", "survives"
 "Tech", "Plastics", "World", TRUE
 }
===Effect Types===
Effect Type 	When affects game 	Factors that may be considered in reqs 	Factors that may be considered in reqs	Factors that may be considered in reqs 	Factors that may be considered in reqs 	Explanation
Effect Type 	When affects game 	Player [/ Other player] 	City 	Tile 	Other 	Explanation
Empire_Size_Mod Removed in version 2.2. 	 	 	 	 	 	Once your civilization has more cities than amount + the server setting 'cityfactor', each city gets one more unhappy citizen.
No_Incite Replaced with the Incite City action in 2.6 	 	 	 	 	 	City cannot be incited.
Revolution_When_Unhappy Replaced with Revolution_Unhappiness in 2.6 	 	 	 	 	 	If a city owned by this player is in revolt for more than two turns, government falls.
Unbribable_Units Replaced with the Bribe Unit action in 2.6 	 	 	 	 	 	Units cannot be bribed.
Airlift 	Phase end 	Each player 	Each player's city 	City center 	 	
Allow airlift to/from a city. Starting from 2.2 amount of units can airlift each turn. 	 	 	 	 	 	
Any_Government 	Any time 	Any player 	 	 	 	
Allow instant government changes. 	 	 	 	 	 	
Capital_City 	Any time 	City owner 	Any city 	City center 	 	
The city with this effect is the capital city. 	 	 	 	 	 	
City_Vision_Radius_Sq 	Virtually any time 	City owner 	City 	City center 	 	
City vision radius in squared distance is increased by amount tiles (base is civstyle.init_vis_radius_sq in game.ruleset) 	 	 	 	 	 	
Civil_War_Chance 	When a capital is taken (maybe destroyed) and there are free player slots 	Loser 	 	 	 	
Base chance in percent of a nation being split by civil war when its capital is captured is increased by this amount. This percentage is increased by 5 for each city in civil disorder and reduced by 5 for each one celebrating (in newer versions, configurable in game.ruleset). 	 	 	 	 	 	
Defend_Bonus 	When a unit defends 	Defending unit owner 	Defended city (if present) 	Target tile 	Attacking unit type 	Increases defensive bonuses of units. Any unit requirements on this effect will be applied to the _attacking_ unit. The defensive bonus is ignored by attackers with "IgWall" flag (up to 2.5). Attackers with "BadWallAttacker" flag will have their firepower set to 1.
Empire_Size_Step 	Whenever a city happiness is updated 	City owner 	 	 	 	
After your civilization reaches Empire_Size_Base size, it gets one more unhappy citizen for each amount of cities it gets above that. Set to zero to disable. You can use Empire_Size_Step even though Empire_Size_Base is zero. 	 	 	 	 	 	
Enable_Nuke 	When production of a unit is changed to or is ready to happen 	City owner 	 	 	 	
Allows the production of nuclear weapons. 	 	 	 	 	 	
Enable_Space 	When production of a spaceship part is changed to or is ready to happen 	City owner 	 	 	 	
Allows the production of space components. 	 	 	 	 	 	
Force_Content 	Whenever the city happiness is updated 	City owner 	Any city 	City tile 	 	
Make amount unhappy citizens content. Applied after martial law and unit penalties. 	 	 	 	 	 	
Gain_AI_Love 	Phase start 	Player 	 	 	 	
Gain amount points of "AI love" with AI(s) per turn. Maximal is 1000. 	 	 	 	 	 	
Give_Imm_Tech 	When a building is finished 	City owner 	City 	 	 	
Building built 	Give amount techs immediately. 	 	 	 	 	
Growth_Food 	Phase end, when processing a city that changes its size, before and after production 	City owner 	City 	City tile 	 	
Food left after cities grow or shrink is amount percent of the capacity of the city's foodbox. This also affects the 'aqueductloss' penalty. Since 3.2 : No longer affects shrinking cities, see Shrink_Food 	 	 	 	 	 	
Fanatics 	Phase end 	Player 	 	 	 	
Units with "Fanatics" flag incur no upkeep. 	 	 	 	 	 	
Happiness_To_Gold 	Phase end 	City owner 	City 	City tile 	 	
Make all Make_Content and Force_Content effects generate also gold in the same amount. 	 	 	 	 	 	
Has_Senate 	When a player tries to break a treaty 	Player 	 	 	 	
Has a senate that prevents declarations of war in most cases. 	 	 	 	 	 	
Have_Embassies 	When a new tech is got known 	Player learned a tech 	 	 	 	
Like having embassies with all the players one has ever had contact with. In 2.6 and prior provided embassy-like effect with all the players (like having both Have_Contacts and Have_Embassies) 	 	 	 	 	 	
HP_Regen 	Phase start 	Unit owner 	Tile city (if present) 	Unit tile 	Unit, unit type 	Units that do not move recover amount percentage of their full hitpoints per turn.
Incite_Cost_Pct 	Whenever one tries to incite a city 	City owner 	City 	City tile 	 	
Increases revolt cost by amount percent. 	 	 	 	 	 	
Inspire_Partisans 	Queried by Lua callbacks, P and C supplied by Lua 	P (former city owner) 	C (a city) 	City tile 	 	
Partisan units (defined in units.ruleset) may spring up. Partially unhardcoded and may be (more) city-dependent since 2.5. 	 	 	 	 	 	
Make_Content 	Whenever the city happiness is updated 	City owner 	City 	City tile 	- 	Make amount unhappy citizens content. Applied before martial law and unit penalties.
Make_Content_Mil 	Whenever the city happiness is updated 	City owner 	City 	City tile 	- 	Make amount unhappy citizens caused by units outside of a city content.
Make_Content_Mil_Per 	Whenever the city happiness is updated 	City owner 	City 	City tile 	- 	Make amount per unit of unhappy citizens caused by units outside of a city content.
Make_Happy 	Whenever the city happiness is updated 	City owner 	City 	City tile 	- 	Make amount citizens happy.
Martial_Law_Each 	Whenever the city happiness is updated 	City owner 	City 	City tile 	- 	The amount of citizens pacified by each military unit giving martial law.
Martial_Law_Max 	Whenever the city happiness is updated 	City owner 	City 	City tile 	- 	The maximum amount of units that will give martial law in city. Zero value means no limit.
Max_Rates 	When one tries to change taxes 	Player 	 	 	 	
The maximum setting for each tax rate is amount. 	 	 	 	 	 	
Move_Bonus 	A lot (phase start, combat, transforming a unit...) 	Unit owner 	City on the tile (if present) 	Unit tile 	Unit type 	Add amount movement to units. Use UnitClass' requirement with range of 'Local' to give it a specific class of units only.
No_Anarchy 	When a player tries to break a treaty 	Player 	 	 	 	
No period of anarchy between government changes. (This also neuters the Has_Senate effect.) 	 	 	 	 	 	
No_Diplomacy 	Players make contact, split by CW or try to meet 	Player 	 	 	 	
Cannot use any diplomacy. 	 	 	 	 	 	
No_Sink_Deep Removed in version 2.2. 	 	 	 	 	 	Triremes no longer sink when on dangerous seas.
No_Unhappy 	Whenever the city happiness is updated 	City owner 	City 	City tile 	 	
No citizens in the city are ever unhappy. 	 	 	 	 	 	
Nuke_Proof 	When a nuclear unit tries to explode near the city 	City owner 	City 	Targeted tile 	 	
City is nuke proof. Since 2.6, specifies the percentage chance of deflecting a nuke. 	 	 	 	 	 	
Output_Bonus 	Phase end, in city processing order 	City owner 	Any city 	- 	Output type 	City production is increased by amount percent.
Output_Bonus_2 	Phase end, in city processing order 	City owner 	Any city 	- 	Output type 	City production is increased by amount percent after Output_Bonus, so is multiplicative with it.
Output_Add_Tile 	Phase end, in city processing order 	City owner 	Any city 	Each worked tile 	Output type 	Add amount to each worked tile.
Output_Inc_Tile 	Phase end, in city processing order 	City owner 	Any city 	Each worked tile 	Output type 	Add amount to each worked tile that already has at least 1 output.
Output_Inc_Tile_Celebrate 	Phase end, in city processing order 	City owner 	Any city 	Each worked tile 	Output type 	Tiles get amount extra output when city working them is celebrating.
Output_Penalty_Tile 	Phase end, in city processing order 	City owner 	Any city 	Each worked tile 	Output type 	When a tile yields more output than amount, it gets a penalty of -1, unless the city is celebrating.
Output_Per_Tile 	Phase end, in city processing order 	City owner 	Any city 	Each worked tile 	Output type 	Increase tile output by amount percent.
Output_Waste 	Phase end 	City owner 	Each city 	- 	Output type 	Base amount in percentage that each city has in waste. Waste can be used with any output type, use an OutputType requirement to specify which.
Output_Waste_By_Distance 	Phase end 	City owner 	Each city 	- 	Output type 	For each tile in real distance that a city is from nearest government center, it gets amount of extra waste.
Output_Waste_Pct 	Phase end 	City owner 	Each city 	- 	Output type 	Reduce waste by amount percent.
Pollu_Pop_Pct 	Phase end 	City owner 	Each city 	- 	- 	Increases pollution caused by each unit of population by amount percent (adds to baseline of 100%, i.e. 1 pollution per citizen).
Pollu_Prod_Pct 	Phase end 	City owner 	Each city 	- 	- 	Increases pollution caused by shields by amount percent.
Rapture_Grow 	Phase end 	City owner 	City 	City tile 	 	
Can rapture grow cities. 	 	 	 	 	 	
Reveal_Cities 	Phase end, after all players are processed 	Player 	- 	- 	- 	Immediately make all cities known (with their tiles).
Reveal_Map 	Phase end, after all players are processed 	Player 	- 	- 	- 	Immediately make entire map known.
Size_Adj 	Whenever a city tries to grow by food, adding etc. 	City owner 	City 	City tile 	- 	Increase maximum size of a city by amount.
Size_Unlimit 	Whenever a city tries to grow by food, adding etc. 	City owner 	City 	City tile 	- 	Make the size of a city unlimited.
Slow_Down_Timeline 	Between turn end and next turn start 	 	 	 	 	
Slow down the timeline based on the AMOUNT. If AMOUNT >= 3 the timeline will be max 1 year/turn; with AMOUNT == 2 it is max 2 years/turn; with AMOUNT == 1 it is max 5 years/turn; with AMOUNT <= 0 the timeline is unaffected. The effect will be ignored if game.spacerace isn't set. 	 	 	 	 	 	
Specialist_Output 	Phase end 	City owner 	Any city 	 	 	
Specialist type, output type 	Specify what outputs a specialist is producing. Should be used with an OutputType requirement. 	 	 	 	 	
Spy_Resistant 	Whenever a diplomatic attack is performed on a tile with a diplomatic defender 	Owner of the targeted tile (if present) 	City on the tile (if present) 	Targeted tile 	 	
If a spy specifies a target for sabotage, then she has an AMOUNT percent chance to fail. Also in diplomatic combat defending diplomatic units in cities will get an AMOUNT percent bonus. All Spy_Resistant's are summed before being applied. 	 	 	 	 	 	
SS_Structural,SS_Component,SS_Module 	When switching to or producing a building 	 	 	 	 	
Only a "Building" requirement with any range turns these effects on 	A part of a spaceship; this is a "Local" ranged effect. It (for now) applies to improvements which cannot be built unless "Enable_Space" is felt. Buildings which have this effect should probably not be given any other effects.	 	 	 	 	
Tech_Parasite 	Phase end, before processing cities 	Each player 	 	 	 	
Gain any advance known already by amount number of other teams or players (if research is not shared between team members). Note that if you have two such effects, they combine into one much worse effect (the number of players required to gain an advance is increased). 	 	 	 	 	 	
Trade_Revenue_Bonus 	When a caravan arrives into a city 	Owner of caravan's home city / Owner of target city 	Home city 	Home city tile 	Since 2.6: caravan action ("Establish Trade Route"/"Enter Marketplace")Since 3.2: Actor unit type 	Trade revenue is multiplied by pow(2, amount/1000). The amount value is taken from the caravan's home city.
Unhappy_Factor 	Whenever a city's happiness is updated 	City owner 	 	 	 	
Multiply unhappy unit upkeep by amount. 	 	 	 	 	 	
Unit_No_Lose_Pop 	When a city is attacked or bombarded 	City owner 	City 	City tile 	 	
No population lost when a city's defender is lost. 	 	 	 	 	 	
Unit_Recover 	Phase start 	Unit owner 	City on the tile (if present) 	Unit tile 	Unit, unit type 	Units recover amount extra hitpoints per turn.
Unit_Upkeep_Free_Per_City 	Phase end 	City owner 	City 	 	 	
Output type 	In each city unit upkeep is deducted by this amount. As usual, you can use with OutputType requirement to specify which kind of upkeep this should be. 	 	 	 	 	
Unit_Vision_Radius_Sq 	Virtually any time 	Unit owner 	Tile city (if present) 	Unit tile 	Unit type, Since 3.2: Individual unit 	Increase unit vision radius in squared distance by amount tiles. The initial value is set by the "vision_radius_sq = X" in the unit's definition.
Upgrade_Unit 	Phase start, before restoring hp/mp 	Player 	 	 	 	
Upgrade amount obsolete units per turn. 	 	 	 	 	 	
Upkeep_Free 	Phase end 	City owner 	Each city 	 	 	
Each building in the city 	Improvements with amount or less upkeep cost become free to upkeep (others are unaffected). 	 	 	 	 	
Upkeep_Factor 	Phase end 	Player 	 	 	 	
Output type, Since 3.2: Unit type 	Multiply unit upkeep by amount. 	 	 	 	 	
Veteran_Build 	When a unit is produced (even consuming last pop from a city) 	City owner 	City 	City tile 	Unit type 	New units of this type start with veterancy. In 2.4 and prior, the amount value is ignored, so that you can have multiple Veteran_Build effects, and units will only get 1 free veterancy level. In 2.5 and later, amount specifies the initial veteran level and is cumulative.
Veteran_Combat 	When a unit may become a combat veteran 	Unit owner 	Tile city (if present) 	Unit tile 	Unit, unit type 	Increases the chance of units of this type becoming veteran after combat by amount percent.
Effect type 	New in 2.1 	New in 2.1 	New in 2.1 	New in 2.1 	New in 2.1 	Explanation
Effect type 	When affects game 	Player [ / Other player] 	City 	Tile 	Other factors 	Explanation
Visible_Walls 	When a city packet is sent to a client (no game value). 	City owner 	City 	City tile 	 	
Positive amount only instructs clients to use wall graphics for city.
 New in 2.6: Exact amount tells wall set to draw 	 	 	 	 	 	
Effect type 	New in 2.2 	New in 2.2 	New in 2.2 	New in 2.2 	New in 2.2 	Explanation
Effect type 	When affects game 	Player [ / Other player] 	City 	Tile 	Other factors 	Explanation
City_Unhappy_Size 	Whenever a city happiness is updated 	City owner 	- 	- 	- 	Each citizen after amount of citizens are unhappy instead of content.
Empire_Size_Base 	Whenever a city happiness is updated 	City owner 	- 	- 	- 	Once your civilization has more cities than the value of this effect, each city gets one more unhappy citizen. If the sum of this effect and Empire_Size_Step is zero, there is no such penalty.
Health_Pct 	Phase end, when illness may strike a city 	City owner 	City 	City tile 	 	
Reduces probaility of illness (plague) in a city by amount percent. This has no effect in rulesets which do not have plague enabled. 	 	 	 	 	 	
Migration_Pct 	Turn end 	City owner 	City 	City center 	 	
Increase the calculated migration score for the a city by amount in percent. 	 	 	 	 	 	
Shield2Gold_Factor 	Phase end 	Player 	 	 	 	
Factor in percent for the conversion of unit shield upkeep to gold upkeep. A value of 200 would transfor 1 shield upkeep to 2 gold upkeep. The range of this effect must be player or world. Note that only units with the "Shield2Gold" flag will be affected by this. 	 	 	 	 	 	
Tech_Cost_Factor 	Phase end 	Player 	 	 	 	
Multiplier for research cost. 	 	 	 	 	 	
Tile_Workable 	A lot (units move, city size or radius change...) 	City owner 	City 	Tile 	 	
If value != 0, city can work target tile. 	 	 	 	 	 	
Turn_Years 	Between turn end and next turn start 	 	 	 	 	
Calendar advances amount years each turn unless Slow_Down_Timeline effects override this. 	 	 	 	 	 	
Upgrade_Price_Pct 	Player orders to upgrade a unit 	Player 	 	 	 	
Increases unit upgrade cost by amount percent. This effect works at player level. You cannot adjust upgrade costs for certain unit type or for units upgraded in certain city. 	 	 	 	 	 	
Effect type 	New in 2.3 	New in 2.3 	New in 2.3 	New in 2.3 	New in 2.3 	Explanation
Effect type 	When affects game 	Player [ / Other player] 	City 	Tile 	Other factors 	Explanation
City_Build_Slots 	When a unit is produced 	City owner 	City 	City tile 	 	
Increase the number of units with no population cost a city can build in a turn by amount. The required shields must be available. 	 	 	 	 	 	
City_Radius_Sq 	On virtually any city change 	City owner 	City 	City tile 	 	
Increase the squared city radius by amount. The initial value is set by the "init_city_radius_sq = X" in game.ruleset.
(In old versions could only usefully have "MinSize", "Building", or "Tech" requirements) 	 	 	 	 	 	
Tech_Upkeep_Free 	Phase end, after processing all cities of all players 	Each player 	 	 	 	
If this value is greater than 0, the tech upkeep is reduced by this value. For tech upkeep style Basic this is total reduction, for tech upkeep style Cities (new in 2.6) this is applied to every city. 	 	 	 	 	 	
Effect type 	New in 2.4 	New in 2.4 	New in 2.4 	New in 2.4 	New in 2.4 	Explanation
Effect type 	When affects game 	Player [ / Other player] 	City 	Tile 	Other factors 	Explanation
City_Image 	No game value. Sent by server, if not (-100), deduced by client. 	City owner 	City 	City tile 	 	
The index for the city image of the given city style. Allows to align the city image with the city radii. 	 	 	 	 	 	
Irrig_Possible Replaced with action enabler in version 3.1 	When a unit tries to apply the activity 	Unit owner 	Tile city (if present) 	Tile 	Unit, unit type 	If value of this effect > 0, target tile can be irrigated. In addition to requirements of this effect, there's still hardcoded requirement that unit doing the irrigation has "Settlers" flag, and terrain.ruleset controls which terrain types can be irrigated at all.
Effect type 	New in 2.5 	New in 2.5 	New in 2.5 	New in 2.5 	New in 2.5 	Explanation
Effect type 	When affects game 	Player [ / Other player] 	City 	Tile 	Other factors 	Explanation
Enemy_Citizen_Unhappy_Pct 	Whenever city happiness is updated 	City owner 	City 	City tile 	 	
During war, citizens of enemy nationality are more unhappy. Value of this effect tells how many percents of the enemy citizens in cities get unhappy because of the war. 	 	 	 	 	 	
Gov_Center 	When this or any dependent (not having closer GC's) city output is calculated 	City owner 	City 	City tile 	 	
City with non-zero effect value is considered Governmental center. Unless corruption is flat for entire nation, it depends on distance to nearest such center. In earlier versions this effect was coupled in to Capital_City effect. 	 	 	 	 	 	
Irrig_TF_Possible Replaced with action enabler in version 3.1 	When unit tries to start the activity 	Unit owner 	Tile city (if present) 	Tile 	Unit, unit type 	If value of this effect > 0, tile terrain can be changed by irrigating action. In addition to requirements of this effect, terrain.ruleset controls which terrain types can be transformed this way.
Max_Trade_Routes 	When a caravan tries to establish a trade routeAfter a city changes hands 	City owner 	Dest. city 	City tile 	 	
Value of this effect tells how many trade routes city can establish. It affects only attempts to establish new routes, existing routes are not removed if value gets smaller than current number of routes (but only as long as the city does not change hands). Maximum value, to which this value is clipped itself, is 5 routes.	 	 	 	 	 	
Mining_Possible Replaced with action enabler in version 3.1 	When unit tries to start the activity 	Unit owner 	Tile city (if present) 	Tile 	Unit, unit type 	If value of this effect > 0, mine can be built to target tile. In addition to requirements of this effect, terrain.ruleset controls which terrain types can have mines at all.
Mining_TF_Possible Replaced with action enabler in version 3.1 	When unit tries to start the activity 	Unit owner 	Tile city (if present) 	Tile 	Unit, unit type 	If value of this effect > 0, tile terrain can be changed by mining action. In addition to requirements of this effect, terrain.ruleset controls which terrain types can be transformed this way.
Not_Tech_Source 	When one tries to steal a tech from the player 	Player 	 	 	 	
Tech cannot be received from this player by any means. 	 	 	 	 	 	
Transform_Possible Replaced with action enabler in version 3.1 	When unit tries to start the activity 	Unit owner 	Tile city (if present) 	Tile 	Unit, unit type 	If value of this effect > 0, target tile can be transformed. In addition to requirements of this effect, terrain.ruleset controls which terrain types can be transformed at all.
Effect type 	New in 2.6 	New in 2.6 	New in 2.6 	New in 2.6 	New in 2.6 	Explanation
Effect type 	When affects game 	Player [ / Other player] 	City 	Tile 	Other factors 	Explanation
History 	Phase end, just after the stage production may happen 	City owner 	City 	City center 	 	
Value of this effect is how much cumulative History-type culture the city is producing. 	 	 	 	 	 	
Illegal_Action_Move_Cost 	An action with illegal trial punishment is attempted 	Unit owner / Target player 	- 	- 	Actor unit, unit type, action 	Unit attempted the action loses this number of move fragments (all if has less).
Irrigation_Pct 	Phase end, for each city of each player 	City owner 	City 	Workable tile with extra in question and nonzero output bonus from it	- 	This effect controls how much of the terrain specific irrigation bonus applies.
Mining_Pct 	Phase end, for each city of each player 	City owner 	City 	Workable tile with extra in question and nonzero output bonus from it	- 	This effect controls how much of the terrain specific mining bonus applies.
National_History 	Phase end, just after cities are processed 	Player 	 	 	 	
Value of this effect is how much cumulative History-type culture the city is producing in addition to that produced by individual cities. 	 	 	 	 	 	
National_Performance 	When score is calculated, by Lua callbacks, to test "MinCulture" reqs, for achievments 	Player 	 	 	 	
Value of this effect is how much Performance-type culture the nation is producing in addition to that produced by individual cities. 	 	 	 	 	 	
Output_Tile_Punish_Pct 	Phase end, in city processing order 	City owner 	Any city 	Each worked tile 	Output type 	Reduce the output of a tile by amount percent. The number of units to remove is rounded down. Applied after everything except a city center's minimal output.
Performance 	When migration is considered, by Lua callbacks, to test "MinCulture" reqs, for achievments 	City owner 	City 	City center 	 	
Value of this effect is how much Performance-type culture the city is producing. Performance is not persistent culture, but affects only
current turn. 	 	 	 	 	 	
Pollu_Pop_Pct2 	Phase end, in city processing order 	City owner 	Any city 	City center 	 	
Multiplicative effect with Pollu_Pop_Pct (i.e., if both 25, result is 125x125/100=156) 	 	 	 	 	 	
Retire_Pct 	Turn start 	Unit owner 	Tile city (if present) 	Unit tile 	Unit, unit type 	If there are no enemy units or cities in 3 tiles range (7x7 square), removes the unit with this probability (used for barbarians).
Revolution_Unhappiness 	Phase end, after production and city-based upkeep 	City owner 	City 	City center 	 	
If a city is in revolt for more than value turns, government falls. (Note: it's a city-based effect but AI/advisors rely on it being player-based) 	 	 	 	 	 	
Traderoute_Pct 	When city trade production is calculated 	City owner 	City 	City center 	 	
Percentage bonus for trade from traderoutes. This bonus applies after the value of the traderoute is already calculated. It affects one end of the traderoute only. 	 	 	 	 	 	
Turn_Fragments 	Between turn end and next turn start 	 	 	 	 	
Calendar advances amount fragments each turn, in addition to years advanced by Turn_Years. 	 	 	 	 	 	
Unit_Bribe_Cost_Pct 	When one tries to bribe a unit 	Target unit owner / Bribing player 	Target unit home city 	Unit tile 	Target unit, unit type 	Increases unit bribe cost by amount percent.
Victory 	Between turns 	Each player (order is default but all the qualified win together) 	 	 	 	
When value of this effect gets positive, player wins the game. In simplest case you'll have just one such effect with value 1 (or any positive value) and thus requirements of that effect are requirements for winning the game. 	 	 	 	 	 	
Effect type 	New in 3.0 	New in 3.0 	New in 3.0 	New in 3.0 	New in 3.0 	Explanation
Effect type 	When affects game 	Player [ / Other player] 	City 	Tile 	Other factors 	Explanation
Action_Odds_Pct 	Almost any possible action (not attack in 3.0) 	Actor player / Target player 	Target city 	- 	Actor unit, unit type, action 	Odds of an action (100%, diplchance or 0% basically) are set to
\mathrm{odds}+\frac{\mathrm{odds}\times\mathrm{value}}{100}.
Attack_Bonus 	A unit attacks 	Attacker owner 	Defended city (if present) 	Target tile 	Attacking unit type, 'Since 3.2: unit instance 	Increases offensive bonuses of units.
Border_Vision 	Phase very end 	Player 	- 	 	 	
- 	If borders are on, grants to the player vision of everything inside his or her borders. 	 	 	 	 	
Building_Buy_Cost_Pct 	When one buys a building 	City owner 	City 	 	 	
Building type 	Increases building buy cost by AMOUNT percent. 	 	 	 	 	
Building_Saboteur_Resistant 	When a hostile unit sabotages an improvement in the city 	City owner 	Target city 	City center 	 	
"Spy_Resistant" split for sabotaging a building: the building's "sabotage" property is multiplied on AMOUNT percents. 	 	 	 	 	 	
Casus_Belli_Caught 	When a unit is caught at a hostile diplomatic action 	Unit owner / Victim player 	Target tile city (if present) 	Target tile 	Actor unit, unit type, action 	Diplomatic consequence of an action when the ill-doer is caught before performing it. Value >= 1 gives casus belli to the victim, >= 1000 to everybody.
Casus_Belli_Success 	When a unit succeeds in a hostile action 	Unit owner / Victim player 	Target tile city (if present) 	Target tile 	Actor unit, unit type, action 	Diplomatic consequence of an action when the unit does its dark business (may perish escaping afterwards). Value >= 1 gives casus belli to the victim, >= 1000 to everybody.
Combat_Rounds 	When a unit attacks 	Unit owner 	Tile city (if present) 	Unit tile 	Attacker unit, unit type 	Maximum number of rounds combat lasts. Zero or negative value means that combat is always to death.
Conquest_Tech_Pct 	A unit has just entered a conquered city (has not yet even risen the new flag!) 	Unit owner 	Conquered city 	Unit/city tile 	Unit, unit type 	When a city is conquered, conqueror has a AMOUNT percentage chance to get a tech from the player losing the city.
Have_Contacts 	The very end of the phase 	Player 	 	 	 	
Provides contact with all the other players. 	 	 	 	 	 	
Output_Waste_By_Rel_Distance 	Phase end 	City owner 	Each city 	- 	Output type 	Works like Output_Waste_By_Distance (additively to it) if the world map's bigger dimension is 50. Otherwise, the waste is scaled relatively to the world's size.
Stealings_Ignore 	When a unit steals a tech from a city 	Unit owner 	Unit tile city (if present) 	Unit tile 	Actor unit, unit type 	When determining how difficult it is to steal a tech from enemy, AMOUNT
previous times tech has been stolen from the city is ignored. For spies that can possibly escape, the difficulcy of the operation grows exponentially with each unignored stealth; diplomats that can't escape just fail outside of this amount.
Unit_Buy_Cost_Pct 	When one buys a unit 	City owner 	City 	City tile 	Unit type 	Increases unit buy cost by AMOUNT percent.
Effect type 	New in 3.1 	New in 3.1 	New in 3.1 	New in 3.1 	New in 3.1 	Explanation
Effect type 	When affects game 	Player [ / Other player] 	City 	Tile 	Other factors 	Explanation
Action_Success_Actor_Move_Cost 	An action is performed (right after "action started..." callback) 	Actor player 	Tile city (if present) 	Unit tile 	Actor unit, unit type, action 	Unit loses this number of move fragments (all if has less) for this action. Use "MinMoveFrags" requirement in the action enabler to disable acting on lower mp.
Action_Success_Target_Move_Cost 	A unit-on-unit action is performed (right after Lua callback) 	Target unit owner 	Tile city (if present) 	Unit tile 	Target unit, unit type, action 	Unit loses this number of move fragments (all if has less) for being a target of this action.
Building_Build_Cost_Pct 	Any time 	City owner 	City 	 	 	
Building type 	Increases building cost of a building. 	 	 	 	 	
Fortify_Defense_Bonus 	Any time 	Defending unit's owner 	City in defending unit's tile 	Defending unit's tile 	Defending unit 	Gives percentage defense bonus, multiplicative with Defend_Bonus effect
Infra_Points 	Phase end, per city, after the population is updated 	City owner 	City 	City tile 	 	
How many infra points a city produces each turn. 	 	 	 	 	 	
Max_Stolen_Gold_Pm 	At "Steal Gold" action 	Target player 	Target city 	Target city center 	 	
Part of target player's treasury a thief may steal from the city at maximal luck, 1000 means all gold 	At "Steal Gold" action 	 	 	 	 	
Thiefs_Share_Pm 	Unit owner 	Unit tile city (if present) 	Unit tile 	Actor unit, unit type 	How much of the stolen gold the thief spends on herself, 1000 means all. Calculated before the thief tries to escape.	
Unit_Build_Cost_Pct 	Any time 	City owner 	City 	City tile 	Unit type 	Increases building cost of a unit.
Min_HP_Pct 	Turn change 	Unit owner 	City on unit tile 	Unit tile 	Unit, unit type 	Minimum percentage of full health (rounded down) a unit gets resting, applied instead of HP_Regen effect if the latter gives less hitpoints
HP_Regen_2 	Turn change 	Unit owner 	City on unit tile 	Unit tile 	Unit, unit type 	Like HP_Regen, except that gets applied after (and top of) HP_Regen / Min_HP_Pct, and in the calculation unit's full HP is rounded up to nearest ten.
User_Effect_1User_Effect_2User_Effect_3User_Effect_4 	Script defined 	Script defined [a player or city owner] 	Script defined [a city] 	Script defined [city tile] 	 	
User-defined effects, have no predefined meaning but may be evaluated by effects.*_bonus(...) functions in Lua callbacks as any other ones. 	 	 	 	 	 	
Effect type 	New in 3.2 	New in 3.2 	New in 3.2 	New in 3.2 	New in 3.2 	Explanation
Effect type 	When affects game 	Player [ / Other player] 	City 	Tile 	Other factors 	Explanation
Border_Strength_Pct 	Turn change 	Source city or tile owner 	City (source) 	Border source tile 	 	
Adjust strength of the Border Source, either a city or an extra (such as Fortress). Extra's basic strength is 1, city's one is size + 2, percentage is rounded down. 	 	 	 	 	 	
Tech_Parasite_Pct_Max 	Phase end, before processing cities 	Each player 	 	 	 	
Gain any advance known already by amount percent of other alive teams or players (if research is not shared between team members). Note that if you have two such effects, they combine into worse effect (the number of players required to gain an advance is increased). 	 	 	 	 	 	
Shrink_Food 	Phase end, when processing a city that shrinks, before and after production 	City owner 	City 	City tile 	 	
Food left after cities shrink is amount percent of the capacity of the city's foodbox. 	 	 	 	 	 	
Activity_Time 	Phase end, when checking if an activity has completed 	Unit owner 	 	 	 	
Unit tile 	Unit, Activity target extra 	If amount is above zero, it's used as override to activity time calculated by normal rules.	 	 	 	
Surplus_Waste_Pct 	Phase end 	City owner 	Each city 	 	 	
Output type 	Additional amount of waste, applying only to what otherwise would be surplus of the output. If there's no surplus, this does nothing. Waste can be used with any output type, use an OutputType requirement to specify which. 	 	 	 	 	
Surplus_Waste_Pct_By_Rel_Distance 	Phase end 	City owner 	Each city 	 	 	
Output type 	Like Surplus_Waste_Pct, but affected by distance, scaled relative to the map size, to nearest government center. Government center itself does not suffer this kind of waste. 	 	 	 	 	
Impr_Upkeep_Reduction 	Turn change 	City owner 	Each city 	 	 	
Reduce total improvement upkeep the city pays by amount. 	 	 	 	 	 	
Effect type 	New in 3.3 	New in 3.3 	New in 3.3 	New in 3.3 	New in 3.3 	Explanation
Effect type 	When affects game 	Player [ / Other player] 	City 	Tile 	Other factors 	Explanation
Tech_Leakage 	Turn change 	Each player 	 	 	 	
If value is above zero, tech leakage towards the player is enabled. 	 	 	 	 	 	
Culture_Pct 	Simultaneously with Performance / History effects 	Each player, city owner 	Each city 	 	 	
Multiplicative with the History and Performance effects. 	 	 	 	 	 	
== Multipliers ==
New v.2.6 effect syntax element is multiplier parameter that says which multiplier should scale the specified effect value if the reqs are active. Multipliers may be defined by a ruleset to be set by a player; changing a multiplier from its defalt value may have additional requirements, and any player's setting takes an effect only at the beginning of phase ending procedure. Example of a multiplier definition you can find in the governments.ruleset file of Experimental ruleset.
As for v.3.1, a multiplier can be defined in governments.ruleset in a section [multiplier_*] (where * is a name just to be unique). Parameters:
;name:Translatable and visible name of the multiplier.
;rule_name:Optionally, name inside the ruleset files.
;start:Effective minimal value of the multiplier.
;stop:Effective maximal value of the multiplier.
;step:A step that the multiplier is allowed to be shifted within its limits. Intervals between start, stop and default must include integer numbers of steps.
;default:Effective value of the multiplier at game start, or when player loses control over it.
;reqs:Requirement vector. Alive player is in control of the multiplier if all of the requirements are TRUE.
;offset:Visible value offset relative to effective value (default: 0)
;factor:Visible value scale relative to effective value in percents (default: 100)
;minimum_turns:Minimal number of turns allowed between changes of this multiplier.
;helptext:String vector for the help system.
You can define up to 15 multipliers.
 effective_value = (visible_value + offset) * (factor/100)
== See also ==
Category:Editing rulesets