Conclusion
Reading Unciv's difficulty file next to the code that uses it, the levels work in two halves. Settler, Chieftain and Warlord make things cheaper for you (Settler halves your unit, building and policy costs). Prince is the neutral baseline for costs and growth — those are all 100%, though the AI already gets a little extra unit supply (+20%).
From King upward, your costs and happiness stop changing — only your combat bonus against barbarians keeps shrinking. The rest of the difficulty comes from the AI: cheaper units and buildings, faster city growth, a bigger unit cap, extra starting units and free techs. On Deity, AI units and buildings cost half.
Every Difficulty Level
| Difficulty | Your tech cost | Your unit cost | Your building cost | Your policy cost | Base happiness | Your unhappiness | Your bonus vs barbarians | AI food needed to grow | AI unit cost | AI building cost | AI extra unit supply |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Settler | 90% | 50% | 50% | 50% | 15 | 40% | +75% | 160% | 175% | 160% | +0% |
| Chieftain | 95% | 67% | 67% | 67% | 12 | 60% | +50% | 130% | 130% | 130% | +0% |
| Warlord | 100% | 85% | 85% | 85% | 12 | 75% | +40% | 110% | 110% | 110% | +10% |
| Prince | 100% | 100% | 100% | 100% | 9 | 100% | +33% | 100% | 100% | 100% | +20% |
| King | 100% | 100% | 100% | 100% | 9 | 100% | +25% | 90% | 85% | 85% | +30% |
| Emperor | 100% | 100% | 100% | 100% | 9 | 100% | +20% | 85% | 80% | 80% | +30% |
| Immortal | 100% | 100% | 100% | 100% | 9 | 100% | +10% | 75% | 65% | 65% | +40% |
| Deity | 100% | 100% | 100% | 100% | 9 | 100% | +0% | 60% | 50% | 50% | +50% |
| Difficulty | Extra starting units for each AI civ | Free techs for AI |
|---|---|---|
| Settler | — | — |
| Chieftain | — | — |
| Warlord | — | — |
| Prince | — | — |
| King | era starting unit | Pottery |
| Emperor | era starting unit, Scout | Pottery, Animal Husbandry |
| Immortal | Worker, Scout, era starting unit, era starting unit | Pottery, Animal Husbandry, Mining |
| Deity | Settler, Worker, Scout, era starting unit, era starting unit, era starting unit | Pottery, Animal Husbandry, Mining, The Wheel |
Percentages are multipliers: 50% cost means half price; 160% food means AI cities need 60% more food to grow. Data from the game's own files (Civ V: Gods & Kings ruleset that ships with Unciv), read from the source at the commit of 2026-10-02. Updates and mods can change these numbers.
What Each Setting Does (Checked in the Code)
| Setting | Applies to | Effect |
|---|---|---|
| Tech / unit / building / policy cost | You (human players) | Multiplies your costs. The AI's own player-side values come from an easier internal level, not yours. |
| Base happiness | You | Starting happiness: 15 on Settler, 12 on Chieftain and Warlord, 9 from Prince up. |
| Unhappiness | You | Scales unhappiness from cities and population. |
| Bonus vs barbarians | Your units | A combat bonus against barbarians: +75% on Settler down to none on Deity. |
| AI food needed to grow | AI cities | Multiplies the food an AI city needs to grow — above 100% slows the AI, below speeds it up. |
| AI unit / building cost | AI civilizations | Multiplies AI production costs (wonders stay at 100% from King up). |
| AI extra unit supply | AI major civs | Raises how many units the AI can support before penalties. |
| Barbarians entering your land | Barbarians | On Settler barbarians never enter your territory; on Chieftain only from turn 60, Warlord from turn 20, and from the start on Prince and above. |
Which Level to Pick
- Learning the game: Chieftain or Warlord. You get cheaper costs and more happiness, and barbarians are kept out early.
- A fair game: Prince. Costs and growth are even on both sides; the AI gets +20% unit supply and trades techs with other AIs from Prince up.
- Challenge: King and above. Your costs no longer change, so each step up mainly means a stronger AI economy and a bigger AI head start.
FAQ
Does Deity make my research slower?
No. Your tech cost is 100% from Warlord up. Deity's difficulty is the AI's advantages.
Why is the AI weaker on Settler than me?
On Settler the AI needs 160% food to grow and pays 175% for units and 160% for buildings and wonders, while your costs are halved.
Is game speed included?
No. Game speed multiplies costs separately on top of difficulty.
Do these apply to city-states?
City-states have their own rules (for example, they pay 150% for units), so the AI rows here are about major civilizations.
Continue reading
More Unciv guides
Unciv guide home · All 34 Civilizations · City Growth and Happiness · City-States: Bonuses and Quests · Combat: Damage Formula and Calculator · Early Game: Key Numbers and Ancient Ruins · Every Building: Cost, Upkeep and Effects · Every Promotion and Effect · Every Religion Belief · Every Unit's Stats by Era · Every World and National Wonder · Game Speed and Starting Era · Great People: Points and the Shared Pool · Mods: Installing and Popular Picks · Multiplayer: Playing Online · Social Policies and Policy Cost · Tech Tree: Every Tech and Unlock · Terrain, Resources and Improvements · Unciv vs Civilization V · Victory Conditions