OpenFront Population Growth and City Cap Guide

Direct answer: how does population growth work?

OpenFront does not split your population into workers and soldiers. The simulation stores Troops, Gold, territory, and structures.

The post-game Workers column is the label for fixed passive Gold income, not a population count that falls when you attack.

Your maximum Troops comes from a diminishing territory formula plus 250,000 for every completed City level. Current Troops then grow fastest with plenty of headroom and slow toward zero as the bar approaches that maximum.

Build or upgrade a City when the cap is restricting recovery or a planned reserve. Do not buy one merely because Troops are low. If you are far below the current cap, another City creates unused headroom without fixing combat losses.

The short rule is:

1. Read current Troops as a percentage of the current maximum.
2. Decide whether low Troops comes from cap pressure or from spending and losses.
3. Add City capacity only when the maximum is the real constraint.
4. Choose an upgrade for immediate capacity or a new City for another protected rail station.

The exact troop-cap formula

For a normal Human player, the current v0.33.7 code calculates:

maxTroops = 2 * (tiles^0.6 * 1,000 + 50,000)
          + 250,000 * sum(completed City levels)

Cities under construction do not count. A level-3 City contributes three levels, or 750,000 cap. Three level-1 Cities contribute the same cap.

The territory term uses an exponent of 0.6. More land always raises the cap, but each additional block of land adds less than the previous block.

Owned tiles	Cap without a City	Cap with one City level	Relative increase
1	102,000	352,000	+245%
100	about 131,697	about 381,697	+190%
1,000	about 226,191	about 476,191	+111%
10,000	about 602,377	about 852,377	+41.5%
50,000	about 1,419,507	about 1,669,507	+17.6%
100,000	about 2,100,000	about 2,350,000	+11.9%
200,000	about 3,131,433	about 3,381,433	+8.0%

The City bonus does not get smaller. Its absolute value stays 250,000 per level. Its percentage impact becomes smaller because a large empire already has a larger territory-based cap.

Bots and Nations use additional modifiers. A Bot receives one third of the base maximum. Nation difficulty multiplies it by 0.5 on Easy, 0.75 on Medium, 1 on Hard, and 1.25 on Impossible.

This guide uses the normal Human formula for player decisions.

The exact troop-growth formula

For a normal Human, the gain per simulation tick is:

growth = (10 + troops^0.73 / 4) * (1 - troops / maxTroops)

The game clamps the result so one tick cannot push Troops above the maximum. A normal tick is 100 milliseconds, so there are about 10 growth calculations per second.

The first term rises with current Troops. The final headroom term falls as the bar fills. Their combination creates a broad growth peak rather than a simple rule that lower is always faster.

For a Human with 10,000 tiles, no City, and a maximum near 602,377:

Current Troops	Share of cap	Gain per tick	Approximate gain per second
60,238	10%	703	7,032
150,594	25%	1,137	11,368
252,998	42%	1,281	12,812
301,189	50%	1,254	12,537
451,783	75%	842	8,419
542,139	90%	385	3,846
572,258	95%	200	2,000

The mathematical peak in this example is close to 42%. Treat that as a growth-efficiency signal, not a mandatory reserve target.

An exposed player at 42% can still be easy to attack. A player at 65% grows more slowly but has more force available immediately. The correct reserve depends on borders, alliances, terrain, and the next planned attack.

What Workers means in OpenFront

The current simulation has no independent worker quantity. Every living non-Bot player receives 100 Gold per tick before the lobby Gold multiplier. Bots receive 50.

The engine records that passive income in a statistics category named GOLD_INDEX_WORK. That is why the results table calls it Workers.

At the standard 10-tick cadence and a 1x multiplier, a Human receives about:

• 1,000 Gold per second;
• 60,000 Gold per minute;
• 125,000 Gold in about 2 minutes 5 seconds;
• 250,000 Gold in about 4 minutes 10 seconds.

Sending Troops, losing Troops, or raising the troop cap does not change this base rate. A City does not create more Workers and does not multiply passive Gold.

Trade Ships, Trains, conquest, captured trade, starting Gold, and lobby multipliers are separate sources. Use the Port vs Factory guide when Gold flow, rather than troop capacity, is the constraint.

City cost and capacity efficiency

City uses its own escalating level counter. It does not share that counter with Port or Factory.

next City level cost = min(1,000,000, 2^n * 125,000)

n is the effective number of City levels already owned and constructed by the player. A new City and an upgrade both advance the same counter by one.

Marginal City level	Cost	Added cap	Cap per Gold
1st	125,000	250,000	2.00
2nd	250,000	250,000	1.00
3rd	500,000	250,000	0.50
4th and later	1,000,000	250,000	0.25

There is no four-level hard cap in v0.33.7. The fourth total level reaches the 1,000,000 price ceiling; later levels remain upgradeable at that capped marginal price.

Do not call this a Gold return on investment. City converts liquid Gold into military capacity. Its return is faster recovery headroom, a larger reserve, and a possible Train station.

Build a new City or upgrade one?

Both choices add the same 250,000 cap and advance the same cost ladder. The difference is timing, position, and network value.

Upgrade an existing City when

• you need the cap immediately;
• the existing City is safely inside the core;
• another exposed structure would add capture risk;
• the rail network already has enough station locations.

The upgrade path raises the level immediately after the action passes its checks. It does not start another 20-tick construction timer.

Build a new City when

• you need a second protected Train stop;
• another station improves rail topology or redundancy;
• the old City is a concentrated nuclear target;
• the new site can survive its 20-tick construction period.

A City becomes a Train station only when a Factory is in range or a later Factory pulls it into the network. A City level does not increase Train stop payout or destination weight.

When cap is actually the bottleneck

Use three checks before spending Gold.

Check 1: are you repeatedly close to the maximum?

If the bar often sits above 80% during quiet periods, natural growth is heavily throttled. More land or another City level creates usable headroom.

If the bar rarely reaches 50%, the cap is probably not the immediate problem.

Check 2: would the next army use the extra capacity?

A City is strongest before a planned reserve, a contested chokepoint, or recovery from a large but successful expansion. It is weaker when no front or plan needs the additional Troops.

Capacity that remains empty for the entire match was expensive optionality.

Check 3: can the structure survive?

A captured City transfers its value to the occupier. Put population infrastructure behind a border that can hold.

If the core is under immediate pressure, the smallest effective defense can be more valuable than a larger maximum you cannot fill.

Three worked decisions

Scenario A: 10,000 tiles at 90% cap

Without a City, maximum Troops is about 602,377. At 90%, the player has about 542,139 and grows by roughly 3,846 per second.

One completed City level raises the maximum to about 852,377. Current Troops immediately become only 63.6% of the new cap, opening much more recovery room.

This is a strong City purchase if the site is safe and Gold is not needed for an urgent defense.

Scenario B: 10,000 tiles at 25% cap

The player has about 150,594 Troops and already gains roughly 11,368 per second. Another City raises the maximum but does not replace the army that was spent.

Pause optional attacks and rebuild first. Buy capacity later if the bar begins to bind.

Scenario C: a protected rail core

The player needs another 250,000 cap and already owns a Factory. Upgrading a City supplies capacity immediately. Building a new City supplies the same capacity after two seconds and adds another possible trade stop.

Choose the new City only if its station location and redundancy justify another structure on the map.

Population decisions during a match

Below 30% of cap

Preserve Troops and remove unnecessary attacks. Take only cheap land that improves the position. A new City usually does not solve this state.

Around 35% to 50%

Raw natural growth is efficient. Expand through safe, short actions while keeping enough reserve for visible enemies.

Around 50% to 70%

Growth is still useful and immediate defense is stronger. This is often a practical band before a planned fight or betrayal window.

Above 80%

The headroom factor is 0.2 or lower. If borders are safe, convert part of the reserve into useful land or raise the maximum with a protected City level.

Near 100%

Natural growth is almost stopped. Sitting full is correct only when you are waiting for a specific attack, deterrence moment, or coordinated team action.

Common population mistakes

Treating Workers as spare Troops

There is no worker slider or worker pool. Do not predict Gold income from the displayed troop bar.

Buying a City after every defeat

Low Troops and low maximum are different problems. A loss-driven shortage needs recovery and safer combat.

Believing City stops at level 4

The price stops doubling after the fourth total level. The upgrade capability does not stop.

Comparing only absolute cap

The same 250,000 is transformative on a small territory and a smaller percentage of a large empire. Compare the bonus with current maximum and planned reserve.

Building on the active border

Population capacity has value only while you own it. A cheap first City can become an expensive gift if the site falls.

Optimizing for 42% during danger

The growth peak does not account for an enemy attack. Keep more reserve when the tactical cost of being weak exceeds the lost growth rate.

Frequently asked questions

Does attacking reduce worker income?

No. Troop spending and passive worker-labeled Gold are separate calculations.

Does a City increase Gold income?

Not directly. It increases maximum Troops and may serve as a Train trade stop when connected to a Factory network.

How much cap does a City upgrade add?

Every completed level adds exactly 250,000 to the normal cap calculation.

Is level 4 the maximum City level?

No hard maximum appears in the v0.33.7 upgrade checks. The fourth total level is where the marginal price reaches its 1,000,000 cap.

Is a new City better than an upgrade?

Not for raw cap. Both add one level. A new City adds location and rail-network value; an upgrade is immediate and keeps the value concentrated in an existing safe structure.

Why does growth slow near a full bar?

The formula multiplies growth by 1 - troops / maxTroops. That factor approaches zero as current Troops approach the maximum.

Official sources and version boundary

This guide treats the formal v0.33.7 Release and tag as the live boundary.

The exact mechanics are in the official cap, growth, City cost, and passive Gold code and per-player tick execution.

City level and upgrade accounting confirms how completed levels enter the cap.

The Workers label is defined in the official statistics schema.

Its passive-income meaning is confirmed by the statistics implementation.

The site’s generated snapshot records extract checkout 0668045fa926eaa6d6995561a8e13fd8126895b6 and editorial series v33 separately. That checkout is reproducibility metadata, not the v0.33.7 tag.

For the next economic decision, compare Port and Factory. For a broader spending plan, read Economy Fundamentals.