Effects

The effects.ruleset file contains all effects in play in a Freeciv21 ruleset. They have the following form (this is perhaps the most complicated example we could find):

[effect_hydro_plant]
type  = "Output_Bonus"
value = 25
reqs  =
    { "type", "name", "range", "present", "quiet"
      "Building", "Factory", "City", TRUE, FALSE
      "Building", "Hydro Plant", "City", TRUE, FALSE
      "OutputType", "Shield", "Local", TRUE, TRUE
      "Building", "Hoover Dam", "Player", FALSE, FALSE
      "Building", "Nuclear Plant", "City", FALSE, FALSE
    }

The text in the brackets is the entry name, which just has to be unique, but is otherwise not used. The type field tells Freeciv21 which effect 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. Requirements with present = TRUE must be present, those with present = FALSE must not be present.

Value is integral b parameter for many effects (must be in the range -32767 to 32767).

Requirement range may be one of: None, Local, CAdjacent (Cardinally Adjacent), Adjacent, City, Continent, Player, Allied, World. Some requirement types may only work at certain ranges. This is described below. In particular, at present, Continent effects can affect only cities and units in cities.

A requirement may have a survives field, and if this TRUE, the effect survives destruction. This is supported for only a few conditions and ranges: wonders (at world or player range), nations, and advances (both at world range only).

A requirement may have a present field, and if this is FALSE, the requirement is negated (the condition must not be true for the req to be met).

A requirement may have a quiet field, and if this is TRUE, the help system does not try to autogenerate text about that requirement. This can be used if the help system’s text is unclear or misleading, or if you want to describe the requirement in your own words. The quiet field has no effect on the game rules.

Requirement types and supported ranges

Table 4 Effect Flags
Requirement	Supported ranges
`Tech`	`World`, `Alliance`, `Team`, `Player`
`TechFlag`	`World`, `Alliance`, `Team`, `Player`
`MinTechs`	`World`, `Player`
`Achievement`	`World`, `Alliance`, `Team`, `Player`
`Gov`	`Player`
`Building`	`World`, `Alliance`, `Team`, `Player`, `Continent`, `Traderoute`, `City`, `Local`
`BuildingGenus`	`Local`
`Extra`	`Local`, `Adjacent`, `CAdjacent`, `Traderoute`, `City`
`BaseFlag`	`Local`, `Adjacent`, `CAdjacent`, `Traderoute`, `City`
`RoadFlag`	`Local`, `Adjacent`, `CAdjacent`, `Traderoute`, `City`
`ExtraFlag`	`Local`, `Adjacent`, `CAdjacent`, `Traderoute`, `City`
`Terrain`	`Local`, `Adjacent`, `CAdjacent`, `Traderoute`, `City`
`Good`	`City`
`UnitType`	`Local`
`UnitFlag`	`Local`
`UnitClass`	`Local`
`UnitClassFlag`	`Local`
`Nation`	`World`, `Alliance`, `Team`, `Player`
`NationGroup`	`World`, `Alliance`, `Team`, `Player`
`Nationality`	`Traderoute`, `City`
`DiplRel`	`World`, `Alliance`, `Team`, `Player`, `Local`
`Action`	`Local`
`OutputType`	`Local`
`Specialist`	`Local`
`MinYear`	`World`
`MinCalFrag`	`World`
`Topology`	`World`
`ServerSetting`	`World`
`Age` (of unit)	`Local`
`Age` (of city)	`City`
`Age` (of player)	`Player`
`MinSize`	`Traderoute`, `City`
`MinCulture`	`World`, `Alliance`, `Team`, `Player`, `Traderoute`, `City`
`MinForeignPct`	`Traderoute`, `City`
`AI`	`Player`
`MaxUnitsOnTile`	`Local`, `Adjacent`, `CAdjacent`
`TerrainClass`	`Local`, `Adjacent`, `CAdjacent`, `Traderoute`, `City`
`TerrainFlag`	`Local`, `Adjacent`, `CAdjacent`, `Traderoute`, `City`
`TerrainAlter`	`Local`
`CityTile`	`Local`, `Adjacent`, `CAdjacent`
`CityStatus`	`Traderoute`, `City`
`Style`	`Player`
`UnitState`	`Local`
`Activity`	`Local`
`MinMoveFrags`	`Local`
`MinVeteran`	`Local`
`MinHitPoints`	`Local`
`VisionLayer`	`Local`
`NationalIntelligence`	`Local`

MinSize is the minimum size of a city required.
AI is the AI player difficulty level.
TerrainClass is either “Land” or “Oceanic”.
CityTile is either “Center” (city center) or “Claimed” (owned).
CityStatus is “OwnedByOriginal”.
DiplRel is a diplomatic relationship as shown in nations view.
MaxUnitsOnTile is about the number of units present on a tile.
UnitState is “Transported”, “Transporting”, “OnNativeTile”, “OnLivableTile”, “InNativeExtra”, “OnDomesticTile”, “MovedThisTurn”, or “HasHomeCity”.
Activity is “Idle”, “Pollution”, “Mine”, “Irrigate”, “Fortified”, “Fortress”, “Sentry”, “Pillage”, “Goto”, “Explore”, “Transform”, “Fortifying”, “Fallout”, “Base”, “Road”, “Convert”, “Cultivate”, or “Plant”.
MinMoveFrags is the minimum move fragments (MP) the unit must have left.
MinCalFrag is the minimum sub-year division the calendar must have reached, if enabled (see [calendar].fragments in game.ruleset).
Nationality is fulfilled by any citizens of the given nationality present in the city.
ServerSetting is if a Boolean server setting is enabled. The setting must be visible to all players and affect the game rules.

Details about requirement types

The “DiplRel” requirement type

Look for the diplomatic relationship “Never met”, “War”, “Cease-fire”, “Armistice”, “Peace”, “Alliance”, “Team”, “Gives shared vision”, “Receives shared vision”, “Hosts embassy”, “Has embassy”, “Hosts real embassy” (not from an effect), “Has real embassy”, “Has Casus Belli” (reason for war), “Provided Casus Belli” or “Is foreign”.

A DiplRel is considered fulfilled for the range:

“world” if some player in the world has the specified diplomatic relationship to some other living player.
“player” if the player has the specified diplomatic relationship to some other living player.
“local” if the first player has the specified relationship to the second player. Example: When testing a build requirement for an extra the first player is the owner of the unit and the second player the owner of the terrain the extra is built on.

Only the exact relationship required fulfills it. Example: An “Alliance” or an “Armistice” agreement will not fulfill a “Peace” requirement.

It is possible to create a requirement that in some situations will not have a player to check. In those cases the requirement will always be considered unfulfilled. This applies to both present and not present requirements. The ranges “Alliance”, “Team”, “Player” and “Local” needs a player. The Local range also needs the player the first player’s relationship is to.

Example: The requirements below are about the relationship to the owner of a tile. The table shows in what situations a requirement is fulfilled.

Table 5 DiplRel Example
Requirement	Fulfilled when the tile is
Requirement	Domestic	Unclaimed	Foreign
`"DiplRel", "Is foreign", "Local", TRUE`	no	no	yes
`"DiplRel", "Is foreign", "Local", FALSE`	yes	no	no

The “MaxUnitsOnTile” requirement type

Check the number of units present on a tile. Is TRUE if no more than the specified number of units are present on a single tile.

Tip

By using negation (“not present”) it is possible to check if a tile has more than the given numbers. It is possible to combine a negated and a non negated requirement to specify a range.

The “UnitState” requirement type

Transported: is fulfilled if the unit is transported by another unit.
Transporting: is fulfilled if the unit is transporting another unit.
OnNativeTile: is fulfilled if the unit is on a tile with native terrain or with a native Extra. Does not care about details like cities and safe tiles.
OnLivableTile: is fulfilled if the unit is on a tile where it can exist outside of a transport.
InNativeExtra: is fulfilled if the unit is on a tile with an extra native to it.
OnDomesticTile: is fulfilled if the unit is on a tile owned by its player.
MovedThisTurn: is fulfilled if the unit has moved this turn.
HasHomeCity: is fulfilled if the unit has a home city.

The “NationalIntelligence” requirement type

This is only used with the Nation_Intelligence effect.

Effect types

Tech_Parasite: Gain any advance known already by AMOUNT number of other teams, if team_pooled_research is enabled, or AMOUNT number of other players otherwise.

Note

If you have two such effects, they add up (the number of players required to gain an advance is increased).

Airlift: Allow airlift to/from a city. The value tells how many units per turn can be airlifted, unless server setting airlifttingstyle sets the number unlimited for either source or destination city. If airlifts are set to unlimited, they are enabled by any positive value of this effect.

Any_Government: Allow changing to any form of government regardless of tech prerequisites.

Capital_City: The city with a positive value is a capital city. Player’s city with highest Capital_City value (or random among those with equal positive value) is the primary capital. Cities with lesser positive value are secondary capitals.

Gov_Center: The city with this effect is governmental center. Corruption and waste depends on distance to nearest such city.

Enable_Nuke: Allows the production of nuclear weapons.

Enable_Space: Allows the production of space components.

Specialist_Output: Specify what outputs a specialist is producing. Should be used with an OutputType requirement.

Output_Bonus: City production is increased by AMOUNT percent.

Output_Bonus_2: City production is increased by AMOUNT percent after Output_Bonus, so is multiplicative with it.

Output_Add_Tile: Add AMOUNT to each worked tile.

Output_Inc_Tile: Add AMOUNT to each worked tile that already has at least 1 output.

Output_Per_Tile: Increase tile output by AMOUNT percent.

Output_Tile_Punish_Pct: 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.

Output_Waste_Pct: Reduce waste by AMOUNT percent.

Force_Content: Make AMOUNT unhappy citizens content. Applied after martial law and unit penalties.

Give_Imm_Tech: Give AMOUNT techs immediately.

Conquest_Tech_Pct: Percent chance that a player conquering a city learns a tech from the former owner.

Growth_Food: Saves some food in the granary when a city grows (or shrinks). This effect controls how much food there will be in the city’s granary after growing, as a percentage of the foodbox at the new size, provided there was sufficient food before growing. This also reduces the aqueductloss penalty in the same fraction.

Note

This is traditionally used for the Granary.

Growth_Surplus_Pct: New in version 3.1.

How much of the excess food is kept when a city growth, as a percentage. For example, with a value of 100, a city with a granary full at 18/20 and generating 5 food would start the next turn with 3 bushels in its granary. With a value of 50, it would have only 1 bushel.

Have_Contact: If value > 0, gives contact to all the other players.

Have_Embassies: If value > 0, gives an embassy with all the other players owner has ever had contact with.

Irrigation_Pct: The tile gets value % of its terrain’s Irrigation_Food_Incr bonus value.

Note

This is how irrigation-like extras have an effect.

Mining_Pct: The tile gets value % of its terrain’s Mining_Shield_Incr bonus.

Note

This is how mine-like extras have an effect.

Make_Content: Make AMOUNT unhappy citizens content. Applied before martial law and unit penalties.

Make_Content_Mil: Make AMOUNT unhappy citizens caused by units outside of a city content.

Make_Content_Mil_Per: Make AMOUNT per unit of unhappy citizens caused by units outside of a city content.

Make_Happy: Make AMOUNT citizens happy.

Enemy_Citizen_Unhappy_Pct: There will be one extra unhappy citizen for each value/100 citizens of enemy nationality in the city.

No_Anarchy: No period of anarchy between government changes.

Note

This also neuters the Has_Senate effect.

Nuke_Proof: City is nuke proof.

Pollu_Pop_Pct: Increases pollution caused by each unit of population by AMOUNT percent (adds to baseline of 100%, i.e. 1 pollution per citizen).

Pollu_Pop_Pct_2: Increases pollution caused by each unit of population by AMOUNT percent (adds to baseline of 100%, i.e. 1 pollution per citizen). This factor is applied after Pollu_Pop_Pct, so is multiplicative with it.

Pollu_Prod_Pct: Increases pollution caused by shields by AMOUNT percent.

Health_Pct: Reduces possibility of illness (plague) in a city by AMOUNT percent.

Reveal_Cities: Immediately make all cities known.

Reveal_Map: Immediately make entire map known.

Border_Vision: Give vision on all tiles within the player’s borders. Happens during turn change. Does nothing unless the borders setting is set to “Enabled”. You can lock it if border vision rules are important to your ruleset.

Incite_Cost_Pct: Increases revolt cost by AMOUNT percent.

Unit_Bribe_Cost_Pct: Increases unit bribe cost by AMOUNT percent. Requirements are from the point of view of the target unit, not the briber.

Max_Stolen_Gold_Pm: The upper limit on the permille of the players gold that may be stolen by a unit doing the Steal Gold and the Steal Gold Escape actions. Evaluated against the city stolen from.

Maps_Stolen_Pct: The percent probability that the map of a tile is stolen in the actions Steal Maps and Steal Maps Escape. DiplRel reqs are unit owner to city owner. Requirements evaluated against tile or city not supported. Default value: 100%

Illegal_Action_Move_Cost: The number of move fragments lost when the player tries to do an action that turns out to be illegal. Only applied when the player was not aware that the action was illegal and its illegality therefore reveals new information.

Illegal_Action_HP_Cost: The number of hit points (HP) lost when the player tries to do an action that turns out to be illegal. Only applied when the player was not aware that the action was illegal and its illegality therefore reveals new information. Can kill the unit. If the action always causes the actor unit to end up at the target tile two consolation prizes are given. An area with the radius of the actor unit’s vision_radius_sq tiles is revealed. The player may also get contact with the owners of units and cites adjacent to the target tile.

Action_Success_Actor_Move_Cost: The number of move fragments lost when a unit successfully performs an action. Evaluated and done after the action is successfully completed. Added on top of any movement fragments the action itself subtracts.

Action_Success_Target_Move_Cost: The number of move fragments subtracted from a unit when someone successfully performs an action on it. Evaluated and done after the action is successfully completed. Added on top of any movement fragments the action itself subtracts. Only supported for actions that targets an individual unit.

Casus_Belli_Caught: Checked when a player is caught trying to do an action. Will cause an incident with the intended victim player if the value is 1 or higher. The incident gives the intended victim a casus belli against the actor player. A value of 1000 or higher is international outrage. International outrage gives every other player a casus belli against the actor.

Casus_Belli_Success: Checked when a player does an action to another player. Will cause an incident with the intended victim player if the value is 1 or higher. The incident gives the intended victim a casus belli against the actor player. A value of 1000 or higher is international outrage. International outrage gives every other player a casus belli against the actor.

Casus_Belli_Complete: Checked when a player completes an action that takes several turns against another player. Will cause an incident with the intended victim player if the value is 1 or higher. The incident gives the intended victim a casus belli against the actor player. A value of 1000 or higher is international outrage. International outrage gives every other player a casus belli against the actor. Only Pillage is currently supported.

Action_Odds_Pct: Modifies the odds of an action being successful. Some actions have a risk: the actor may get caught before he can perform it. This effect modifies the actor’s odds. A positive value helps him. A negative value makes it more probable that he will get caught. Currently supports the actions Incite City, Incite City Escape, Steal Gold, Steal Gold Escape, Steal Maps, Steal Maps Escape, Suitcase Nuke, Suitcase Nuke Escape, Sabotage City, Sabotage City Escape, Targeted Sabotage City, Targeted Sabotage City Escape, Sabotage City Production, Sabotage City Production Escape, Surgical Strike Building, Surgical Strike Production, Steal Tech, Steal Tech Escape Expected, Targeted Steal Tech, Targeted Steal Tech Escape Expected, and Spread Plague.

Size_Adj: Increase maximum size of a city by AMOUNT.

Size_Unlimit: Make the size of a city unlimited.

Unit_Slots: Number of unit slots city can have units in. New units cannot be built, nor can homecity be changed so that maintained units would use more slots than this. Single unit does not necessarily use single slot - that is defined separately for each unit type.

SS_Structural, SS_Component, SS_Module: 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.

Spy_Resistant: In diplomatic combat defending diplomatic units will get an AMOUNT percent bonus. All Spy_Resistant’s are summed before being applied.

Building_Saboteur_Resistant: If a spy specifies a target for sabotage, then she has an AMOUNT percent chance to fail.

Stealings_Ignore: When determining how difficult it is to steal a tech from enemy, AMOUNT previous times tech has been stolen from the city is ignored. Negative AMOUNT means that number of times tech has already been stolen from target city does not affect current attempt at all. With this effect it is possible to allow diplomats to steal tech multiple times from the same city, or make it easier for spies.

Move_Bonus: Add AMOUNT movement to units. Use “UnitClass” requirement with range of “Local” to give it a specific class of units only.

Unit_No_Lose_Pop: No population lost when a city’s defender is lost.

Unit_Recover: Units recover AMOUNT extra hitpoints (HP) per turn.

Upgrade_Unit: Upgrade AMOUNT obsolete units per turn.

Upkeep_Free: Improvements with AMOUNT or less upkeep cost become free to upkeep (others are unaffected).

Tech_Upkeep_Free: 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” this reduction is applied to every city.

No_Unhappy: No citizens in the city are ever unhappy.

Veteran_Build: Increases the veteran class of newly created units of this type. The total AMOUNT determines the veteran class (clipped at the maximum for the unit).

Veteran_Combat: Increases the chance of units of this type becoming veteran after combat by AMOUNT percent.

Combat_Rounds: Maximum number of rounds combat lasts. Unit is the attacker. Zero and negative values mean that combat continues until either side dies.

HP_Regen: Units that do not move recover AMOUNT percentage (rounded up) of their full hitpoints (HP) per turn.

Note

This effect is added automatically to implement HP recovery in cities. This behavior can be turned off by requiring the +HP_Regen_Min option in effects.ruleset.

HP_Regen_Min: Lower limit on HP_Regen. That is, the recovery percentage is the larger of HP_Regen and HP_Regen_Min.

Note

This effect is added automatically to implement HP recovery in cities. This behavior can be turned off by requiring the +HP_Regen_Min option in effects.ruleset.

City_Vision_Radius_Sq: Increase city vision radius in squared distance by AMOUNT tiles.

Note

This effect is added automatically for VisionLayers other than Main, with a value of 2, and a VisionLayer=Main requirement is added to any existing instances of this effect. This behaviour can be turned off by requiring the +VisionLayer option in effects.ruleset, allowing you to use VisionLayer requirements to specify which layer (Main, Stealth or Subsurface) the effect applies to.

Unit_Vision_Radius_Sq: Increase unit vision radius in squared distance by AMOUNT tiles.

Note

A VisionLayer=Main requirement is added automatically to any existing instances of this effect. This behaviour can be turned off by requiring the +VisionLayer option in effects.ruleset, allowing you to use VisionLayer requirements to specify which layer (Main, Stealth or Subsurface) the effect applies to.

Defend_Bonus: Increases defensive bonuses of units. Any unit requirements on this effect will be applied to the _attacking_ unit. Attackers with “BadWallAttacker” flag will have their firepower set to 1.

Attack_Bonus: Increases offensive bonuses of units. Unit requirements on this effect are the attacking unit itself.

Fortify_Defense_Bonus: Percentage defense bonus multiplicative with Defend_Bonus, usually given to fortified units. Unit requirements on this effect are the defending unit itself.

Gain_AI_Love: Gain AMOUNT points of “AI love” with AI’s.

Turn_Years: Year advances by AMOUNT each turn unless Slow_Down_Timeline causes it to be less.

Turn_Fragments: Year fragments advance by AMOUNT each turn.

Slow_Down_Timeline: 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.

Civil_War_Chance: Base chance in per cent of a nation being split by civil war when its capital is captured is increased by this AMOUNT. This percentage is in- creased by 5 for each city in civil disorder and reduced by 5 for each one celebrating.

City_Unhappy_Size: The maximum number of citizens in each city that are naturally content. In larger cities, new citizens above this limit start out unhappy. Before Empire_Size_Base and Empire_Size_Step are applied.

Empire_Size_Base: 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.

Empire_Size_Step: 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 if Empire_Size_Base is zero.

Max_Rates: The maximum setting for each tax rate is AMOUNT.

Martial_Law_Each: The AMOUNT of citizens pacified by each military unit giving martial law.

Martial_Law_Max: The maximum AMOUNT of units that will give martial law in city.

Rapture_Grow: Can rapture grow cities.

Revolution_Unhappiness: If value is greater than zero, it tells how many turns citizens will tolerate city disorder before government falls. If value is zero, government never falls.

Has_Senate: Has a senate that prevents declarations of war in most cases.

Inspire_Partisans: Partisan units (defined in units.ruleset) may spring up when this player’s cities are taken. The number of partisans created is a function of the city size. When multiple unit types have the Partisan flag, the game tries to choose one the player can build. If the player cannot build any, the first Partisan unit type is used. If the created partisans units have a non-zero pop_cost, the city will lose citizens accordingly.

Note

This effect can create units that the player could normally not build (because the tech hasn’t been researched or the NoBuild flag is set). It is your responsibility to set the appropriate requirements to avoid creating advanced units if a city is conquered in the early game.

Happiness_To_Gold: Make all Make_Content and Force_Content effects instead generate gold.

Max_Trade_Routes: Number of trade routes that city can establish. This is forced on trade route creation only. Existing trade routes are never removed due to reduction of effect value. This is to avoid micro-management, need to create same trade routes again after their max number has been temporarily down.

Fanatics: Units with “Fanatics” flag incur no upkeep.

No_Diplomacy: Cannot use any diplomacy.

Not_Tech_Source: Tech cannot be received from this player by any means.

Trade_Revenue_Bonus: One time trade revenue bonus is multiplied by \(2^{(\texttt{amount} \div 1000)}\). The AMOUNT value is taken from the caravan’s home city.

Trade_Revenue_Exponent: One time trade revenue bonus is raised to the \(1 + \frac{\texttt{amount}}{1000}\) power. This is applied before Trade_Revenue_Bonus.

Traderoute_Pct: 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.

Unhappy_Factor: Multiply unhappy unit upkeep by AMOUNT.

Upkeep_Factor: Multiply unit upkeep by AMOUNT.

Unit_Upkeep_Free_Per_City: 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.

Output_Waste: 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: For each tile in real distance that a city is from nearest Government Center, it gets \(\frac{\texttt{amount}}{100}\) of extra waste.

Output_Waste_By_Rel_Distance: City gets extra waste based on distance to nearest Government Center, relative to world size. The AMOUNT of this extra waste is \(\frac{\texttt{distance}\,\times\,\texttt{amount}}{100\,\times\,\texttt{max\_distance}}\)

Output_Penalty_Tile: When a tile yields more output than AMOUNT, it gets a penalty of -1.

Output_Inc_Tile_Celebrate: Tiles get AMOUNT extra output when city working them is celebrating.

Upgrade_Price_Pct: 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.

Unit_Shield_Value_Pct: Increase the unit’s value in shields by AMOUNT percent. When this effect is used to determine how many shields the player gets for the actions Recycle Unit and Help Wonder it gets access to unit state. When it is used to influence the gold cost of Upgrade Unit it only has access to unit type.

Retire_Pct: The chance that unit gets retired (removed) when turn changes. Retirement only happens if there are no enemy units or cities within a few tiles. This exists mainly to implement barbarian behavior.

Visible_Wall: Instruct the game to show specific buildings version of the city graphics. Zero or below are considered normal city graphics.

Tech_Cost_Factor: Factor for research costs.

Building_Build_Cost_Pct: Percentage added to building building cost.

Building_Buy_Cost_Pct: Percentage added to building buy cost.

Unit_Build_Cost_Pct: Percentage added to unit building cost.

Unit_Buy_Cost_Pct: Percentage added to unit buy cost.

Nuke_Improvement_Pct: Percentage chance that an improvement would be destroyed while nuking the city. Only regular improvements (not wonders) are affected. Improvements protected from Sabotage (Eg: City Walls) are not affected.

Nuke_Infrastructure_Pct: Percentage chance that an extra located within a nuclear blast area gets destroyed. Only “Infra” extras such as roads and irrigation are affected, and rmreqs are also checked. Note that an Extra requirement will match any extra on the tile, not only the one considered for destruction.

Shield2Gold_Factor: Factor in percent for the conversion of unit shield upkeep to gold upkeep. A value of 200 would transfer 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.

Tile_Workable: If value > 0, city can work target tile.

Migration_Pct: Increase the calculated migration score for the a city by AMOUNT in percent.

City_Radius_Sq: Increase the squared city radius by AMOUNT. Currently, this can only usefully have “MinSize”, “Building”, or “Tech” requirements.

City_Build_Slots: Increase the number of units with no population cost a city can build in a turn, if there are enough shields.

City_Image: The index for the city image of the given city style.

Victory: Positive value means that player wins the game.

Performance: Value is how much performance type culture city produces.

History: Value is how much history type (cumulative) culture city produces.

National_Performance: Value is how much performance type culture, not tied to any specific city, the nation produces.

National_History: Value is how much history type (cumulative) culture, not tied to any any specific city, the nation produces.

Infra_Points: City increases owner’s infra points by value each turn. If overall points are negative after all cities have been processed, they are set to 0.

Bombard_Limit_Pct: Bombardment may only reduce units to AMOUNT percent (rounded up) of their total hitpoints (HP). Unit requirements on this effect are the defending unit itself.

Note

This effect is added automatically with a value of 1 and no reqs. This behavior can be turned off by requiring the +Bombard_Limit_Pct option in effects.ruleset.

Wonder_Visible: If the value of this effect is larger than 0 for a small wonder, the wonder will be visible to all players and reported in the intelligence panel in the nations view. Great wonders are always visible to everyone through the wonders report (F7). When a small wonder is lost (for instance, because the city it is in is lost or some of its requirements become invalid), it also becomes visible to everyone (this is a limitation of the server).

Note

This effect is added automatically with a value of 1 for great wonders (since they are shown in the wonders report anyway). This behavior can be turned off by requiring the +Wonder_Visible option in effects.ruleset.

Nation_Intelligence: Controls the information available in the Nations View. See the detailed description.