The difficulty level is a game setting in Civilization V 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
- Prince
- King
- Emperor
- Immortal
- Deity
Since the computer players are controlled not by actual AI (like Siri or self-driving cars), but by simple sets of rules which don't result in very effective play, 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 tables below.
All of the information presented here comes from an info page on CivFanatics and the game's XML files.[1]
In Vanilla and Gods & Kings
Player Bonuses
Players receive gameplay bonuses that diminish as the chosen difficulty level increases. The AI plays on Chieftain difficulty and receives all of the appropriate bonuses.
| Element | Settler | Chieftain | Warlord | Prince | King | Emperor | Immortal | Deity |
|---|---|---|---|---|---|---|---|---|
| Advanced Start Points* | 150% | 130% | 110% | 100% | 90% | 85% | 80% | 75% |
| Base Happiness | 15 | 12 | 12 | 9 | 9 | 9 | 9 | 9 |
| Extra Happiness Per Luxury | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
| Unhappiness Per City | 40% | 60% | 75% | 100% | 100% | 100% | 100% | 100% |
| Unhappiness Per Population | 40% | 60% | 75% | 100% | 100% | 100% | 100% | 100% |
| Production Free Units | 10 | 7 | 7 | 5 | 5 | 5 | 5 | 5 |
| Production Free Units Per City | 3 | 3 | 2 | 2 | 2 | 2 | 2 | 2 |
| Route Cost | 34% | 50% | 75% | 100% | 100% | 100% | 100% | 100% |
| Unit Cost | 50% | 67% | 85% | 100% | 100% | 100% | 100% | 100% |
| Building Cost | 50% | 67% | 85% | 100% | 100% | 100% | 100% | 100% |
| Research Cost | 90% | 95% | 100% | 100% | 100% | 100% | 100% | 100% |
| Policy Cost | 50% | 67% | 85% | 100% | 100% | 100% | 100% | 100% |
| City Production Num Options Considered | 10 | 4 | 3 | 2 | 2 | 2 | 2 | 2 |
| Tech Num Options Considered | 10 | 4 | 3 | 2 | 2 | 2 | 2 | 2 |
| Policy Num Options Considered | 10 | 4 | 3 | 2 | 2 | 2 | 2 | 2 |
| Attitude Change* | 2 | 1 | 0 | -1 | -1 | -1 | -1 | -1 |
| No Tech Trade Modifier* | 100% | 90% | 80% | 70% | 50% | 40% | 30% | 20% |
| Tech Trade Known Modifier* | -100% | -50% | -25% | 0% | 0% | 0% | 0% | 0% |
| Barb Camp Gold | 50 | 40 | 30 | 25 | 25 | 25 | 25 | 25 |
| Barb Spawn Mod | 8 | 5 | 3 | 0 | 0 | 0 | 0 | 0 |
| Barbarian Bonus | 75 | 50 | 40 | 33 | 25 | 20 | 10 | 0 |
| Turn Barbarians Can Enter Player Land | 10,000 | 60 | 20 | 0 | 0 | 0 | 0 | 0 |
| Barbarian Land Target Range | 2 | 3 | 4 | 5 | 5 | 6 | 7 | 8 |
| Barbarian Sea Target Range | 4 | 6 | 8 | 10 | 12 | 15 | 18 | 20 |
* This element is either a holdover from Civilization IV or is never used in the code, so it has no effect on gameplay.
AI Bonuses
The player's chosen difficulty level also affects the AI leaders. The gameplay bonuses they receive from Chieftain difficulty are cumulative with the bonuses below, so if the player chooses Deity difficulty, the AI will receive 60% of 60% (or 36%) of the normal 
Unhappiness Unhappiness from its cities and population.
| Element | Settler | Chieftain | Warlord | Prince | King | Emperor | Immortal | Deity |
|---|---|---|---|---|---|---|---|---|
| Free Techs | None | None | None | None | Pottery | Pottery, Animal Husbandry | Pottery, Animal Husbandry, Mining | Pottery, Animal Husbandry, Mining, The Wheel |
| Barbarian Bonus | 45% | 50% | 55% | 60% | 60% | 60% | 60% | 60% |
| Starting Settler Bonus | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
| Starting Defense Units | 0 | 0 | 0 | 0 | 1 | 1 | 2 | 2 |
| Starting Worker Units | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 2 |
| Starting Explore Units | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 |
| Declare War Probability | 0% | 75% | 85% | 100% | 100% | 100% | 100% | 100% |
| Work Rate Bonus | 0% | 0% | 0% | 0% | 20% | 50% | 75% | 100% |
| Unhappiness | 100% | 100% | 100% | 100% | 90% | 85% | 75% | 60% |
| Growth Rate1 | 160% | 130% | 110% | 100% | 90% | 85% | 75% | 60% |
| Train Rate2 | 175% | 130% | 110% | 100% | 85% | 80% | 65% | 50% |
| World Train Rate | 160% | 130% | 110% | 100% | 100% | 100% | 100% | 100% |
| Construction Rate3 | 160% | 130% | 110% | 100% | 85% | 80% | 65% | 50% |
| World Construction Rate4 | 160% | 130% | 110% | 100% | 100% | 100% | 100% | 100% |
| Create Rate5 | 160% | 130% | 110% | 100% | 85% | 80% | 65% | 50% |
| World Create Rate6 | 160% | 130% | 110% | 100% | 100% | 100% | 100% | 100% |
| Building Cost7 | 100% | 100% | 100% | 100% | 85% | 80% | 65% | 50% |
| Unit Cost8 | 100% | 100% | 100% | 85% | 80% | 75% | 65% | 50% |
| Unit Supply | 0% | 0% | 10% | 20% | 30% | 30% | 40% | 50% |
| Per Era Modifier | 0 | 0 | 0 | 0 | -2 | -3 | -4 | -5 |
| Advanced Start Points* | 100% | 100% | 100% | 100% | 120% | 135% | 150% | 170% |
1 This element applies to the amount of 
Food Food that cities must store to increase their 
Population Population.
2 This element applies to the 
Production Production and 
Faith Faith costs of units.
3 This element applies to the Production Production costs of buildings.
4 This element applies to the Production Production costs of wonders.
5 This element applies to the Production Production costs of national projects, such as the Manhattan Project.
6 This element applies to the amount of Production Production that must be contributed to complete international projects, such as the World's Fair.
7 This element applies to the 
Gold Gold maintenance costs of buildings.
8 This element applies to the Gold Gold maintenance costs of units.
* This element is either a holdover from Civilization IV or is never used in the code, so it has no effect on gameplay.
In Brave New World
Player Bonuses
Players receive gameplay bonuses that diminish as the chosen difficulty level increases. The AI plays on a special difficulty level (as detailed under "AI" in the table below) and receives all of the appropriate bonuses.
| Element | Settler | Chieftain | Warlord | Prince | King | Emperor | Immortal | Deity | AI |
|---|---|---|---|---|---|---|---|---|---|
| Advanced Start Points* | 150% | 130% | 110% | 100% | 90% | 85% | 80% | 75% | 100% |
| Base Happiness | 15 | 12 | 12 | 9 | 9 | 9 | 9 | 9 | 15 |
| Extra Happiness Per Luxury | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Unhappiness Per City | 40% | 60% | 75% | 100% | 100% | 100% | 100% | 100% | 90% |
| Unhappiness Per Population | 40% | 60% | 75% | 100% | 100% | 100% | 100% | 100% | 90% |
| Production Free Units | 10 | 7 | 7 | 5 | 5 | 5 | 5 | 5 | 7 |
| Production Free Units Per City | 3 | 3 | 2 | 2 | 2 | 2 | 2 | 2 | 3 |
| Route Cost | 34% | 50% | 75% | 100% | 100% | 100% | 100% | 100% | 50% |
| Unit Cost | 50% | 67% | 85% | 100% | 100% | 100% | 100% | 100% | 75% |
| Building Cost | 50% | 67% | 85% | 100% | 100% | 100% | 100% | 100% | 75% |
| Research Cost | 90% | 95% | 100% | 100% | 100% | 100% | 100% | 100% | 85% |
| Policy Cost | 50% | 67% | 85% | 100% | 100% | 100% | 100% | 100% | 75% |
| City Production Num Options Considered | 10 | 4 | 3 | 2 | 2 | 2 | 2 | 2 | 2 |
| Tech Num Options Considered | 10 | 4 | 3 | 2 | 2 | 2 | 2 | 2 | 2 |
| Policy Num Options Considered | 10 | 4 | 3 | 2 | 2 | 2 | 2 | 2 | 2 |
| Attitude Change* | 2 | 1 | 0 | -1 | -1 | -1 | -1 | -1 | -1 |
| No Tech Trade Modifier* | 100% | 90% | 80% | 70% | 50% | 40% | 30% | 20% | 70% |
| Tech Trade Known Modifier* | -100% | -50% | -25% | 0% | 0% | 0% | 0% | 0% | 0% |
| Barb Camp Gold | 50 | 40 | 30 | 25 | 25 | 25 | 25 | 25 | 25 |
| Barb Spawn Mod | 8 | 5 | 3 | 0 | 0 | 0 | 0 | 0 | 0 |
| Barbarian Bonus | 70 | 60 | 50 | 40 | 30 | 20 | 10 | 0 | 40 |
| Turn Barbarians Can Enter Player Land | 10,000 | 60 | 20 | 0 | 0 | 0 | 0 | 0 | 0 |
| Barbarian Land Target Range | 2 | 3 | 4 | 5 | 5 | 6 | 7 | 8 | 5 |
| Barbarian Sea Target Range | 4 | 6 | 8 | 10 | 12 | 15 | 18 | 20 | 10 |
* This element is either a holdover from Civilization IV or is never used in the code, so it has no effect on gameplay.
AI Bonuses
The player's chosen difficulty level also affects the AI leaders. The gameplay bonuses they receive from their special difficulty level are cumulative with the bonuses below, so if the player chooses Deity difficulty, the AI will receive 90% of 75% (or 67.5%) of the normal Unhappiness Unhappiness from its cities and population.
| Element | Settler | Chieftain | Warlord | Prince | King | Emperor | Immortal | Deity |
|---|---|---|---|---|---|---|---|---|
| Free Techs | None | None | None | None | Pottery | Pottery, Animal Husbandry, Mining | Pottery, Animal Husbandry, Mining, Archery | Pottery, Animal Husbandry, Mining, Archery, The Wheel |
| Barbarian Bonus | 75% | 70% | 60% | 60% | 60% | 60% | 60% | 60% |
| Starting Settler Bonus | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
| Starting Defense Units | 0 | 0 | 0 | 0 | 1 | 1 | 2 | 2 |
| Starting Worker Units | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 2 |
| Starting Explore Units | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 |
| Declare War Probability | 0% | 75% | 85% | 100% | 100% | 100% | 100% | 100% |
| Work Rate Bonus | 0% | 0% | 0% | 0% | 20% | 50% | 75% | 100% |
| Unhappiness | 100% | 100% | 100% | 100% | 100% | 90% | 85% | 75% |
| Growth Rate1 | 160% | 130% | 110% | 100% | 90% | 80% | 70% | 55% |
| Train Rate2 | 175% | 130% | 110% | 100% | 85% | 80% | 65% | 50% |
| World Train Rate | 160% | 130% | 110% | 100% | 100% | 100% | 100% | 100% |
| Construction Rate3 | 160% | 130% | 110% | 100% | 85% | 75% | 60% | 50% |
| World Construction Rate4 | 160% | 130% | 110% | 100% | 100% | 100% | 100% | 100% |
| Create Rate5 | 160% | 130% | 110% | 100% | 85% | 80% | 65% | 50% |
| World Create Rate6 | 160% | 130% | 110% | 100% | 100% | 100% | 100% | 100% |
| Building Cost7 | 100% | 100% | 100% | 100% | 85% | 80% | 65% | 50% |
| Unit Cost8 | 100% | 100% | 100% | 85% | 80% | 75% | 65% | 50% |
| Unit Supply | 0% | 0% | 10% | 20% | 30% | 30% | 40% | 50% |
| Per Era Modifier | 0 | 0 | 0 | 0 | -2 | -3 | -4 | -5 |
| Advanced Start Points* | 100% | 100% | 100% | 100% | 120% | 135% | 150% | 170% |
| Free XP9 | 0 | 0 | 0 | 0 | 10 | 10 | 30 | 30 |
| Free XP Percent10 | 0% | 0% | 0% | 0% | 0% | 25% | 50% | 100% |
1 This element applies to the amount of Food Food that cities must store to increase their Population Population.
2 This element applies to the Production Production and Faith Faith costs of units.
3 This element applies to the Production Production costs of buildings.
4 This element applies to the Production Production costs of wonders.
5 This element applies to the Production Production costs of national projects, such as the Manhattan Project.
6 This element applies to the amount of Production Production that must be contributed to complete international projects, such as the World's Fair.
7 This element applies to the Gold Gold maintenance costs of buildings.
8 This element applies to the Gold Gold maintenance costs of units.
9 This element applies to the starting XP of military units.
10 This element applies to the number of XP that military units earn from combat.
* This element is either a holdover from Civilization IV or is never used in the code, so it has no effect on gameplay.