Component Damage

Each Component inside a ship has its own health pool. When armor has been penetrated, damage is dealt to components depending on direction of hit and the component's position in the ship.

Damage Mechanics

Most attacks will cast some kind of ray or sphere colliders (aka hitboxes) through the ship (some attacks even cast multiple colliders). This collider will damage components, though the specifics vary depending on damage type

Components that are damaged below 0 HP will be destroyed (greyed out), and cannot be repaired unless a restore is used. However, there are two exceptions: Damage Threshold, and (Reinforced).

Damage Threshold

In order to destroy a component, the final "killing" hit has to deal more damage than the Damage Threshold (DT). If not, the component is brought down to 0 HP and disabled (shows as red), but is not destroyed, and therefore can be repaired without needing restores. This is checked after Damage Reduction (DR) is applied, which can make DT much more effective on ships with high DR.

Reinforced

A reinforced component can only be killed once it's at 0 HP. Any hit when the component is above 0 HP will only bring it down to 0 HP This means that a reinforced component with a DC team repairing it must be hit twice within the 0.25 second window between repair ticks or else the DC team will bring the component above 0 HP (Note that DC teams inside nearly destroyed modules are very vulnerable to damage and can be killed quickly)

The two hits do not have to be the same; any hit that brings the component down to 0 HP will count for the first hit, regardless of how little damage it deals or if it beats the component's DT. However, the second "greying" hit will have to beat DT as usual

Note that the reinforced tag is only "stripped" in the next frame, two hits in the same frame will both be resisted by reinforced, but if the second hit is spaced a moment afterwards, it will break through as expected.

Damage Reduction

A Hull's Damage Reduction stat reduces incoming damage by the percentage shown. For example, 40% DR will reduce 100 damage to 60 damage.

This modifier applies before damage threshold checks, and therefore massively amplifies the protective effect of Damage Threshold, especially against smaller munitions.

DR begins increasing once 20% of the component slots are filled, and maximizes when 60% of the component slots are filled. Slot size does not matter, only the number of slots filled. Damage Reduction does not change as modules are destroyed.

Damage reduction does not affect fire, bshort, or burnthrough damage. Some weapons ignore DR.

Interior Density and Penetration Depth

Just like real life ships, all ships in Nebulous also have internal structural bulkheads to provide redundancy against threats in space. In game, internal hull structure is generalized as a homogeneous interior density (Interior Armor Density Equivalent) measured in cm of armor per meter, with different hull classes having different densities. Interior density is used to determine penetration depth of certain damage types. For example, if HEKP hits a Solomon and has 180cm of pen left over after penetrating armor, the Solomon's 1.2cm/m density means the penetrator can go up to 150 meters into the hull.

Interior Armor Density Equivalent of the Hulls

ANS Hull	Interior Density (cm/m)	Size (Length/Width/Height)	Total Armor Equivalent (Front/Side/Top)	Internal Armor Equivalent (F/S/T)
Sprinter	0.5	80/37/28m	56/35/30cm	40/19/14cm
Raines	0.5	96/35/40m	78/48/50cm	48/18/20cm
Keystone	0.5	130/50/45m	109/69/67cm	65/25/23cm
Vauxhall	1.00	215/62/60m	275/122/120cm	215/62/60cm
Axford	1.20	195/70/75m	314/164/170cm	234/84/90cm
Solomon	1.20	285/80/105m	458/212/242cm	342/96/126cm
OSP Hull	Interior Density (cm/m)	Size (L/W/H)	Total Armor Equivalent (F/S/T)	Internal Armor Equivalent (F/S/T)
Ferryman	0.5	68/36/23m	44/28/22cm	34/18/12cm
Draugr	0.5	87/53/40m	54/37/30cm	44/27/20cm
Flathead	0.5	128/56/52m	160/124/122cm	64/28/26cm
Ocello	1.2	210/50/75m	312/120/150cm	252/60/90cm
Marauder	0.25	309/90/115m	118/63/69cm	78/23/29cm
Moorline	0.25	345/100/110m	127/65/68cm	87/25/28cm

Most damage types have a minimum pendepth of 15m. Even if the leftover penetration is 0cm, as long as it penetrates armor it will penetrate to 15m deep

Some damage types have guaranteed penetration depth; In this case they ignore all penetration depth (pendepth) mechanics (except in some cases for calculating overpenetration) and will always penetrate up to their guaranteed pendepth.

Note that some damage types have conditions that can stop the attack early, even if it would normally penetrate deeper.

Overpenetration

If a shell penetrates armor and does not stop inside the hull due to fuzing, internal density, or armor at the exit point, the shell overpenetrates (overpens) and does reduced damage against the ship (determined by the shell's overpenetration modifier). Most shell types also have reduced damage and different damage behaviors when overpenetrating

In some cases, the overpenetration vfx will play, but the shell will not exit the ship. In this case the hit is still treated as an overpenetrating hit even if the shell doesn't visibly exit.

Structure break

Structure boxes of the different hulls. Diagram by PuppyFromHell

All ships have a "Structure hitbox". if an attack hits this hitbox, and does not damage any components, the damage is dealt to the structure. Once enough damage has been dealt to the structure, the ship becomes structure broken, and any more damage to the structure is dealt to a random component instead. In this state, crew also take 50% more damage

Damage Type Overviews

Behavior of AP and HE shells as they penetrate an Axford. Not to scale. Diagram by smolcake.

HE (Shell)

HE shells create an explosion (sphere) inside the ship at a point along their path of travel. Any components that touch this sphere are damaged. The damage of the round is spread between all components equally. For example, a 150 damage shell will do 30 damage to 5 components or 75 damage to 2 components. If they overpen, the round does not create an explosion and the reduced damage is spread equally among all components that the round intersected with.

The explosion position is determined by the pendepth and the penetration envelope stat. Most HE shells have a penetration envelope of 0.8, which means they will detonate at some point between 80% and 100% of their pendepth.

AP (Shell)

AP shells damage the first non-destroyed component in their path. If they overpen, the reduced damage is spread equally among all components that the round intersected with.

AP Sabot (Rail)

AP Sabot always spreads their damage across all components hit, dealing a certain fraction of damage to each component that falls off for each component hit, depending on the overpen multiplier. This applies even if the shot overpens.

e.g, a 300mm AP Rail Sabot with 80 damage and 50% overpen multiplier will deal 40 damage to the first component, 20 damage to the second, 10 damage to the third, etc

AP Sabot will always cause a critical event (crit) in a random component if they hit the structure hitbox, even if the ship is not structure-broken.

AP Sabot will never trigger catastrophic events (but the subsequent fires can cause catastrophics)

RPF (Shell)

RPF shells fire multiple shrapnel shards in a tight cone towards the nearest target (simulating the few shards that would potentially threaten the target, out of the dozens of fragments). These shards act like AP shells, and total up to the listed damage (eg, 250 RPF deals 16 damage per fragment, for a total of 128 damage).

Most RPF shells ignore normal penetration depth mechanics; if the fragments penetrate armor, they will always penetrate a certain depth into the hull regardless of interior density or leftover penetration.

Missiles within the blast radius of RPF shells have a 50% chance of being damaged (20 damage, 1.0cm pen for 120mm RPF; 30 damage, 2.0cm pen for 250mm RPF)

RPF will trigger on terrain.

Bomb (Shell)

600mm bomb shells emit 12 fragments per target, each dealing 40 damage. The listed damage for 600mm Bomb shells assumes it hits 5 targets.

Bomb shells hit all ships within their blast radius (500m radius for 600mm bomb shells) with multiple fragments. These fragments are distributed randomly across the target's bounding radius. Or in other words, if you imagine a circle that circumscribes the ship, the 12 fragments fired at that ship will be distributed randomly inside that circle.

This can result in some fragments missing the ship, e.g. 600mm bomb shells will not always score 12 hits on every ship in its radius as ships do not fully encompass their bounding radius. In addition, these fragments can strike other targets inside the blast radius besides their intended target.

Bomb shells explode with a timed fuze. When firing on tracks, that timed fuze is stepped back by 0.5 seconds and will randomly vary ±0.33 seconds

Missiles within 300m of a bomb shell explosion have a 50% chance of being damaged for 30 damage, 2.0cm pen

Plasma

Plasma splits its damage across all components in its blast radius.

In addition to the main hit, plasma hits will also splash into 8 more splashrays upon impact, which array themselves in an approximate ring 7.5m away from the main impact location. These splashrays each have the same armor shredding and radius as the main hit, but deal no internal damage. Splashrays each shred armor separately, and can overlap in rare cases

Plasma armor shredding ignores armor angle, and shredding falls off over distance.

Beam

Beams deal damage five times a second, and therefore their damage per hit is 1/5 of the listed damage per second. Beams damage the first component in their path, have a fixed penetration depth of 150m (width of 6.66m), and cannot overpenetrate.

Beams deal reduced damage and armor penetration at longer ranges, down to 95% at half of max range, and 50% at max range.

see also: Puppy's beam damage tool

HEI (Missile)

Diagram of the behavior of HEI and HEKP warheads on an Axford. Not to scale. By smolcake.

HEI splits its damage into multiple fragments (aka rays), each dealing 50 dmg. The amount of fragments totals up to the listed damage value. e.g. a missile that has a listed damage of 1440 will split its damage into 28 fragments dealing 50 dmg, with one fragment left over dealing 40 dmg.

These fragments spray out in a 35 deg cone pattern from the impact location (note that the cone angles given on this page use internal values, and are therefore only half of the full angle). Each fragment splits their damage among all components in a 70m line (ignores pendepth mechanics), and do not overpenetrate. (e.g. the damage ray hitting two components will deal 25 damage to each, hitting three components will deal ~17 damage to each)

For missiles, HE armor shredding radius gradually increases as warhead size increases. It starts at ~3.5m, goes to 5m at 1500 damage, 8m at 5000 damage.

Rockets function similarly, but with a slightly wider 45 deg cone and a variable ray length from 40m to 60m

HEI warheads ignore armor angling.

HEI (Mine)

Works similarly to standard HEI, but the fragments deal 100 damage instead (times 50, for 5000 damage in total), with 100m-150m long rays, in a 50 degree cone.

Mass driver/Fracturing block

OSP Fracturing blocks have a similar damage type compared to HEI, but instead deal only 15 damage per fragment, times 20 fragments, in a 35 deg cone. Fracturing block rays are emitted from the impact location, length of the rays is determined by penetration depth of the attack (for 500mm fracturing blocks, this is capped at 30m and has no penetration depth override). Fracturing block damage rays ignore damage reduction.

Fracturing blocks can visually overpenetrate, but this only allows the block to pass through the ship; overpenetration does not change the damage type of fracturing blocks and does not reduce the damage. Overpenetrating fracturing blocks will still deal the same damage and emit the same amount of rays on impact. As a side effect, the block itself also loses no damage after overpenning, which means if it hits a second target and penetrates, that target will also take full damage.

Unlike missile HEI, Mass drivers are affected by armor angling.

HE-SH (Shell)

600mm HE-SH works similarly to fracturing blocks. It applies 7× 60 damage rays, 50m maximum ray length, 15 deg cone. HE-SH cannot overpenetrate hulls.

HEKP (Missile)

Minimum armor penetration that guarantees HEKP will hit 171.6m penetration depth against a given hull class, assuming their armor is at the maximum possible angle and is fresh.

ANS Hull	Armor	Internal Density (cm/m)	HEKP Pen
Sprinter	8cm	0.50	106cm
Raines	15cm	0.50	124cm
Keystone	22cm	0.50	141cm
Vauxhall	30cm	1.00	247cm
Axford	40cm	1.20	306cm
Solomon	58cm	1.20	351cm
OSP Hull	Armor	Internal Density (cm/m)	HEKP Pen
Ferryman	5cm	0.50	99cm
Draugr	5cm	0.50	99cm
Flathead	48cm	0.50	206cm
Ocello	30cm	1.20	281cm
Marauder	20cm	0.25	93cm
Moorline	20cm	0.25	93cm

The HEKP penetrator is a spherical hitbox 10m wide and hits all components in a straight line up to 175m from the impact location. It spreads its listed damage equally among all hit components. The penetrator has a 2.0m armor shredding radius

The HEKP explosive creates a line of explosions along the path of the penetrator, and deals more overall damage as penetration depth increases, up to its listed maximum damage at 175m. HEKP does not suffer an explicit overpen penalty, but smaller hulls may not be large enough to allow the HEKP penetrator to travel 175m for maximum damage.

To be specific, the HEKP Explosive splits its damage among 26 explosions. It tries to drop one explosion exactly every 6.6m (up to the maximum depth of 175m). If the explosive cannot drop all 26 explosions (either because the ship's hull is thinner than 175m, or the Penetrator did not travel 175m), then the damage in those explosions are lost. However, the total explosion damage will never go below 40%; The remaining explosions will have their damage scaled up to meet the 40% minimum.

Explosion count is rounded down; HEKP will create no explosions below 6.6m (but the penetrator can still damage components)

HEKP explosion radius varies throughout the explosion chain, peaking at ~25m radius at the 18th/19th explosion (~119m deep) and dropping off to ~7.5m radius near the beginning and end. Damage per explosion is the same for each explosion. Damage per explosion is distributed between components similarly to an HE shell. Armor shredding radius scales in a similar way, peaking at 6.0m (12m across in best case) and dropping off to ~1.8m at the beginning and end. This is measured from the explosion point, not from the nearest surface

While the explosion damage and armor shredding value scales with warhead size, the shredding and damage radius are fixed regardless of warhead size

Blast Frag (Missile)

Chance to hit based on angle of intercept.

Type	Head-On	Side	Back
BF	50%	20%	80%
BF-EL	85%	65%	95%

Blast Frag detonates on the first enemy that comes within fuze range (regardless if it's the current target or not), and has a chance of hitting against all missiles in its AoE. The fuze range is equal to the blast radius, with an upper limit of 50m

Each missile within range of a blast frag detonation only has a chance of actually being hit depending on the angle of intercept. This is calculated using the dot product between the normalized velocity vectors of the two missiles. Or, in simpler words, it depends on the direction the missiles are moving in. Moving toward each other is head-on, moving parallel to each other is chase

Blast Frag will trigger on ships, but does not damage ships whatsoever, and will show up as a "miss" if it triggers on a ship.

Blast Frag will trigger on terrain.

External Links

• Puppy's damage mechanics tool - visualizes various hull damage mechanics (such as an armor penetration, beam damage falloff over distance with varying amounts of Focused Particle Accelerators)
• Puppy's All-in-one Calculator - contains raw data on a variety of mechanics in Nebulous (Such as blast frag hit chances, flak AoE multipliers, HEKP explosion multiplers, etc)