Difficulty level (Civ4)

The difficulty level is a game setting in Civilization IV that allows players to compete against AI opponents matched to their skills and desire for challenge. In order from lowest to highest, the difficulty levels are as follows:
* Settler
* Chieftain
* Warlord
* Noble
* Prince
* Monarch
* Emperor
* Immortal
* Deity
Since the computer players are not controlled by advanced AI (i.e., cannot learn from and react to the player's strategies by changing their own accordingly), but instead behave based on a very long list of if-then statements, the game makes the AI leaders more challenging opponents by giving them advantages on higher difficulty levels. The bonuses conferred to both human and AI players on each difficulty level are listed in the table below.
All of the information presented here comes from a forum post on CivFanatics and the game's XML files.https://forums.civfanatics.com/threads/difficulty-levels-spreadsheet.158130/
Element 	Settler 	Chieftain 	Warlord 	Noble	Prince	Monarch	Emperor 	Immortal 	Deity
iFreeWinsVsBarbs 	5 	4 	3 	2 	1 	0 	0 	0 	0
iAnimalAttackProb 	0 	25 	50 	75 	90 	95 	98 	99 	100
iStartingLocPercent 	10 	20 	30 	40 	50 	60 	70 	80 	90
iGold 	0 	0 	0 	0 	0 	0 	0 	0 	0
iFreeUnits 	24 	18 	12 	8 	6 	4 	3 	2 	1
iUnitCostPercent 	20 	30 	40 	50 	60 	70 	80 	90 	100
iResearchPercent 	60 	75 	90 	100 	110 	115 	120 	125 	130
iDistanceMaintenancePercent 	45 	55 	65 	75 	85 	90 	95 	100 	100
iNumCitiesMaintenancePercent 	40 	50 	60 	70 	80 	85 	90 	95 	100
iMaxNumCitiesMaintenance 	4 	4 	5 	5 	6 	6 	7 	7 	8
iCivicUpkeepPercent 	50 	60 	70 	80 	90 	95 	100 	100 	100
iInflationPercent 	60 	70 	80 	90 	95 	100 	100 	100 	100
iHealthBonus 	4 	4 	3 	3 	2 	2 	1 	1 	1
iHappyBonus 	6 	6 	5 	5 	4 	4 	3 	3 	3
iAttitudeChange 	2 	1 	0 	-1 	-1 	-1 	-1 	-1 	-1
iNoTechTradeModifier 	100 	90 	80 	70 	60 	50 	40 	30 	20
iTechTradeKnownModifier 	-100 	-50 	-25 	0 	0 	0 	0 	0 	0
iUnownedTilesPerGameAnimal 	100 	80 	60 	50 	40 	35 	30 	25 	20
iUnownedTilesPerBarbarianUnit 	150 	100 	80 	60 	50 	40 	35 	30 	25
iUnownedWaterTilesPerBarbarianUnit	3000 	2400 	2200 	2000 	1800 	1600 	1400 	1200 	1000
iUnownedTilesPerBarbarianCity 	160 	150 	140 	130 	120 	110 	100 	90 	80
iBarbarianCreationTurnsElapsed 	50 	45 	40 	35 	30 	25 	20 	15 	10
iBarbarianCityCreationTurnsElapsed	55 	50 	45 	40 	35 	30 	25 	20 	15
iBarbarianCityCreationProb 	4 	5 	5 	6 	6 	7 	7 	8 	8
iAnimalBonus 	-70 	-60 	-50 	-40 	-30 	-20 	-10 	-5 	0
iBarbarianBonus 	-40 	-30 	-20 	-10 	-5 	0 	0 	0 	0
iAIAnimalBonus 	-70 	-70 	-70 	-70 	-70 	-70 	-70 	-70 	-70
iAIBarbarianBonus 	-40 	-40 	-40 	-40 	-40 	-40 	-40 	-40 	-40
iStartingDefenseUnits 	0 	0 	0 	0 	0 	0 	0 	0 	0
iStartingWorkerUnits 	0 	0 	0 	0 	0 	0 	0 	0 	0
iStartingExploreUnits 	0 	0 	0 	0 	0 	0 	0 	0 	0
iAIStartingUnitMultiplier 	0 	0 	0 	0 	0 	0 	0 	0 	1
iAIStartingDefenseUnits 	0 	0 	0 	0 	0 	1 	2 	3 	4
iAIStartingWorkerUnits 	0 	0 	0 	0 	0 	1 	1 	2 	2
iAIStartingExploreUnits 	0 	0 	0 	0 	1 	0 	1 	1 	1
iBarbarianDefenders 	1 	1 	1 	2 	2 	3 	3 	4 	4
iAIDeclareWarProb 	25 	50 	75 	100 	100 	100 	100 	100 	100
iAIWorkRateModifier 	0 	0 	0 	0 	10 	20 	50 	75 	100
iAIGrowthPercent 	160 	130 	110 	100 	95 	90 	85 	80 	80/60**
iAITrainPercent 	160 	130 	110 	100 	95 	90 	85 	80 	60
iAIWorldTrainPercent 	160 	130 	110 	100 	100 	100 	100 	100 	100
iAIConstructPercent 	160 	130 	110 	100 	95 	90 	85 	80 	60
iAIWorldConstructPercent 	160 	130 	110 	100 	100 	100 	100 	100 	100
iAICreatePercent 	160 	130 	110 	100 	95 	90 	85 	80 	60
iAIWorldCreatePercent 	160 	130 	110 	100 	100 	100 	100 	100 	100
iAICivicUpkeepPercent 	100 	100 	100 	100 	95 	90 	85 	80 	60
iAIUnitCostPercent 	100 	100 	100 	100 	95 	90 	85 	80 	60
iAIUnitSupplyPercent 	50 	45 	40 	35 	30 	25 	20 	15 	10
iAIUnitUpgradePercent 	45 	40 	35 	30 	25 	20 	15 	10 	5
iAIInflationPercent 	100 	90 	80 	70 	60 	50 	40 	30 	20
iAIWarWearinessPercent 	100 	90 	80 	70 	60 	50 	40 	30 	20
iAIPerEraModifier 	0 	0 	0 	0 	-1 	-2 	-3 	-4 	-5
High Gold* 	4 	4 	3 	3 	2 	1 	1 	N/A 	N/A
Low Gold* 	2 	2 	3 	4 	4 	4 	5 	5 	5
Map* 	1 	1 	2 	2 	2 	2 	2 	2 	1
Settler* 	2 	2 	1 	N/A 	N/A 	N/A 	N/A 	N/A 	N/A
Warrior* 	2 	2 	2 	2 	2 	2 	1 	1 	1
Scout* 	1 	1 	1 	1 	1 	1 	1 	1 	1
Worker* 	2 	2 	1 	N/A 	N/A 	N/A 	N/A 	N/A 	N/A
Experience* 	1 	1 	1 	2 	2 	2 	1 	1 	1
Healing* 	1 	1 	1 	1 	1 	1 	1 	1 	1
Tech* 	4 	3 	3 	2 	2 	2 	2 	2 	2
Barbarian Weak* 	N/A 	1 	1 	2 	3 	3 	3 	3 	2
Barbarian Strong* 	N/A 	N/A 	1 	1 	1 	2 	3 	4 	6
FreeTechs 	The Wheel, Agriculture, Mining	The Wheel, Agriculture	The Wheel	None 	None 	None 	None 	None 	None
AIFreeTechs 	None 	None 	None 	None 	None 	Archery	Archery, Hunting	Archery, Hunting, Agriculture	Archery, Hunting, Agriculture, The Wheel
* This element is listed under the heading "Goodies (20)" in the XML file. It indicates the chance (x-in-20) of a "goody hut" yielding this result when "popped" by the player.
** 60 on the original CIV4HandicapInfo, but 80 on Beyond the Sword CIV4HandicapInfo.
== References ==
== See also ==
* Difficulty level in other games
Category:Game concepts (Civ4)