Mechanics
Spotters & forward observers
You never see the target. Everything the Iron Nest fires at is something somebody else looked at and described over a wire — which is why reading a spotter report correctly is most of the game.
A report is measured from the spotter, not from you
This is the single most common way a first firing solution goes wrong. When an observer calls a bearing, that angle is drawn from their grid square. Dial it straight onto the gun and you will traverse to a bearing that points somewhere else entirely. A report looks like this:
Alpha is Bearing 179° from Spotter#1 = G6 9:1 Alpha is Distance 5.61km from Spotter#2 = E8 1:3
Two facts about one target, each anchored to a different observer at a different grid. Your job is to convert them into one bearing and one range measured from the Nest.
Two bearings cross once. A bearing and a distance cross twice.
With two bearings the fix is unambiguous — the game's own tutorial line is “Mark both bearing angles, their intersection is the target.”
A bearing and a distance intersect twice. A line from one observer crosses a circle drawn around another at two points, and only one of them is the target. The game warns you about this directly. Resolve it with a third measurement, or by discarding the solution that sits behind your own lines.
The 0.5° margin, and when it starts to matter
Briefings state that spotter bearings are accurate to within 0.5°. On a normal fire mission that margin disappears inside the blast radius. It stops being harmless in two situations, both of which the game calls out before the mission that needs them:
- —When two bearings run near-parallel. Two lines crossing at a shallow angle move their intersection an enormous distance for half a degree of wobble. Prefer observers that see the target from widely different directions.
- —When measurements are chained. Fixing A from two spotters, then fixing B relative to A, stacks each error on the last. Cartagena is built around exactly this, and the briefing says so: errors compound with each link in the chain.
The console also reminds you to beware of bearing rounding errors — if a solution feels uncertain, the intended answer is to buy another observation rather than to fire and adjust.
Put the observer on the table, not just on the clipboard
The clipboard is a working surface. It gets wiped — deliberately, between fire missions, or by accident — and when it goes it takes the only copy of a report with it. Losing where Spotter#1 was standing after you have already spent the observation is the most expensive mistake on this page, because the position is not recoverable and the game will not re-issue it.
The map table is the durable record. Set a marker token down on the grid square an observer reports from and it stays there independently of anything on the clipboard — the settings menu treats the two as separate systems, with its own Delete Markers and Reset Marker Tokens controls. Plot each observer as its report arrives and clearing the clipboard costs you nothing.
A direction is an arc, not a point
Some reports hand you a heading with no range attached. That is a wedge of ground, not a target, and firing down the middle of it wastes the shell and the requisition. Search the arc instead: the Scout Plane photographs a stretch of ground along a bearing you pick, which is what turns a direction into a grid reference. If the ground looks empty because the target is concealed rather than distant, two shells do the job the eye cannot — TEAR reveals hidden units, and STAR lights the target area for scouting.
What each observation asset costs
Reports the bearing — and sometimes the distance — to the nearest enemy from where the observer stands.
Silent until an enemy battery fires, then reports the bearing that fire came from. This is how you find guns nobody can see.
Photographs a stretch of ground on a bearing you choose. The only asset that finds targets with no observer nearby.
Prices are per use from the requisition console. See requisition for what each kill pays toward them.
Enemy spotters work the same way — against you
An Enemy Spotter carries a 2-star threat rating for a reason. While one has eyes on the Nest, hostile batteries get the same quality of fix on you that your observers give you on them, and the console announces it plainly: enemy spotters found you, followed by incoming fire. When an unidentified battery keeps re-acquiring you after a relocation, the observer is the thing to kill, not the guns.
Work a real report through end to end in your first firing solution, or plot the observers directly in the firing solution planner.
Common questions
What is a spotter in IRON NEST?
A forward observer positioned somewhere on the map with eyes on the enemy. Spotters do not shoot. They report a target's bearing, and sometimes its distance, measured from where the spotter is standing — never from your gun.
How accurate are spotter bearings in IRON NEST?
Spotter bearings are accurate to within 0.5 degrees. The briefings note that this margin rarely matters on a single fire mission, but that it compounds when bearings run near-parallel or when a solution is chained through several measurements.
How do I find a target from two spotter bearings?
Plot each spotter at its own grid reference, draw its reported bearing as a line, and the point where the two lines cross is the target. The game states it plainly: mark both bearing angles, their intersection is the target.
I cleared my clipboard and lost where spotter 1 was. Can I get it back?
Not from the clipboard — but the map table is a separate record. Put a marker token down on the grid square a spotter reports from and it stays on the table no matter how many times the clipboard is wiped. The settings menu treats them as two different things, with its own Delete Markers and Reset Marker Tokens actions, so a position written only on the clipboard is a position you can erase by accident.
A report gives me a direction but no distance. What now?
A direction alone gives you an arc, not a point, so the next move is to search the arc rather than to fire down it. Fly the Scout Plane along that bearing to photograph the ground. If the target is concealed rather than merely unseen, a TEAR shell reveals hidden units and a STAR shell lights the area for scouting.
How much does a spotter cost in IRON NEST?
The Forward Observer punchcard costs 6 requisition and has unlimited uses. A Listening Post costs 1 and reports enemy artillery positions when they open fire, rather than spotting targets for you.