Hearth and Hamlet Mechanics: Formulas & Rules Explained
Hearth and Hamlet mechanics explained: building costs, worker tiers, happiness, population growth, trade quality, expeditions, and battle resolution formulas.
The Hearth and Hamlet mechanics are the eight rules recovered from the game’s build 0.80 data that govern building costs, worker counts, happiness, population, trade, expeditions, harvesting, and combat. They explain how the game calculates results behind the scenes, but the numbers come from static game files and are not presented as final full-game values.
The short answer
- Eight mechanics are documented in the build 0.80 data
- Building cost = the level’s base-cost rank multiplied by its resource ratio, rounded
- Workers come from population bands, each with its own ratio
- Happiness, trade quality, and expedition size all have their own formulas
- Treat every formula as build 0.80 data, subject to change in future patches
Building cost calculation
Building resource costs are not hand-tuned per building. They follow a rule: a building’s cost equals its level’s base-cost rank multiplied by a resource ratio, then rounded to the nearest whole unit. The data defines 31 base-cost ranks, numbered 0 through 30, with the highest base cost reaching 30,000,000.
That is why two different buildings often share a familiar cost shape — they sit on the same rank and only differ by their resource ratio. When a cost looks enormous late in the game, it is usually the rank climbing, not an arbitrary spike. See the buildings reference for individual building costs.
Worker population tiers
The number of assignable workers is calculated in population bands rather than a flat percentage. Each band covers a span of population and contributes at its own ratio, and the floating result is converted to an integer for display.
| Tier | Band size | Ratio |
|---|---|---|
| Tier 0 | 20 | 0.34 |
| Tier 1 | 100 | 0.12 |
| Tier 2 | 250 | 0.07 |
| Tier 3 | 900 | 0.05 |
| Tier 4 | 3,500 | 0.014 |
| Tier 5 | 10,000 | 0.006 |
| Tier 6 | 30,000 | 0.005 |
The ratios shrink as the band grows, so a kingdom does not turn every citizen into a worker — the worker share falls as population climbs. Demo v1.0.46 rebalanced worker quantities, so any ratio quoted from an older demo video may already be wrong. Read more in the workers reference.
Population growth and housing
Population growth is driven by surplus Food and by happiness, while housing sets a hard cap: population cannot grow beyond available housing. The starting population is 1, and the starting base happiness is 1, before any modifiers apply.
In practice this means two things. First, keep Food in surplus if you want people to arrive, because a full but shrinking stockpile still slows growth. Second, build housing before you need it, since a full housing bar silently stops new arrivals. The demo shows Food surplus producing a low, medium, or high population-growth multiplier, which matches the surplus-Food rule in the mined data.
Happiness and production
Settlement happiness contributes to global production, and it is assembled from ten separate modifier groups: Tavern, Church, Conscription, Battle, Alchemist, Tax, Food, Immigration, Luxury, and Foreign tax. Each group adjusts the total independently, which is why one big policy change can shift production across every resource at once.
Because conscription is its own modifier, recruiting too many soldiers lowers happiness and therefore production — the mechanic behind the demo’s warning that pulling people into the military hurts morale. Policies and laws shape most of these modifiers, so read the policies reference when you want to move happiness deliberately.
Manual harvesting and critical harvests
Holding the harvest input produces resources through a chain of click power, resource multipliers, global multipliers, and critical-harvest rules. The starting click power is 1, the game assumes 4 clicks per second, and a critical harvest applies a 12× multiplier to a single tick.
That explains the big yellow numbers that pop up during play: they are critical hits, not a bug. The starting click power of 1 also means early manual harvesting is slow, and only the multiplier stack — research, happiness, tools — makes the leader’s own clicks meaningful later.
Trade quality
Trade quality adds a cost premium and changes the profit multiplier on the same goods. Higher quality costs more but returns more.
| Quality | Cost modifier | Profit multiplier |
|---|---|---|
| Normal | 0% | 1.2× |
| Superior | +10% | 1.6× |
| Premium | +20% | 2× |
The trade-off is a real decision: Premium doubles the profit multiplier but charges a fifth more upfront, so it pays only when the route’s base margin is healthy. See the trade reference for how trade routes and quality fit the wider economy.
Expedition capacity
Caravans and ships carry goods in three shipment sizes, which set how much a single expedition can move. Ships dwarf caravans because sea routes exist to move bulk goods over long distances.
| Transport | Small | Moderate | Large |
|---|---|---|---|
| Caravan | 1,000 | 3,000 | 10,000 |
| Ship | 25,000 | 90,000 | 180,000 |
The gap between a large caravan and a small ship is the point where maritime trade starts to matter: once your production outgrows 10,000 per expedition, ships become the only way to keep shipments full.
Battle resolution
Combat compares your soldiers against an enemy group using five values: attack, defence, attack speed, travel speed, and difficulty. The data tracks attack, defence, attack speed, and travel speed for your soldiers, and applies the same profile to each of the 12 enemy types.
Travel speed is worth watching because it sets how fast a raid closes the distance, which is the timer behind the pre-raid checklist. Attack speed and difficulty together decide how dangerous an enemy actually is, not just its raw attack number. The full raids reference lists the 12 enemy profiles and the defense buildings that counter them.
The video above shows the mechanics at work in the demo: manual harvesting, critical hits, population growth, and the happiness multiplier.
Build 0.80 vs final mechanics
All eight mechanics are marked as enabled in the build 0.80 data, but that package is a static snapshot of the game files, not a promise about current balance. The formulas are the most reliable thing here — the exact coefficients, ranks, and ratios can shift between builds. When a number matters, verify it against the version you are playing and treat older values as to be confirmed.
Start with the beginner guide to see these rules in play, then dig into the workers, trade, and research-tree references as each system unlocks.
Sources: Steam store page · Hearth and Hamlet game database — mechanics