Lines

When you select a unit, it looks in adjacent rows for units of the same type that are In Line. Those units look in their other adjacent rows, and so on, until the chain stops. That group is a line. In Line is on The Map. Alternates count as the same type; see Units. Broken units are never part of a line. See Fatigue and Breaking.

If two units in the same adjacent row both qualify, the one whose center is closer is the one in the line.

Troop shooting line bonus stacks +20% per other eligible troop in the line, then multiplies by how Perfect that shooter is with its immediate adjacent-row neighbors: full strength in Perfect Line, nearly none at the edge of In Line, linear between (average of those neighbor overlaps). See Units, Damage, and The Map.

An order given to a unit is also given to the rest of its line. See Orders. The unit you touched is the selected unit. The others are subselected. A long press selects only that unit. Later orders stay on it alone until you give an order to a different unit. See Giving Orders.

Troop order passing is separate: an Advancing Troop that newly enters Perfect Line with a Halted or Reforming Troop on an adjacent row takes that order on itself alone. A long-press (solo) Advance while already In Line behind them does not re-inherit at Perfect Line, so that Troop can walk past. A normal line Advance still order-passes. It does not hand the order down the combat line. Perfect Line is on The Map. Order passing is on Orders.