The effects.ruleset file contains all effects in play in a Freeciv scenario. They have the following form (this is perhaps the most complicated example I could find): [effect_hydro_plant] name = "Output_Bonus" value = 25 reqs = { "type", "name", "range" "Building", "Factory", "City" "Building", "Hydro Plant", "City" "OutputType", "Shield", "Local" } nreqs = { "type", "name", "range" "Building", "Hoover Dam", "Player" "Building", "Nuclear Plant", "City" } 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 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. Lastly there is the nreqs table which is the opposite of the reqs field, these are conditions which prevent the effect from taking place. Any one of the nreq conditions will prevent the effect from taking effect. Value is integral amount 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", "World". Some requirement types may only work at certain ranges; this is not yet documented. In particular, at present, "Continent" effects can affect only cities and units in cities. A requirement may have a 'survives' field, and if this is '1', the effect survives destruction (wonders only, at world or player range only). A requirement may have a 'negated' field, and if this is '1', the requirement is negated. A requirement type is the type of the requirement and can be one of "None", "Tech", "Gov", "Building", "Special", "Base", "Terrain", "UnitType", "UnitFlag", "UnitClass", "UnitClassFlag", "Nation", "OutputType", "MinYear", "MinSize", "AI", "TerrainClass", "TerrainAlter", or "CityTile". MinSize is the minimum size of a city required. AI is ai player difficulty level. TerrainClass is either "Land" or "Oceanic". Only "Center" is supported as CityTile type. Effect types ============ Tech_Parasite Gain any advance known already by amount number of other players. 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). Airlift Allow airlift to/from a city. Any_Government Allow changing to any form of government regardless of tech prerequisites. Capital_City The city with this effect is the capital 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_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. Growth_Food Food left after cities grow or shrink is amount percent of the capacity of the city's foodbox. This also affects the 'aqueductloss' penalty. Have_Embassies Like having embassies with all other players. 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. No_Anarchy No period of anarchy between government changes. (This also neuters the Has_Senate effect.) Nuke_Proof City is nuke proof. Pollu_Pop_Pct Increases pollution caused by population by amount percent. 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. Incite_Cost_Pct Increases revolt cost by amount percent. Size_Adj Increase maximum size of a city by amount. Size_Unlimit Make the size of a city unlimited. SS_Structural, SS_Component and 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 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. 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 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. No_Unhappy No citizens in the city are ever unhappy. Veteran_Build New land units of this type have veteran class 1. The amount value is ignored, so that you can have multiple Veteran_Build effects, and units will only get 1 free veterancy level. This is considered a feature at the moment. Veteran_Combat Increases the chance of units of this type becoming veteran after combat by amount percent. HP_Regen Units that do not move recover amount percentage of their full hitpoints per turn. City_Vision_Radius_Sq Increase city vision radius in squared distance by amount tiles. Unit_Vision_Radius_Sq Increase unit vision radius in squared distance by amount tiles. Defend_Bonus 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. Attackers with "BadWallAttacker" flag will have their firepower set to 1. No_Incite City cannot be incited. 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. 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. 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. Unbribable_Units Units cannot be bribed. Revolution_When_Unhappy If a city owned by this player is in revolt for more than two turns, government 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. Happiness_To_Gold Make all Make_Content and Force_Content effects instead generate gold. Fanatics Special case for Fanatics unit only. No_Diplomacy Cannot use any diplomacy. Trade_Revenue_Bonus Trade revenue is multiplied by pow(2, amount/1000). The amount value is taken from the caravan's home city. 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 your capital, it gets amount of extra waste. 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. Visible_Wall Positive amount only instructs clients to use wall graphics for city. Tech_Cost_Factor Factor for research costs. 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. Irrig_Possible If value > 0, unit can irrigate target tile. In addition to requirements given to this effect, unit must also have Settlers flag. 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.