Disambiguous This article is about the build rate of buildings. For the build rate of units, see Build Rate (Units).

Citizens are used to construct buildings, including wonders. In Rise of Nations, multiple citizens can construct a building simultaneously. However, each additional citizen is less effective. Thus, there is a tradeoff between how quickly a building is built versus the number of citizens taken from other tasks to help build it.

Build rate and number of CitizensEdit

The nth citizen simultaneously constructing a building will only contribute 1/n of the standard build rate. Thus, although each additional citizen will decrease the building time, it is generally inefficient to assign many citizens to construct the same building.

For example, suppose a building takes 1000 frames to build. This means that a single citizen will build it in 1000 frames. If two citizens are assigned to the building, then the building will take 1000/(1+1/2) = 667 frames to construct. If three citizens are assigned to the building, then the building will take 1000/(1+1/2+1/3) = 545 frames to construct. The build time, based on the number of citizens constructing the building, is as follows:

Number of Citizens Build rate Build time (%)
1 1 100
2 1.500 66.667
3 1.833 54.545
4 2.083 48
5 2.283 43.796
6 2.450 40.816
7 2.593 38.567
8 2.718 36.794
9 2.829 35.349
10 2.929 34.142
15 3.318 30.137
20 3.598 27.795
25 3.816 26.206
30 3.995 25.031
35 4.147 24.115
40 4.279 23.372
45 4.395 22.753
50 4.499 22.226

As a rule of thumb, 4 citizens will complete a building in half the time, 11 citizens will complete a building in 1/3 the time, and 30 citizens will complete a building in 1/4 the time. It would take 83 citizens to complete a building in 1/5 the time.

Modifiers to the build completion timeEdit

  • The construction line of upgrades at the Lumber Mill decreases the building time by 10% per upgrade. Thus, when this line is fully researched, a building only requires 70% of the original building time.
  • The Tobacco rare resource increases the current building progress by 10%.
  • The President Patriot increases the current building progress for buildings in his radius by 33%.

These modifiers take effect instantaneously and are multiplicative with each other and the above citizen building rate. For example, if The President moves near a building that is currently 60% complete, it will instantaneously increase to 80% complete. Thus, if you are building multiple wonders, you can move The President around to each wonder as they near completion; having The President nearby does not affect the actual citizen building rate, but only the current progress. A building might be increased to above 100% complete due to new modifiers being applied while it is being built, but it will not actually complete unless a citizen works on it.

Buildings under attack Edit

When a building under construction is attacked, the build rate is temporarily reduced to 1/4 of the normal build rate. The normal build rate resumes around 4 seconds after the building was last damaged. The damage will also reduce the completion progress somewhat. This does not include attrition damage, which damages the building under construction but does not affect the build rate nor its completion progress.