40 CARROTCheck every model's local link
Each model must have at least one other model from its unit within 2 inches.
What is unit coherency in Warhammer 40K?
Coherency limits how far a unit can spread to screen, hold ground, or reach two places. The current check is not one number; it is a local link, one connected group, and a whole-unit envelope.
TL;DR
A coherent unit passes three checks: every model is within 2 inches of another model in its unit, all models form one connected group, and every model stays within 9 inches of every other model. Recheck after casualties. 40 Carrot warns when a formation breaks, but you still choose how the unit is arranged.
Why are there three coherency checks?
The 2-inch rule stops a model drifting off alone. The connected-group rule stops two separate clumps from passing just because each clump is tight. The 9-inch rule caps the total span, so a chain cannot stretch indefinitely.
Together they let a unit wrap an objective, screen a lane, or protect a character while remaining one formation. The legal shape can still be tactically fragile: casualties may remove the model that links two halves.
Check the formation in this order
Local links first, whole group second, outer envelope third, then repeat after any removal.
Check the whole unit is connected
Follow those 2-inch links across the unit. Two separate clumps are not coherent even when each clump works on its own.
Check the 9-inch envelope
Every model must remain within 9 inches of every other model in the unit.
Remove casualties and check again
Recheck all three conditions after models are removed, because a legal screen can break when a linking model disappears.
Move the formation and watch the gap open
This published movement frame lets you test true-scale spacing. In the full app, a unit that fails the current 2D check is marked “BREAKING COHERENCY” so the mistake is visible before you use the position as a practice reference.
How much stretch can the tactic afford?
A ten-model squad at its limit may touch ground, block a lane, and protect a character at once. Every extra inch also makes the formation more sensitive to a casualty. If one model is doing all the linking work, identify it before the opponent does.
40 Carrot offers Line/Coherency, Base-to-base, Circle, and rank arrangements. Those presets keep legal margins when the models physically fit, but they do not choose the right formation for the mission. Dead models and passengers off the battlefield are excluded from the check.
Formation check
- Local
- Every model has another model from the unit within 2 inches.
- Connected
- Every model can be reached through one chain of legal links.
- Envelope
- No model is more than 9 inches from any other model in the unit.
- Casualty
- The formation remains legal after the most likely linking model is removed.
Build the screen at true scale
Practise legal spacing →Unit placement, formation tools, coherency warnings, and measurement are free.
Frequently asked questions
What is unit coherency in Warhammer 40K?
Coherency is the spacing rule that keeps a unit fighting as one group: each model must stay within 2 inches of at least one other model in the unit, the unit must form one linked group with no clumps separated by more than 2 inches, and every model must stay within 9 inches of every other model in the unit.
How far apart can models in a unit be in 11th Edition?
Each model needs another model of its unit within 2 inches, and no model may be more than 9 inches from any other model in the unit, so a unit can chain out, but only inside the 9-inch envelope.
Can a unit split into two groups?
No. The unit must form one linked group: two clumps separated by more than 2 inches break coherency even if each clump is internally legal.
Does 40 Carrot move an incoherent unit automatically?
No. 40 Carrot can warn that a unit is breaking coherency and offers formation tools, but it does not silently move your models or choose the tactical shape for you.