Combat

Units fight on the ground and in orbit. Each unit has a role, and roles counter each other. Units that survive fights earn promotions.

Roles

Promotion	Tier	Requires	Effect
Drill	1	—	+3 defence.
Marksman	1	—	+3 attack.
Sapper	1	—	Movement costs 1 less, minimum 1; +30% damage against structures and city walls.
Pathfinder	1	MOV ≥ 3	+1 movement and +1 tactical sight; ignores zones of control from units at least two tiers lower.
Veteran	2	any tier-1	+15% maximum HP, rounded up; +3 healing per turn.
Shock	2	Marksman	+30% attack against a unit already damaged this turn.
Entrenched	2	Drill	Full fortification after one stationary turn; immune to the first bombardment each turn.
Void-hardened	2	any tier-1	No H=0 hostile-world combat penalty; +3 defence on Regolith, Basalt, Rime, Glacier, Serac, Crevasse, Ash or in orbit.
Logistician	3	any tier-2	No Logistics upkeep; Food upkeep halved, rounded down.
Loyal	3	any tier-2	Strain accrues on odd-numbered unpaid turns only; a Defect result becomes Desert.
Breakthrough	3	Shock or Sapper	May advance into a defeated defender's tile after a kill, retaining 1 movement point.
Commander	4	level 7	+2 attack and defence to friendly units on this and adjacent tiles; only the highest-XP Commander's aura applies.