Armor

Armor is the second layer of defense for most ships (after shields), absorbing damage that would otherwise be dealt to the hull. It is a mechanic that provides damage reduction based on multiple factors.

Summary

Despite the complete armor mechanics in Starsector being quite complex, the points that are actually important to understand as a player are quite simple, and can be summarized as such:

• Armor is a protective layer evenly distributed across the whole ship: Armor damage on one side of the ship might leave the armor in another part of the ship intact. That means it is preferable to focus your attacks on a single point in an enemy's armor, rather than only partially damaging large parts of it. Likewise, it is preferable to maneuver in a way that distributes armor damage you take across your ship, to keep the enemy from stripping off armor in one place entirely, exposing your hull.

• A small number of strong hits are a lot better at damaging armor than a large number of weak hits, even assuming all hits land in the same spot. A weapon's damage-per-shot(after damage modifiers) is just as important in judging its anti-armor effectiveness as the damage-per-second.

• Armor doesn't scale linearly, but in a way that ensures a flat armor bonus is useful regardless of the base armor stat. For example, adding the Heavy Armor hullmod (which increases armor by 300) to an Eagle-class cruiser (which has a base armor of 1000) actually increases overall armor effectiveness by about 70%, rather than expected 30%.

• Even after armor is completely destroyed, there is always "residual armor" equal to 5% of the base maximum armor value.

Detailed mechanics

Armor distribution

Armor status of the ship. Green cells represent intact armor and turn black as armor is damaged or destroyed. Note the 9 central cells surrounded by 12 cells pattern.

Armor is divided into cells distributed evenly around the ship. Each cell has an armor rating equal to 1/15th the ship's base armor rating. When armor is hit, the cell at the point of impact and 20 surrounding cells(see picture) add their armor values. The 9 inner cells contribute their full strength, while the outer 12 cells contribute half their strength. Note that all these cells add up to the base armor value of the ship, because $(9+{\frac {12}{2}})\times {\frac {1}{15}}=1$.

Visually, the width of each cell is 15 pixels for ships shorter than 150 pixels, 30 pixels for ships longer than 300 pixels, and 1/10th the ship length for ships in between. Hovewer for actual damage calculations the game uses an invisible enlarged rectangular grid which is not affected by size or shape of the ship. This means that armor is not any weaker on edges or parts that "stick out" even though cells there seem to not be fully surrounded.

Damage types

High explosive weapons do 200% damage to armor, energy weapons do 100% damage, kinetic weapons do 50% damage and fragmentation weapons do 25% damage. These damage type multipliers are applied before the armor damage reduction. EMP damage bypasses armor completely.

For the purposes of the armor damage reduction calculation, the damage done by beam weapons is equal to half the DPS of the sustained beam. For instance, a continuous beam weapon with 100 DPS suffers the same damage reduction from armor as an energy projectile weapon with 50 damage per shot. If the same beam were to fire in bursts lasting 0.1 seconds (with full strength for the duration of the burst), it would be treated as having 1000 DPS for this purpose, giving it the same armor damage reduction as a 500 damage energy projectile weapon.

Armor damage formula

Damage done to armor can be expressed as follows:

$armorDamageReduction={\frac {weaponDamage}{weaponDamage+armor}}$

$damageToArmor=armorDamageReduction\times weaponDamage$

where weaponDamage is the per-shot damage of the weapon, adjusted by Damage Types. Thus weapon damage equal to armor cuts the damage done by half.

The resulting armor damage is then distributed between the 21 armor cells that pooled their armor values. 9 "inner" armor cells take full damage and the 12 "outer" armor cells take only half the damage(because they contribute only half the armor to begin with).

This formula cannot reduce damage by more than 85% (equivalent to a minimum armorDamageReduction of 0.15). This can be improved to 90% (multiplier of 0.1) with the Polarized Armor skill).

Practical example

A Gauss Cannon (700 kinetic damage) shot hits a Fury (base armor 600):

$armorDamageReduction={\frac {350}{350+600}}=0.36$

$damageToArmor=0.36\times 350=126$

For comparison, a Hellbore Cannon (750 explosive damage) hit on the same Fury would instead deal (1500 / 1500 + 600) x 1500 = 1,071.4 armor damage, completely stripping armor from all 21 cells.

Residual armor

Even when completely destroyed, armor still provides 5% of its original maximum value for hull damage calculations. Damage type multipliers are still used for calculating the damage reduction from residual armor. See Hull article for details.

Change History

0.8a

• Armor value for damage reduction no longer goes below 5% of base armor value