Subcom13 (Submarine Commander)

Warning

This game mode is currently a Work In Progress. Mechanics, balance, and vessel stats are subject to change. Report bugs and feedback on the Civ13 GitHub.

Introduction

Subcom13 is a submarine warfare simulation mode set on a fictional 1000x1000 nautical mile coordinate grid. You command a submarine (or crew one with other players) and must navigate the open ocean, engage hostile surface and air contacts, manage your ship's reactor and crew survival, and complete objectives relayed to you over encrypted radio.

The mode features:

Real-time navigation on a virtual overworld map with heading, speed, and depth control
Nuclear and diesel-electric submarine propulsion options
Weapons systems: torpedoes with acoustic homing, fire control consoles
Sensor suites: passive and active sonar, surface radar
Environmental simulation: hull breaches, flooding, water accumulation, and atmospheric pressure
NPC hostile contacts: surface combatants, aircraft, and enemy submarines with AI state machines
Mission objectives: sink cargo ships, patrol sectors, escort allies, recon, rescue, and ambush
Crew management: track individual crew health, oxygen status, injuries, and assignments
Single-player mode: toggle via admin panel to allow ghosts to operate machinery

Submarine Controls

Your submarine is controlled from the bridge consoles. Each console is an Alt+Click interaction.

Helm Control Station

The primary navigation console. Controls heading, speed, and depth.

Control	Description
Target Heading	Set in degrees (0-359). The sub turns toward this heading automatically.
Target Speed	Set in knots. Your sub accelerates/decelerates toward this value.
Target Depth	Pre-set depth buttons: Surface (0m), Periscope (15m), Deep (150m), Crash Dive (250m).
Emergency Blow Ballast	Instantly vents all ballast tanks and surfaces the sub.

Tip

Diesel-only submarines can only produce propulsion power when surfaced. Submerged, you run on battery at reduced speed (8 knots max).

Reactor Control Station

Manages the two nuclear reactors. Each reactor operates independently.

Control	Description
Control Rods	0-100%. Lower = more heat, more power. 100% = fully inserted (shutdown).
Primary Pump	Coolant flow rate (0-18 RPM). Higher = better heat dissipation.
Secondary Pump	Turbine steam flow (0-10 RPM). Determines power output in MW.
SCRAM	Emergency shutdown. Inserts rods to 100% instantly.

Reactor Meltdown: If core temperature exceeds 1000 C, the reactor melts down. This causes radiation damage in the reactor room and permanently disables that reactor. There is no recovery from a meltdown.

Danger

Never pull control rods below 25% without sufficient primary pump speed. Heat will spiral out of control and cause a meltdown within seconds.

Power Output Formula: MW = secondary_pump_speed * (core_temp * 0.01). You need at least 5 MW total (combined) to run the nuclear turbines for full-speed propulsion (30 knots).

Auxiliary Systems Console

Controls environmental systems and battery power.

Control	Description
O2 Generator	Toggles electrolysis. Consumes 50 kW/tick. Generates oxygen across all compartments.
Battery	Current charge / max capacity in kWh. Drains when running on electric power.
Ventilation	Per-compartment vent controls. Open/close vents to equalize air between rooms.
Fire Suppression	Activates fire suppression in a compartment.

Radar Console

Surface detection system. Only works when surfaced.

Control	Description
Power	Toggle radar on/off (surface only).
Range	Toggle between Short (20km) and Long (50km). Long range uses more power (50 kW vs 10 kW).
Detected Contacts	Shows surface contacts: name, range, bearing.

Sonar Console

Underwater detection system. Works at any depth.

Control	Description
Power	Toggle sonar on/off.
Mode	Toggle between Passive (stealth, 5 kW, only detects submerged contacts) and Active (loud ping, 100 kW, detects all contacts but reveals your position).
LOFAR Analysis	Frequency analysis display. Shows propeller cavitation and engine harmonics.
Detected Contacts	Shows submerged contacts: name, range, bearing, noise signature.

Warning

Active sonar emits a loud ping (noise level 100) that hostile NPCs can detect from long range. Use passive sonar when trying to remain undetected.

Weapons Control Station

Torpedo fire control system.

Control	Description
Master Arm	Must be ON to fire torpedoes.
Tube Status	Shows which of the 4 tubes are loaded/empty.
Target Selection	Select a detected contact as your target. Torpedoes home toward the selected target.
Launch	Fires a torpedo from a loaded tube toward the selected target.

Torpedo Stats: 40 knots, 800 unit range, 150 base hull damage. Homing torpedoes track the target automatically.

Radio Console

Encrypted command communications. Receives mission objectives and displays mission status.

Control	Description
Transmission Log	Shows all received messages with timestamps.
Mission Status	Shows current objective type, target coordinates, and target integrity.
Fast Travel	Engages 10x speed multiplier. Auto-disables when a hostile contact is within 50nm or if speed drops below 5 knots.

Flooding & Water Physics

When your submarine takes damage (torpedo hits, depth charges, crush depth), hull breaches can occur, flooding compartments with seawater.

How Flooding Works

Hull Breach: A damaged hull wall (sub_hull) loses integrity. When it hits 0, the wall is breached and water begins pouring in at 5 cm/tick.
Water Accumulation: Deck tiles (sub_deck) accumulate water measured in centimeters (0 = dry, 200 = fully flooded).
Water Spreading: Water flows to adjacent tiles within the same compartment, equalizing depth.
Bulkhead Containment: Internal bulkheads are watertight by default. If a bulkhead is destroyed, water flows through it to adjacent compartments.

Water Depth Effects

Depth	Effect
0-29 cm	Thin film. No gameplay effect.
30-49 cm	Ankle-deep. Visual change.
50-99 cm	Drowning risk begins. Mobs take minor respiratory stress.
100-149 cm	Waist deep. Movement is difficult. Continuous losebreath buildup.
150-199 cm	Chest deep. Heavy brute damage (8/tick), severe drowning, CO2 buildup.
200 cm	Fully flooded. Tile is underwater.

Bilge Pumps

Located in various compartments. Activate by clicking them.

Standard Bilge Pump: Drains 10 cm/tick from its tile + adjacent tiles. Uses 15 kW/tick. Range: 1 tile.
Emergency Bilge Pump: Drains 5 cm/tick, single tile only. Uses 8 kW/tick.

Note

Bilge pumps require battery power. If your battery is dead, the pumps will not function. Prioritize keeping the diesel generators running if your reactors are offline.

Hull Breach Sealant Sprayer

An automated device that scans for breached hull walls and seals them with fast-curing polymer. Each use consumes one unit of sealant (100 units total). Requires 10 kW/tick to operate.

Atmospheric System

Each compartment has independent atmospheric simulation:

Oxygen (O2): Consumed by mobs breathing. Depleted O2 causes suffocation. Replenished by the O2 generator (electrolysis).
Carbon Dioxide (CO2): Produced by mobs. Levels above 5.0 cause respiratory distress and CO2 poisoning.
Pressure: Calculated from gas moles and temperature. Normal = 1 atm (101.325 kPa).

Ventilation Ducts

Link compartments together for air sharing. All ducts with the same vent ID form a network. Air gradually equalizes across the network.

Object	Function
Ventilation Duct	Passive air equalization. Click to open/close.
CO2 Scrubber	Active CO2 removal (0.5 moles/tick). Optionally injects O2. Uses 25 kW/tick.

Tip

If a compartment is flooding, the water displaces oxygen. A fully flooded compartment will have almost no breathable air. Prioritize evacuation or O2 injection.

Vessel Roster

Player Submarine

Stat	Nuclear Sub	Diesel Sub
Max Speed (surfaced)	30 knots	18 knots
Max Speed (submerged)	30 knots	8 knots (battery)
Propulsion	Nuclear reactors	Diesel generators (surfaced only)
Battery	3000 kWh	3000 kWh
Diesel Fuel	40000 L (backup)	40000 L (primary)
Crush Depth	300m	300m
Torpedo Tubes	4	4

Hostile Surface Combatants

Vessel	Type	Speed	Hull	Sensors	Weapons
Oliver Hazard Perry FFG	Frigate	30 kts	800	Sensor 40km, Sonar 25km	Harpoon Missiles, Mk 46 Torpedoes
Kirov CGN	Battlecruiser	28 kts	1200	Sensor 50km, Sonar 30km	P-700 Granit, SS-N-14 Silex, 53-65 Torpedoes
Krivak FFG	Frigate	26 kts	600	Sensor 35km, Sonar 20km	RBU-6000 Depth Charges, SET-65 Torpedoes
Nanuchka Corvette	Corvette	32 kts	450	Sensor 25km, Sonar 15km	P-120 Malakhit, 40mm CIWS
Grisha MPK	Patrol Boat	24 kts	350	Sensor 20km, Sonar 18km	RBU-2500 Depth Charges, SA-N-4 Gecko

Hostile Submarines

Vessel	Type	Speed	Hull	Sensors	Weapons
Kilo-class SSK	Diesel Sub	18 kts	700	Sensor 30km, Sonar 35km	TEST-71 Torpedoes, Type 65-76 Torpedoes
Akula-class SSN	Nuclear Sub	30 kts	900	Sensor 40km, Sonar 45km	SS-N-16 Stallion, 53-65K Torpedoes
Delta III SSBN	Ballistic Sub	22 kts	1100	Sensor 25km, Sonar 30km	R-29 Vysota SLBM, 53-65M Torpedoes

Hostile Aircraft

Aircraft	Type	Speed	Hull	Sensors	Weapons
Tu-22M Backfire	Bomber	50 kts	400	Sensor 80km	AS-4 Kitchen, AS-6 Kingfish
Su-24 Fencer	Strike	45 kts	300	Sensor 60km	AS-7 Kerry, FAB-500 Bombs
Il-38 May	ASW Patrol	38 kts	350	Sensor 70km, Sonar 10km	RGB-1N Torpedoes, RGB-2 Depth Charges

Neutral / Mission Targets

Vessel	Type	Speed	Hull	Sensors	Notes
Bulk Cargo Freighter	Cargo	15 kts	500	Sensor 15km	Large radar signature (2.0x). Common mission target.
Fleet Oil Tanker	Tanker	12 kts	400	Sensor 12km	Very large signature (2.5x). Catastrophic explosion on death.

AI Behavior

Hostile NPCs use a three-state AI with tactical movement:

State	Behavior
PATROL	Moves between random waypoints at patrol speed. Non-hostile until detection.
HUNT	Triggered when the NPC detects the player (passive noise or active sonar ping). Moves toward the player's last known position at attack speed.
ATTACK	When within weapon range, the NPC circle-strafes around the player while firing weapons on cooldown. Maintains a tight orbit (25 unit radius) to avoid torpedo lock. Reverts to HUNT if the player moves out of range.

Detection Triggers:

Passive Sonar: NPC detects you if your noise_level exceeds their passive_sonar_threshold. Noise increases with speed and active sonar use.
Active Sonar Ping: If you use active sonar within the NPC's sonar range, they instantly know your position.

Tactical Behavior:

NPCs circle in a random direction (clockwise or counter-clockwise) at 8 degrees per tick
They fire one weapon per volley cycle with cooldown management
If you move beyond 40 units, they switch to HUNT to chase you

Tip

Stay deep and slow to minimize your noise signature. A submarine running at 5 knots at 200m depth is extremely difficult to detect passively.

Crew Management

The submarine tracks individual crew members and their status. Crew are automatically detected when they board the submarine.

Crew Member Status

Each crew member is tracked with:

Stat	Description
Health	Current health percentage (0-100)
Total Damage	Sum of brute, burn, toxin, and oxygen damage
Conscious	FALSE if unconscious or dead
Injured	TRUE if total damage exceeds 20
Oxygen Status	"Nominal", "Low O2", "Suffocating", or "Drowning"
Compartment	Current compartment ID (e.g., "Operations", "Reactor Room")
Assignment	Job title (Captain, Officer, Crewman)
Role	"captain", "officer", or "crew"

Crew Query Procs

The submarine datum provides these crew management functions:

Proc	Returns
`get_crew_count()`	Total number of tracked crew members
`get_crew_by_role(role)`	List of crew members matching a role
`get_injured_crew()`	List of crew members with damage > 20
`get_suffocating_crew()`	List of crew members with non-nominal oxygen
`get_crew_in_compartment(id)`	List of crew in a specific compartment
`get_crew_summary()`	Associative list: total, injured, suffocating, unconscious counts

Crew Auto-Detection

Crew are automatically added to the tracking list when:

They are a /mob/living/human on the submarine's Z-level
They are standing on a turf in internal_turfs (the submarine interior)
They are not already tracked

Dead crew members are automatically removed from tracking.

Mission System

Missions are relayed to you over the radio console. Complete objectives to earn mission points and progress through the game.

Mission Types

Type	Objective	Completion	Failure
SINK_CARGO	Destroy a hostile cargo vessel at target coordinates	Sink the target vessel	Target escapes or 120 tick timeout
PATROL_AREA	Navigate to and patrol a sector	Reach coordinates and survive 60 ticks	Take too much damage or 60 tick timeout
ESCORT	Protect a friendly cargo vessel to waypoint	Cargo survives to destination	Cargo is destroyed
RECON	Investigate coordinates and observe	Reach target and maintain position 30 ticks	Take damage or leave area
RESCUE	Find and escort a damaged allied submarine	Escort sub to safe waters	Allied sub is destroyed
AMBUSH	Set up and eliminate a hostile patrol group	Destroy all hostiles	Fail to eliminate all or 120 tick timeout

Mission Weighting

Missions are randomly selected with these weights:

Type	Weight
SINK_CARGO	30%
PATROL_AREA	25%
ESCORT	20%
RECON	15%
AMBUSH	8%
RESCUE	2%

Mission Timing

Delay Between Missions: 150 ticks (approximately 2.5 minutes)
Mission Timeout: 120 ticks (approximately 2 minutes) for most types
Completion Check: Every tick while mission is active

Mission Scoring

Completed: +1 to missions_completed counter
Failed: +1 to missions_failed counter
Mission Status: Displayed in radio console and map metadata

Single Player Mode

Single-player mode allows ghosts to interact with submarine machinery, enabling solo play without other human crew.

How to Enable

Open the Server tab in the game menu
Select "Toggle Single Player Mode"
Requires admin privileges

Effects

When enabled:

Ghosts can interact with all submarine consoles and physical machinery
Dead players can operate systems while observing
All machinery can_use() checks are bypassed for observers

When disabled:

Only living players can interact with machinery
Ghosts cannot operate systems

Note

Single-player mode is intended for testing and solo gameplay. It can be toggled at any time by an administrator.

Physical Machinery (Interior)

These objects exist on the submarine's interior Z-level and can be interacted with directly.

Object	Location	Interaction
Reactor Core	Reactor Room	Visual indicator of reactor status. Emits radiation if damaged.
Coolant Pump	Reactor Room	Degrades with health. Damaged pumps reduce max RPM.
Steam Turbine	Engine Room	Caps max speed based on health. Makes noise at high speeds.
Diesel Engine	Engine Room	Carbon buildup at low throttle. Overheats at high throttle.
Diesel Propulsion Motor	Engine Room (diesel only)	Converts diesel power to thrust. Overheats and seizes if damaged.
Torpedo Tube	Forward/Aft Torpedo Room	Load/unload torpedoes. Click with a torpedo item to load, crowbar to unload.
HTP Fuel Tank	Torpedo Room	High-test peroxide storage. Volatile if damaged or heated. Explodes at 70 C.
Bunk Bed	Crew Quarters	Rest area. No gameplay effect yet.
Galley	Galley	Food processor. Produces nutritional rations when clicked.
Equipment Locker	Various	Contains gas masks, welding tools, fire extinguishers, and basic tools.
Stern Plane	External	Affects steering efficiency. Must be repaired while surfaced.
Bilge Pump	Various Compartments	Drains water from tiles. Standard (10 cm/tick, 15 kW) or Emergency (5 cm/tick, 8 kW).
Hull Breach Sealant Sprayer	Various Compartments	Seals breached hull walls. Uses sealant charges (100 total). Requires 10 kW.
Ventilation Duct	Various Compartments	Equalizes air between compartments. Click to open/close.
CO2 Scrubber	Various Compartments	Removes CO2 (0.5 moles/tick), optionally injects O2. Uses 25 kW.
Ballast Control Valve	Operations	Controls ballast tank flooding/venting for depth control.

Quick Reference

Situation	Action
Taking on water	Activate bilge pumps. Seal breaches with welder or sealant sprayer.
Running out of air	Turn on O2 generator. Open ventilation ducts.
Reactor overheating	Increase primary pump speed. Insert control rods. SCRAM if critical.
Enemy detected on sonar	Go deep (150m+), reduce speed to 5 knots, go silent.
Need to fire torpedoes	Master Arm ON. Select target from sonar contacts. Load tube. Launch.
Battery dead	Surface and engage diesel throttle to recharge.
Crush depth warning	Increase target depth. Check ballast. Emergency blow if needed.
Crew member injured	Check crew status via submarine console. Move to medical bay.
Crew suffocating	Check oxygen status. Inject O2 into compartment or evacuate.
Solo play needed	Toggle Single Player Mode in Server tab (admin only).
NPC attacking	Go deep and slow. Use passive sonar. Avoid active sonar pings.
Mission received	Check radio console for coordinates. Navigate to target area.
Multiple hull breaches	Emergency blow to surface. Activate all bilge pumps. Seal breaches.