Armies

Units are grouped into armies, which are what moves and fights on the map. An army has a type, a stance, a status and, optionally, cargo.

Army types

Land
Support
Air
Naval
Amphibious

A unit can only be assigned to an army of a compatible type. Naval units can only be assigned to a fleet on a water node adjacent to the naval base that trained them.

Creating armies

Trained units auto-deploy, to the rally point if one is set (Set rally point on the district; Send all idle to rally moves idle armies there).
From the troops window, create an army, name it, assign or unassign units, and save an army as a template to recreate it later.
An army with units cannot be deleted: unassign them first.

Stances

Attack: engages any hostile army in range or on its node.
Defensive: never starts a fight, only fires back when attacked.
Passive: never fights, not even in retaliation (it can still take losses).

Statuses

Idle, Moving, Attacking, Defensive, In garrison.
An army carried aboard a transport cannot be ordered on its own.

Movement

Routes follow the node graph. Land armies use land nodes, fleets use water nodes, air armies fly over both within their air range.
A route is shortened at the last valid node when it would cross impassable terrain, hostile territory or exceed air range.
A move is blocked when the destination is incompatible terrain, hostile territory, beyond air range, or occupied by a foreign army, and refused when no route exists.
Terrain changes the cost of each edge (see Terrain); the research focus March Speed speeds armies up.
To cross water with land units, load them aboard a Naval Cargo or Plane Cargo; ghost infantry can also ride a Griffon or a Stealth Helicopter.

Garrisons and attacks

Armies on a district can garrison it as defenders, or attack it; the attack panel shows total attackers and defenders with their attack and defense.
Attacks can be scheduled with a delay in minutes so several armies strike together.
A battle ends with the district captured or held. The battle report lists surviving and destroyed units on each side, hard-countered units (which took extra losses and could not retaliate), and the spoils of war: resources and cargo looted, captured or destroyed, including ammunition.
Garrisoned districts also keep unrest down.