Every building, troop and expansion of your realm is paid for with four resources: wood, stone, iron and gold. Each village has its own stock and its own production. What one village gathers doesn't show up in the others until you send it by caravan.
The four extractors
Each resource has exactly one building that produces it:
Production is continuous and counted per hour, including while you're away from the game. Each level's output, already using this server's settings, is on each extractor's page. The four don't yield the same: compare the pages before deciding which one to upgrade.
The curve per level
Upgrading an extractor always raises production, but each new level adds proportionally less than the one before. The high levels are still the ones that yield the most; they just don't multiply your income in step with the level. That's a deliberate brake: more production pays for bigger buildings, which bring even more production, and without these diminishing returns the snowball would get out of hand.
Production isn't multiplied by the server speed either. On a fast server, construction and training move faster, but hourly income stays the same (see Server pace).
Production floor
Even with no extractor built, a village produces a little of each resource "in the background": a small fraction of what the extractor would yield at its first level. It keeps new players, or anyone who's been away for a while, from coming back to an empty stock. It's only a floor: real income comes from the buildings. The first-level value on each extractor's page already includes this floor.
What raises production
- Temple: each level adds +7% to the production of all four resources in the village where it stands.
- Hall of Heroes in secondary villages: since heroes are only recruited in the capital, the Hall in your other villages doesn't recruit and becomes a production bonus. Its page shows how much per level (more in Founding new villages).
- Guild: the Deep Veins track of the Order Tree raises the production of all four resources for every member, and oases held by the guild can boost one specific resource.
- Omens: some cards on your Table raise production, like Serf's Sickle. Others charge production as the price of what they offer.
Other sources of resources
Production is your steady income, but not the only one. Quests and achievements pay resources, and so does plunder: attacking PvE targets and other players brings back whatever your troops can carry.
Plunder from PvE targets has a weekly cap of 3,000,000,000 resources combined per account. Once you hit it, those targets keep paying coins, experience and items, but no resources, until the week turns over (Monday, 00:00 Brasília time). Plunder from other players doesn't count toward this cap.
Plunder and rewards land in your stock even above the Warehouse limit; production doesn't. What happens when it fills up is in Warehouse and storage.