Ground Combat Sequence

Ground combat is triggered when attacking a target planet via Pillars.

Combat involves:

• land units sent in the assault;
• the Small Transporter and Large Transporter sent with the assault.

A ground attack cannot be launched if it contains no military assault unit. Carriers alone can accompany an assault, but do not start combat on their own.

Before the simulation, the target planet is resolved using only its exposed resources, so resources protected by the sanctuary cannot be looted.

Example

An assault made up only of carriers is rejected before the attack mission is created.

A ground attack can be militarily victorious without being able to loot all recent production if the target planet has been inactive for less than 8 hours and part of its natural production is still protected by the sanctuary.

Only land units in the military category fight directly.

Attacking side:

• land military units fight;
• carriers accompany the assault, but do not fire;
• logistics and civilian units do not participate in combat.

Defending side:

• only land units in the military category participate;
• logistics and civilian units present on the planet are not included in the simulation.

Example

Sending scientists or pilots in a Pillars attack does not turn them into combatants. They do not take part in resolving the ground battle.

Ground combat lasts a maximum of 10 combat turns.

Each turn:

1. shields are recalculated with a 10% degradation, down to the 50% threshold;
2. the game calculates the number of shots fired by both sides;
3. the attacker and defender resolve their shots against surviving units;
4. losses for the turn are recorded;
5. combat stops if one side has no military units left.

The mission launch requirements are described in Starting Ground Combat. How the Iris blocks an attack before combat is explained in Ground Interception by the Iris. The consequences for neutralized units, including wounds and captures, are detailed in Wounds and Captures.

Ground combat does not resolve shots one at a time against a random target. Instead, it distributes shots statistically among opposing groups, using a targeting weight and possible coverage.

For each group:

• the number of shots is unit count × rate of fire;
• if a unit has no defined rate of fire, it fires 1 time per turn;
• nominal shots are distributed according to unit count × targeting weight;
• rounding remainders are redistributed deterministically to preserve the total number of shots;
• Soldiers and Iron Ramparts have a targeting weight of 1, Rift Specters have 2, Kinetic Reapers have 3, and Plasma Superchargers have 4;
• each stack of Kinetic Reapers multiplies the targeting weight of Soldiers by 6, without receiving a damage bonus;
• if a Reaper volley over-targets the last Soldiers, its excess shots are not transferred to another category;
• Iron Ramparts can cover shots aimed at units that cannot provide cover, up to 10 shots per Iron Rampart per turn;
• if coverage is saturated, the remaining shots stay on their nominal target;
• each hit can put at most one unit out of action.

How should CIB and PRI be read?

• CIB is the targeting weight a group receives: it comes into play when the enemy distributes its shots among your groups;
• PRI is a target preference specific to the firing unit.

For the Kinetic Reaper, PRI 6 means it is six times as likely to choose Soldiers as it would be with normal targeting. This priority guides its shots but does not increase its damage.

This means that in ground combat, targeting is distributed according to unit counts and unit profiles, rather than selected completely at random shot by shot as in space. Coverage is applied before evasion: a shot redirected to an Iron Rampart uses the Iron Rampart's evasion and defenses, even if the unit originally targeted would have had better evasion. Excess damage from a hit is not redistributed to another target: it becomes overkill, even if the target had already received enough attack to be put out of action.

Example

If a defender fields two groups with the same targeting weight, one representing 80% of the forces and the other 20%, the larger group will receive most of the shots calculated for that turn. A smaller group with a higher targeting weight may still receive more shots than a simple calculation based on unit count would suggest. If the attacker scores 300 000 effective hits during the turn, it cannot put more than 300 000 units out of action during that turn, even if some hits deal much more damage than a unit's HP.

Shields are recalculated at the start of each turn down to the 50% threshold, then the remaining shield becomes persistent.

Through turn 6, the shield is reset to a value reduced from its base value:

• turn 1: 100%
• turn 2: 90%
• turn 3: 80%
• turn 4: 70%
• turn 5: 60%
• turn 6: 50%
• turns 7 to 10: no further recalculation; the shield remaining after the previous turn is kept, capped at 50% of the units still active

Damage always hits the shield first. If the shield is insufficient, the surplus is applied to hit points.

Example

A unit with 1 000 shield points starts at 900 again on turn 2, then at 800 on turn 3. From turn 7 onward, if it has only 120 shield points remaining, it keeps those 120 points instead of rising to a new value.

If the attacker has no military units left, the attacker loses the combat.

A resolved combat has two possible outcomes:

• if the attacker loses all military units during combat, the defender wins at the end of the turn in question;
• if both the attacker and defender are wiped out, the result is a draw.

Attacks rejected before combat are covered under the launch requirements.

If the defender wins:

• the attacker loots no resources;
• details about unit wounds and captures are covered in Wounds and Captures;
• the rules for carriers are detailed in Carriers and Losses;
• surviving units depart on a return mission, if any remain (see Return Composition).

Example

If you attack with soldiers but they are all eliminated on turn 3, the defender wins at the end of that turn.

If both sides lose all their units in the same turn, the combat ends in a draw.