Example: Designing a Missile Destroyer

Updated: v2026.01.30

This worked example walks through designing a 6,000-ton missile destroyer optimized for long-range anti-ship strikes. We cover launcher selection, missile design, fire control configuration, magazine sizing, and point defense – showing the reasoning and math behind every decision.

Objective

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Design a 6,000-ton missile destroyer capable of:

  • Engaging hostile warships at long range (4,000,000+ km) with anti-ship missiles
  • Carrying enough ordnance for sustained engagements (30+ missile salvo capacity)
  • Defending itself against incoming missile fire with point defense
  • Operating as part of a destroyer flotilla (4-6 ships in a task group)

Starting Conditions

Updated: v2026.01.30

  • TN Start: Nuclear Thermal Engine technology (5 EP/HS), Pressurised Water Reactor
  • Missile Technology: Size-1 launchers available, Magneto-Plasma engine (4x fuel efficiency)
  • Warhead: Strength-4 warheads (4 damage per MSP of warhead)
  • Missile Hit Chance: v2.2.0+ speed ratio system (agility removed from PD calculations) \hyperlink{ref-ex-mdd-1}{[1]}
  • Active Missile Sensor: Resolution-1 available (smallest warships), strength 10
  • Fire Control: Missile FC with base range and tracking
  • Shipyard: Naval yard capable of 6,000 tons

Step 1: Missile Launcher Selection

Updated: v2026.01.30

The launcher size determines our missile size, which cascades into every other design decision. Key trade-offs:

Launcher Size (HS) Missile Size (MSP) Reload Rate Launcher Mass
1 HS 1 MSP 30 sec base 50 tons
2 HS 2 MSP 30 sec base 100 tons
3 HS 3 MSP 30 sec base 150 tons
4 HS 4 MSP 30 sec base 200 tons

Larger missiles carry more warhead, fuel, and sensor – but fewer fit on a small destroyer. For a 6,000-ton hull, we want the best balance of firepower per ton.

Decision: Size-2 launchers (2 MSP missiles)

Rationale:

  • Size-1 missiles are too small for meaningful warhead + seeker + fuel
  • Size-3 and Size-4 launchers consume too much tonnage on a destroyer
  • Size-2 gives us a 2 MSP missile budget – enough for a balanced anti-ship missile

Tip: Size-1 missiles excel as point defense interceptors and area-denial weapons. Save them for dedicated PD platforms. Your anti-ship missiles should be at least size-2 for adequate range and damage.

Step 2: Anti-Ship Missile Design

Updated: v2026.01.30

With 2 MSP of missile space, we must allocate between four components:

  1. Warhead – damage on impact
  2. Engine – speed (affects time-to-target and hit chance via speed ratio; see Step 4)
  3. Fuel – range at the given speed
  4. Seeker – terminal guidance (active sensor to acquire target)

Component Budget (2 MSP Total) 

Warhead:  0.4 MSP  -- Damage = 0.4 * 4 (warhead tech) = 1.6 damage per missile
Engine:   0.8 MSP  -- Speed (determines hit chance in v2.2.0+)
Fuel:     0.5 MSP  -- Range
Seeker:   0.3 MSP  -- Terminal guidance sensor
------
Total:    2.0 MSP

Warhead Analysis

At Strength-4 technology:

Warhead damage = Warhead_MSP * Warhead_Strength
               = 0.4 * 4 = 1.6 damage per missile

A single missile does 1.6 damage – modest, but we are firing salvos of 8-12. Per salvo:

Salvo damage = 8 missiles * 1.6 damage = 12.8 damage
             = 12 missiles * 1.6 damage = 19.2 damage

Against a ship with 3 layers of Duranium armor (15 strength per column), a 12-missile salvo concentrating on a few columns will penetrate armor and damage internals.

Engine Analysis

With Magneto-Plasma drive (4x fuel efficiency multiplier) and 0.8 MSP engine:

Missile speed = Engine_MSP * Engine_Power_Per_MSP * 1000 / Missile_Size
             = 0.8 * 12 * 1000 / 2
             = 4,800 km/s (estimated at starting engine tech)

Point defense hit chance (v2.2.0+) depends on the speed ratio between PD tracking and missile speed \hyperlink{ref-ex-mdd-1}{[1]}:

Base_Hit_Chance = 0.1 * (Missile_Speed / Target_Speed) -- for missile-vs-ship
PD_Hit_Chance = min(1.0, FC_Tracking / Missile_Speed) -- for PD vs incoming missile

At 4,800 km/s against a CIWS tracking at 5,000 km/s:

PD_Hit_Chance = min(1.0, 5,000 / 4,800) = 1.0 (fully tracked)

This means our missile is vulnerable to base-level CIWS. Faster missiles (higher speed) reduce PD hit chance.

Tip: In v2.2.0+, missile speed is the primary factor in surviving point defense. Faster missiles reduce the PD tracking ratio, making them harder to intercept. Always prioritize engine allocation in missile design.

Fuel Analysis

With 0.5 MSP fuel and Magneto-Plasma efficiency:

Fuel capacity = 0.5 * 2,500 litres (base per MSP) = 1,250 litres (estimated)
Range = Fuel / (Consumption_Rate) * Speed

At 4,800 km/s with efficient engines, estimated range: approximately 60 million km (60 Mkm). This provides engagement capability well beyond beam weapon range.

Seeker Analysis

The active missile sensor at 0.3 MSP with Resolution-1, Strength-10:

Detection range = sqrt(Sensor_Strength * 0.3 * Target_HS) * 10,000 km

Against a 10,000-ton target (200 HS):

Detection = sqrt(3.0 * 200) * 10,000 = sqrt(600) * 10,000
          = 24.5 * 10,000 = 245,000 km

This is the missile’s terminal acquisition range – the distance at which its onboard sensor locks onto the target. The missile uses fire control guidance until it reaches this envelope, then switches to self-guidance.

Final Missile Specification 

ASM-2 "Javelin" Anti-Ship Missile
  Size: 2 MSP
  Speed: ~4,800 km/s
  Range: ~60 Mkm
  Damage: 1.6 per missile
  Hit Chance vs 4,000 km/s target: 0.1 * (4,800/4,000) = 12%
  PD vulnerability: CIWS at 5,000 km/s tracking = 100% hit chance
  Seeker: Active, 245,000 km acquisition vs 10,000-ton target
  Cost: ~2 BP per missile

Step 3: Fire Control Configuration

Updated: v2026.01.30

Missile fire controls determine how many missiles can be guided simultaneously and at what range they can be launched.

FC Requirements 

Missile FC Parameters:
  Range: Must exceed missile range (60+ Mkm)
  Resolution: Match expected target size
  Tracking Speed: Not critical for missile FC (missiles self-guide at terminal)

Decision: 2x Missile Fire Controls at 4 HS each (200 tons each)

Each FC can guide one salvo at a time. With 2 FCs:

  • Fire first salvo on FC-1
  • Fire second salvo on FC-2 while FC-1 guides first salvo
  • By the time salvo 1 hits (or misses), FC-1 is free for salvo 3

This provides continuous fire capability without guidance gaps.

FC allocation: 2x 4 HS = 8 HS = 400 tons total

Tip: Always carry at least 2 missile FCs on any dedicated missile ship. A single FC means you cannot fire again until the first salvo resolves – a potentially fatal delay if the first salvo misses or the target has friends.

Step 4: Launcher Count and Magazine Sizing

Updated: v2026.01.30

Launcher Count

With size-2 launchers (2 HS = 100 tons each), how many can we fit?

Target: 8-missile salvos (a good balance between concentration and ammunition conservation)

Decision: 8x Size-2 Missile Launchers

Launcher tonnage: 8 * 100 = 800 tons (16 HS)

Eight launchers fire a full salvo every reload cycle. With base 30-second reload (reduced by technology), this gives sustained fire rate of one salvo per 30 seconds.

Magazine Sizing

Each magazine holds missiles for reloading. We want enough for a sustained engagement:

Engagement scenario: 4-6 salvos before needing to withdraw for resupply
Missiles per salvo: 8
Total missiles needed: 8 * 5 = 40 missiles minimum

Magazine capacity at Size-2 missiles \hyperlink{ref-ex-mdd-2}{[2]}:
  Each magazine HS holds: ~17-18 MSP capacity
  Missiles per HS = 17 / 2 = ~8-9 missiles per HS

Target: 40 missiles
Magazine size needed: 40 / 8.5 = ~4.7 HS (round up to 5 HS = 250 tons)

Decision: 2x Magazine (3 HS each = 150 tons each, 300 tons total)

This provides approximately 51 missiles (approximately 6 full salvos plus spares). The two magazines provide redundancy – if one is hit and explodes, half the ammunition survives.

Tip: Magazine explosions are catastrophic. When a magazine is hit and detonates, ALL missiles inside contribute their warhead damage to your own ship. Two small magazines are always safer than one large magazine, even if slightly less tonnage-efficient.

Step 5: Point Defense

Updated: v2026.01.30

A missile destroyer without point defense is vulnerable to counter-fire. We need at least basic self-defense capability.

PD Options for a Destroyer

  1. CIWS (Close-In Weapon System): Automated, no FC needed, short range
  2. Beam PD (Turret-mounted small lasers): Longer range, requires FC and power
  3. PD Missiles (interceptors): Longest range, uses launchers and magazines

For a 6,000-ton destroyer with limited tonnage remaining, CIWS is the most tonnage-efficient choice.

Decision: 2x CIWS-1 (Twin Gauss Cannon)

CIWS specs:
  Size: 2 HS each (100 tons each)
  Tracking speed: 5,000 km/s (base)
  Rate of fire: 2 shots per 5-second increment
  Range: 10,000 km
  No FC or power required (self-contained)

Total PD allocation: 4 HS = 200 tons

Two CIWS provide overlapping defensive coverage. Against a 4-missile salvo incoming:

PD engagement window: ~2 seconds at closing speed of 5,000 km/s
Shots per CIWS: ~2 per 5-sec window
Hit chance: min(1.0, FC_Tracking / Missile_Speed) = min(1.0, 5000/4800) = ~100%
  But with range factor: effective ~30-40% per shot (accounting for engagement window)
Expected kills: 2 CIWS * 2 shots * 0.35 = 1.4 missiles destroyed per salvo

This is modest defense – enough to thin out small salvos but not stop a concentrated barrage. The destroyer relies on its task group’s combined PD umbrella for serious missile defense.

Tip: A flotilla of 4 destroyers with 2 CIWS each provides 8 CIWS total for area defense. Task group PD is calculated collectively – ships protect each other. Design your PD around the flotilla, not individual ships.

Step 6: Engine and Speed

Updated: v2026.01.30

A missile destroyer needs speed to maintain range advantage and retreat if engaged by beam ships.

Target speed: 3,500+ km/s (faster than most cruisers, able to dictate engagement range)

Ship size: 6,000 tons = 120 HS
Engine allocation: ~35% of tonnage = 2,100 tons = 42 HS
Split: 3x 14 HS engines (redundancy, HTK = sqrt(14) = 3.74 each)

With Nuclear Thermal at 5 EP/HS, 1.25x boost:
EP per engine = 14 * 5 * 1.25 = 87.5 EP
Total EP = 3 * 87.5 = 262.5 EP

Speed = 262.5 * 1000 / 120 = 2,188 km/s

That is below our 3,500 km/s target. Let us increase engine allocation to 45%:

Engine allocation: 45% = 2,700 tons = 54 HS
Split: 3x 18 HS engines (HTK = sqrt(18) = 4.24 each)

EP per engine = 18 * 5 * 1.25 = 112.5 EP
Total EP = 3 * 112.5 = 337.5 EP

Speed = 337.5 * 1000 / 120 = 2,813 km/s

Still below target. For a destroyer, we may need to accept lighter armor and push to 50%:

Engine allocation: 50% = 3,000 tons = 60 HS
Split: 3x 20 HS engines (HTK = sqrt(20) = 4.47 each)

EP per engine = 20 * 5 * 1.25 = 125 EP
Total EP = 3 * 125 = 375 EP

Speed = 375 * 1000 / 120 = 3,125 km/s

Decision: 3x 20 HS engines, 50% tonnage allocation, 3,125 km/s

This is a missile destroyer doctrine: speed over armor. We engage at range and run from beam ships.

Step 7: Remaining Components

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Sensors

A missile destroyer needs an active sensor to detect targets for fire control lock:

Active Sensor: 3 HS (150 tons), Resolution 100
  Detects 10,000-ton ships at ~350,000 km
  Sufficient for missile FC targeting

Armor

With 50% in engines and significant launcher/magazine space, armor must be minimal:

Armor: 2 layers Duranium
  Strength per column: 2 * 5 = 10
  Mass: approximately 750 tons
  Philosophy: survive glancing hits, not sustained beam fire

Support Systems 

Bridge: 50 tons (1 HS) -- mandatory
Engineering: 300 tons (6 HS, 5%) -- maintenance and repair
Fuel: 750 tons (15 HS) -- range for system operations

Step 8: Final Design Summary

Updated: v2026.01.30

Mass Budget

Component Mass (tons) HS
Engines (3x 20 HS) 3,000 60
Missile Launchers (8x size-2) 800 16
Magazines (2x 3 HS) 300 6
Missile Fire Controls (2x 4 HS) 400 8
CIWS (2x 2 HS) 200 4
Active Sensor (1x 3 HS) 150 3
Armor (2 layers Duranium) ~750 –
Fuel Tanks 750 15
Bridge 50 1
Engineering (5%) 300 6
Total ~6,700 –

Over budget by ~700 tons. Iteration needed:

  1. Reduce fuel to 500 tons (10 HS) – saves 250 tons, shorter range but acceptable for system defense
  2. Reduce engineering to 4% (240 tons) – saves 60 tons, slightly higher failure rate
  3. Reduce magazines to 2x 2 HS (200 tons) – saves 100 tons, ~34 missiles still provides 4 full salvos
  4. Trim sensor to 2 HS (100 tons) – saves 50 tons, shorter detection but FC provides targeting
  5. Reduce armor to 1.5 layers – saves ~250 tons, but reduces survivability

Revised total after trims: ~6,040 tons – within tolerance for the ship designer to handle.

Final Performance 

DD-6000 "Lancer" Missile Destroyer
  Tonnage: ~6,000 tons (120 HS)
  Speed: 3,125 km/s
  Armament: 8x Size-2 Missile Launchers (ASM-2 "Javelin")
  Magazines: 40+ missiles (5 full salvos)
  Fire Control: 2x Missile FC (continuous salvo capability)
  Point Defense: 2x CIWS-1
  Sensor: Active, resolution 100
  Armor: 2 layers Duranium (10 strength per column)
  Range: ~3.2 billion km
  Engine redundancy: 3 engines, HTK 4.47 each

Flotilla Composition

The Lancer operates in flotillas of 4-6 ships:

4-ship flotilla:
  Total launchers: 32
  Salvo size: 32 missiles
  Salvo damage: 32 * 1.6 = 51.2 damage (devastating against cruiser armor)
  Total PD (collective): 8 CIWS
  Combined sensor coverage: overlapping detection zones

A 32-missile salvo every 30 seconds provides withering firepower. Against a 10,000-ton cruiser with 3 layers of armor (15 strength per column), concentrated hits will breach armor within 2-3 salvos and begin destroying internal components.

Upgrade Path

Updated: v2026.01.30

Near-Term Improvements

  1. Better warhead tech (Strength-6): Damage jumps from 1.6 to 2.4 per missile (+50%)
  2. Faster missile engines: Higher speed means less PD engagement time and better agility
  3. Reduced-size launchers: Technology reduces launcher size, freeing tonnage for more launchers or armor
  4. Better CIWS tracking: Higher tracking speed dramatically improves PD hit chance

Long-Term Redesign Triggers

  • When Nuclear Pulse engines (8 EP/HS) are researched: same engine mass gives 5,000 km/s
  • When size-3 launchers become practical: bigger missiles carry larger warheads
  • When box launchers are available: pre-loaded launchers with no magazine needed (one-shot, but very tonnage-efficient for alpha strikes)

Common Mistakes

Updated: v2026.01.26

  1. All warhead, no engine: A missile with 1.5 MSP warhead and 0.5 MSP engine is slow, easy to intercept, and short-ranged. Balance is critical – speed saves missiles from PD.

  2. No seeker on anti-ship missiles: Without an onboard sensor, missiles require continuous FC guidance to impact. If the firing ship loses sensor lock (ECM, destruction, range), the missiles go ballistic and miss.

  3. Single magazine: One magazine explosion destroys your entire ammunition supply AND deals catastrophic internal damage. Always split ordnance across multiple magazines.

  4. Forgetting reload time: Launchers fire their loaded missile instantly but take 30+ seconds to reload from magazines. Plan your engagement around reload cycles, not instantaneous fire.

  5. PD neglect on missile ships: “We engage at range, we do not need PD” fails the moment an enemy missile salvo reaches you. Even modest CIWS coverage saves ships.

  6. Speed neglect: A missile destroyer caught at beam range dies quickly with only 2 layers of armor. Speed is your primary defense – maintain range superiority at all times.

References

\hypertarget{ref-ex-mdd-1}{[1]}. Aurora C# v2.2.0+ missile mechanics: Point defense hit chance uses speed ratio: PD_Hit_Chance = min(1.0, FC_Tracking / Missile_Speed). Agility is no longer used in PD calculations. See Appendix A for the complete formula.

\hypertarget{ref-ex-mdd-2}{[2]}. Aurora C# game database (AuroraDB.db v2.7.1) – Magazine capacity is approximately 17-18 MSP per hull space, not 50. Verified against multiple magazine component entries in the database.

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