Troop Cap and the 42.2% Rule

Hoarding troops is the single most common mistake in OpenFront, and the reason is buried in two lines of the game’s config file. Here is what those lines say.

The short version

• Troop growth peaks when you sit at 42.2% of your cap
• Near the cap, growth is close to zero
• So the correct loop is: attack, drop back to ~40%, refill, attack again
• The +troops/s readout turns orange the moment you pass the peak — that is your cue to attack

The troop cap formula

maxTroops = 2 × (tiles^0.6 × 1000 + 50,000)
          + (sum of city levels) × 250,000

The two terms behave very differently.

Land scales at ^0.6, so it has diminishing returns. Quadrupling your tiles raises the cap by only about 1.7×.

Cities are linear at +250,000 per level. The tenth city level gives exactly as much as the first.

Situation	Max troops	Reading
49 tiles (right after spawn)	~120,700	Starting value
1,000 tiles	~226,000	Land alone barely doubles it
1,000 tiles + one level-1 city	~476,000	One city beats 1,000 tiles
4,000 tiles	~390,000	4× the land, 1.7× the cap

A “+25,000 per city” figure circulates in some community writeups. The actual code says +250,000 — a factor of ten.

Where 42.2% comes from

Troops gained per tick (one tick = 100 ms):

gain = (10 + troops^0.73 / 4) × (1 − troops / maxTroops)

The first term grows with your troop count; the second collapses toward zero as you approach the cap. Solving for the balance point:

d/dr [ r^0.73 × (1−r) ] = 0
→ 0.73 × (1−r) = r
→ r = 0.73 / 1.73 = 0.4220…

That derivative is the origin of the “42%” number the community passes around as folklore.

Using it in a real game

Peacetime band is 35–55%. Below 30% you cannot defend; above 60% you are throwing away growth.

Only fill to 70–80% when you are staging a single decisive push.

The first minute is an exception. Early expansion raises the cap, and the larger cap compounds into more growth, so openers should sit lower — around 20–30% — and spend more aggressively. See the 1-minute build order once it is published.

The color tells you

The +troops/s indicator in the control panel is green while the growth rate is still rising and orange once it starts falling.

Orange means you just crossed 42.2%. No math required — when it turns orange, click.

Common mistakes

1. Hoarding troops. At the cap, your growth engine is switched off.
2. Taking land and never building cities. You cannot out-expand the ^0.6 curve.
3. Placing cities on the border. Buildings transfer with the territory — build them deep inland.
4. Pushing the attack slider to 100%. Past a 2:1 troop advantage, extra troops buy you nothing.