A resource's Gather Rate is the speed at which it is generated, given as "X resources produced per 30 seconds of game time" (altered by game speed). A resource's gather rate can be increased by building certain production buildings and linking rare resources with a Merchant.
For balancing reasons there's a Commerce Limit which caps the current production rate. At the beginning, resource production is capped at 70 for each resource per 30 seconds. The commerce limit can be increased by researching Commerce technologies. The limit of the Gather rate is +999 when Global Prosperity, a Future Technology, is researched.
In single-player Quick Battle and in Multiplayer Games there is an option called Turbo Resources, which increases resource production by 50% - the gather rates become "resources per 20 seconds". Additionally, the gather rate is affected by the AI difficulty setting, with the Toughest setting giving the AI the resources per 20 seconds instead of 30. It is also affected by the player Skill setting in Multiplayer Games.
Citizens gather resources once they reach the resource building, such as a Farm or a Woodcutter's Camp. Although they will move around, the gather rate is not affected by this, nor is it affected if they are blocked from moving (as long as they have started gathering). Citizens may move around when attacked, but the gather rate will be unaffected. However, if they are ordered away (such as to garrison), they will stop gathering immediately.
- Each city provides a basic income of 10 food and 10 timber, meaning it generates 10 food and 10 timber per 30 seconds.
- The Farm has a Food gather rate of 10, which means, it produces 10 Food per 30 seconds (or 1 unit of Food every 3 seconds). Thus, the default maximum of 5 farms per city generates 50 food per 30 seconds.
- Building a Granary adds +20% to food production of farms in the same City, increasing each farm's gather rate to 12 Food per 30 seconds within that City.
- Upgrading the Granary increases the gather rate per farm by +5/+10/+20. The upgrade affects all Granaries, although each Granary continues to only affect the food production of Farms in the same City.