Navigation, Sensors, and Comms

A ship that cannot see, cannot be heard, and cannot find its way is a drifting object. The systems that give a ship awareness of its environment and the ability to communicate within it are not secondary features: they are what separates an operable vessel from an expensive wreck.

This chapter covers how ships know where they are, how they find where they are going, how they detect what is around them, how they communicate across a universe built on relay infrastructure, and how AI integration ties all of it together. It also covers what happens when these systems are deliberately used against other ships.

Astrogation

Astrogation is the skill of route planning: finding seam arcs, calculating Slipstream entry and exit, plotting offset exits, navigating through poorly charted corridors, and recovering from navigation failures. It draws on the INT attribute and governs every significant navigation decision the crew makes.

When Astrogation Trials Are Required

Most navigation on established routes requires no Trial. A ship traveling a well-maintained corridor with a functioning AI navigation suite and current charts does not call for a roll to arrive at the expected destination. The AI handles it.

Trials become necessary when the situation falls outside normal parameters.

AI navigation assistance reduces the difficulty by removing 1 Trial Die (or downgrading 1 Crisis Die to a Trial Die if none remain). A functioning Navigation Directive Package and appropriate AI Core are required to receive this benefit.

Success Tiers

Astrogation Trials generate both successes and Boons. Additional successes and Boons can be spent for meaningful benefits.

The 3 Boon and Breakthrough spends are the incidental version of the Corridor Trace and Locate Candidate Seam Trials under Exploration Trials below. A navigator who turns up a secondary seam or an uncharted trait during ordinary transit has done a step of exploration without setting out to; the GM records it as the crew would record a trace.

Failure Consequences

Astrogation failures should create complications, not dead ends. The ship still arrives somewhere; the question is where and in what condition.

Failure on seam location: The ship cannot locate the arc during this approach. Transit is delayed until another attempt. If time-pressured, the crew may attempt a forced entry (see Chapter 6) with all its consequences.

Failure on offset exit: Roll on the offset-exit failure table in Chapter Six, which also carries the Trial modifiers and the Extreme leg Intervals for each offset type; this chapter does not repeat them.

Failure on corridor navigation (turbulent or Fracture route): The ship drifts off the optimal transit path. Apply 1 System Damage to the Slipstream drive and extend transit time by 1d3 days. A Calamity result may deposit the ship in an unexpected corridor branch or cause additional System Damage.

Exploration Trials

Finding a new Slipstream route is an expedition with six steps: trace the corridor, locate the candidate seam, make the first transit, survey the system on arrival, survey a body, and file or sell the record. The full procedure, its complications, and the empty-system generator are in the GM Guide. The two navigation steps are Astrogation extended checks and are summarized here.

Corridor Trace starts from one of four positions. From a known corridor that continues past its terminal seam: Average. From a Rumored atlas entry or purchased survey fragment: Hard. From a Faded Branch, Collapsed Port, or Lost seam: Hard. From open space with no prior data: Severe, and the Seam Survey Package is required. The ship holds position in the Extreme Travel Band while tracing and burns 1 Supply Unit per day. Meeting the threshold confirms the corridor and its class and reveals one Route Trait. Reaching the attempt limit means no corridor is within reach of this position.

Locate Candidate Seam is the New Seam location Trial above, run as an extended check because the seam has never been crossed and no phase wake marks it. Meeting the threshold locates a Candidate Seam at New stability, and the crew may enter. Reaching the attempt limit means no usable seam exists here for this crew; the only remaining way through is Forced Entry (Chapter Six), with all its consequences.

The first transit through a Candidate Seam uses the New seam entry, corridor navigation, and offset-exit failure rules already in this chapter and Chapter Six, at Severe for entry and exit and Hard for the transit. Survey hardware that modifies these Trials (Seam Survey Package, Astrogation Lab, Slipstream Stabilization Package) is in Chapter Ten. The Navigation Directive Package benefit applies to all three.

Sensor Systems

Sensors are how a ship perceives its environment: detecting other ships, scanning cargo, reading life signs, locating seam arcs, identifying threats, and gathering intelligence about whatever is in the local space.

Four sensor grades cover the civilian-to-military range. Every ship carries at minimum the Basic suite; the others require installation and, for Military sensors, licensing.

Detection Range

A sensor grade's most important property is the furthest Range Band at which it detects another ship at all. Everything else is detail.

Ship combat uses the Range Bands in Chapter Fifteen: Engaged, Short, Medium, Long, Extra Long, Extreme. A ship cannot detect a contact beyond its grade's listed band, and Extreme is the detection threshold itself, so a Military suite sees as far as anything in known space can.

This asymmetry is the point. A warship with Military sensors detects a freighter at Extreme and can approach through two full bands before the freighter's Standard suite registers anything. The freighter's first warning is a ship at Medium range that already has a firing solution. Crews who operate near military traffic learn to watch for the ping rather than the ship.

Basic Sensors

All ships. No license required.

Basic sensors provide the detection, IFF transponder reading, and atmospheric scanning that every crewed ship needs to operate safely. They are not combat intelligence tools. They are navigation and safety tools that happen to detect other ships. Standard on small craft, shuttles, and fighters.

Basic sensor Trials: Using Basic sensors in complicated situations (identifying a target running with transponder off, distinguishing a large rock from a small ship at range, scanning through interference) calls for an Electronics Trial at Average difficulty. Ordinary detection does not require a Trial.

Standard Sensors

Fitted to most working starships. No license required.

Standard sensors are what a Slipstream-capable hull carries out of the yard. They detect contacts at ordinary combat range, resolve enough detail to tell a freighter from a cutter, and support routine traffic control, docking, and survey work. Almost every commercial hull in the catalog uses this grade.

Standard sensor Trials: Identifying a specific ship model rather than a class, reading a contact through debris or radiation, and tracking more than one contact at once require Electronics Trials at Average difficulty.

Extended Sensors

Commercial premium. Available without license.

Extended sensors add reach, passive listening, cargo manifest reads, and analytical detail. They are used by prospectors, couriers with intelligence contracts, corporate vessels doing route surveillance, and any commercial operator who needs to know more about their environment than a standard suite provides.

Extended sensor Trials: Hard identification at range, distinguishing cargo types by EM signature, passive scanning through jamming, and detailed analysis of another ship's systems require Electronics Trials at Average to Hard difficulty depending on conditions.

Military Sensors

Licensed. Restricted in most civilian ports.

Military sensors provide detection to the threshold, firing-solution data, ECM integration, and stealth detection. They are the tools that make warships genuinely more aware of their environment than commercial ships, and they are deliberately restricted because that awareness is a tactical weapon.

Military sensors cannot be operated passively when they are active. An active scan at Long range produces a detectable ping that other ships with functioning sensors will notice. The ship scanning is visible to what it scans.

Military sensor Trials: Detecting a ship in Cold Running Mode, identifying a specific ship type at Extreme range, locating a specific person aboard a scanned vessel, and maintaining tracking locks on multiple targets simultaneously require Electronics Trials at Hard to Severe difficulty.

Sensor Trials Summary

Active Scanning: What It Reveals About You

Active sensor pings are detectable. Any ship with functioning sensors in range can identify that a scan occurred and, on a Hard Electronics Trial, identify the scanning ship's approximate position.

This creates a meaningful tension at the table. Military sensors provide superior information, but using them at range announces your presence. A ship that goes active in a sensitive location is making a decision that other ships in the area can respond to.

Passive listening provides less information but produces no detectable signature. Passive Extended and Military sensors can detect broadcasting ships and read EM signatures without revealing the scanning ship's position.

Transponders and IFF

Every ship licensed to operate in known space carries a transponder. The transponder is an automatic broadcast device that transmits the ship's registry, owner identity, declared class, builder, and cargo declaration on a continuous loop. It is the legal foundation of space traffic management and the first thing any authority checks when they encounter a ship.

What a Transponder Broadcasts

Authorities use transponder data to identify ships entering their space, flag ships with outstanding warrants, check cargo declarations against known route data, verify weapons licenses, and trigger inspection protocols when declared data seems inconsistent.

A ship whose cargo declaration does not match its typical class, whose route history is unusual, or whose ownership record has gaps is flagged for closer attention automatically.

Transponder Spoofing

Operating with false transponder data is illegal in every power's jurisdiction. It is also common among smugglers, privateers, intelligence operatives, and ships whose legal status is complicated.

Spoofing a transponder requires:

1. The replacement data (a false identity, ideally a real ship that exists and is unlikely to appear in the same port)
2. Access to the ship's transponder system
3. An Electronics Trial to install the false data (Average for basic registry changes; Hard for creating convincing false ownership and cargo history)

Detection risk:

A poorly constructed spoof uses registration numbers that do not match port records, cargo declarations inconsistent with the ship's actual configuration, or owner data that cross-references to a registry flagged as fraud. A professional spoof requires access to real registry records and builds false identity from genuine but unused registration numbers.

Dark Running

A ship may disable its transponder entirely. This is Dark Running: the ship is not broadcasting any identification.

Dark running is illegal in any port space, commercial corridor, or military zone. Outside those areas, it is simply unusual.

Consequences of Dark Running:

• Any ship with functioning sensors can identify the absent transponder signal
• Authorities in transponder-monitored zones will log the absence and may dispatch an inquiry vessel
• Traffic control systems will not assign corridor priority or safe approach vectors
• Emergency distress protocols cannot automatically identify the ship
• Military ships treat transponder-dark contacts as suspicious by default; some military zones treat them as presumptively hostile

Dark running provides privacy at the cost of legitimacy. A ship running dark in open space is simply invisible to routine monitoring. A ship running dark in a commercial port approach is making a statement that requires an immediate explanation.

Phased Relay Communications

Interstellar communication in Void Drifters uses phased relay stations: installations built near established Slipstream seams that transmit compressed data packets through the same corridor geometry used by ships. A relay network allows news, financial records, orders, credentials, and messages to move faster than physical vessels.

How Relay Communication Works

A message sent through a relay is compressed, encrypted to its recipient's credentials, and transmitted through the corridor's phase geometry. The relay at the far end receives the packet and retransmits it toward its destination. A message traveling through a chain of relays may take hours to days to reach its destination, depending on the number of links and the relay station's current traffic load.

Relay uplink is a ship system. A ship connects to the nearest active relay, authenticates with its registry credentials, and can send and receive messages through the network. Most ships with functioning communications can do this automatically when within relay range of an active station.

Communication lag: Relay messages are not instantaneous. A message sent from a Shoiyan Concord station to an Irnan Directorate station on the other side of known space may take several days to traverse the relay chain, even at relay speeds. This lag is meaningful for intelligence, diplomacy, and time-sensitive instructions.

Relay Failure and Fringe Space

Relay infrastructure exists on established routes near active seam arcs. In fringe space, isolated systems, newly settled colonies, and systems where the seam is fading, relay coverage is intermittent or absent.

When relay coverage is absent or degraded:

A colony that loses relay access does not immediately lose all communication. It loses fast communication. The slowdown of information is often more dangerous than the total loss: a colony that gets news weeks late is operating on outdated intelligence about conditions, prices, and threats.

Relay Censorship and Monitoring

Every major power monitors relay traffic through its sovereign territory. This monitoring varies from passive metadata collection (who is talking to whom) to active content inspection of unencrypted traffic. Military relay stations inspect traffic more aggressively than commercial ones.

Encrypted messages are harder to read but not invisible: the metadata (origin, destination, size, timing) remains visible even when content is protected. Authorities can infer significant information from metadata alone.

The Caliphate operates the most aggressive relay monitoring system in known space. Jaziri relay stations check credentials, log all traffic, scan for unauthorized encryption formats, and flag communications consistent with political or religious dissent. Relay censorship in Caliphate space is not theoretical; it is routine.

In League space, monitoring is lighter but commercial. Corporations have licensing agreements with relay operators that allow traffic analysis for commercial intelligence purposes.

In fringe space, relay stations are often operated by independent parties with no particular loyalty to any power. Their monitoring practices vary from careful neutrality to active information brokerage.

The Ship AI Core and Directive Intelligence

The AI Core is a ship system. It is not crew, but it is not furniture. It provides the navigation assistance, sensor management, fire control coordination, damage monitoring, and automated response capability that separates a modern ship from an early-era vessel crewed entirely by specialists.

What it does not do is make decisions. It executes directives. The crew decides; the AI implements.

AI Core Ratings

Every AI Core is rated by the number of active support channels it can maintain during structured play and the number of Directive Packages it can hold.

An Active Channel is the AI's capacity for real-time assistance during a structured encounter. Each active channel may support one AI-assisted Trial per round. If all channels are in use, the crew must wait or redirect one.

Redirecting an unused channel to a new task is a Quick Action. Redirecting a channel already used this round requires a Maneuver.

Directive Packages

An AI can assist only within its installed Directive Packages. A ship may have an Advanced AI Core and still lack the package for a specific task.

When all five conditions are met (a functioning AI Core, the appropriate Directive Package, a functioning relevant system, a clear directive from the crew, and the action within the package's scope) the AI removes 1 Trial Die from the difficulty pool (or downgrades 1 Crisis Die to a Trial Die if no Trial Dice remain).

AI Core in Navigation and Sensors

The Navigation Directive Package makes a significant difference to Slipstream operations. Add 1 Boon Die to Trials for seam location, offset exit calculation, and corridor navigation when this package is active. Viridian ships with their enhanced AI integration also remove 1 Bane Die from these same Trials when running native Viridian architecture.

The Sensors package extends what the crew can extract from their sensor suite: Add 1 Boon Die to scan and target identification Trials when the package is active and the relevant sensor suite is functioning.

The One-Channel Limit

No Trial can benefit from more than one AI Directive Package. If both Navigation and Sensors packages could plausibly assist a scan-and-identify Trial, choose the most applicable. Multiple packages do not stack their benefits.

AI Core Damage

When the AI Core suffers System Damage, the channel count and package access degrade.

A damaged AI Core can be patched with an Engineering or Craft Trial to restore temporary function, subject to normal repair rules.

Jaziri Echo and AI Corruption

In rare circumstances, typically when dealing with salvaged Jaziri military systems, advanced AI research, or AI Cores that have been deliberately modified beyond their rated parameters, a Calamity on an AI-assisted Trial may trigger a Jaziri Echo.

A Jaziri Echo is a subtle sign that something beyond the local system has touched the scene. The AI may refuse an order it should be incapable of evaluating. A damaged navigation suite may identify a safe exit no available chart contains. A salvaged component may authenticate credentials no crew member possesses.

A Jaziri Echo should create a question, not a solution. It is a GM tool, not a routine mechanical event. It should be used only when the encounter is plausibly connected to AI research, Jaziri military systems, relay networks, or circumstances where the hidden AGI would have meaningful interests.

Electronic Countermeasures and Sensor Warfare

Electronic warfare is the competition between information and denial of information. A ship that cannot be scanned has a significant tactical advantage. A ship that can jam an enemy's weapons lock can survive a fight it would otherwise lose.

ECM as a Ship System

An Electronic Countermeasures suite requires Module Slot space and Power Load while active. It provides access to several tactical options but cannot be used simultaneously for all of them: the crew must choose which ECM function is active each round.

ECM requires: An installed ECM module, an active Electronic Warfare Directive Package in the AI Core, and crew action to direct specific functions.

Jamming

Jamming broadcasts electromagnetic interference that degrades enemy sensors and targeting systems within range.

Initiating a jam: Electronics Trial (Average for civilian ECM, none required for Military ECM against civilian sensors). On success, targets within Medium range add 2 Bane Dice to all Electronics-dependent Trials (sensors, targeting, communications relay). Duration: until the crew stops the jam or the ECM takes damage.

Jam detection: Any ship with functioning sensors that attempts an Electronics Trial (Average) can identify the jam source and approximate location. Jamming is not anonymous.

Counter-jamming: A ship with its own ECM suite may attempt to counter an active jam with an opposed Electronics Trial. On success, the jam's Bane Dice do not apply to that ship's Trials.

Military ECM advantage: Safa ships may activate ECM as a defense reaction once per round without consuming a crew action. Military ECM extends jamming range to Medium and adds 1 additional Bane Die to targets.

Sensor Ghost

A sensor ghost is a false return: an ECM-generated signal that appears as a ship on enemy sensors.

Creating a ghost: Electronics Trial (Hard). On success, the ghost reads as a ship of specified rough Scale on enemy sensors. It does not move intelligently, does not respond to hails, and does not have a transponder. Maintaining the ghost requires 1 Power Load and concentration from the electronic warfare operator.

Detecting a ghost: Electronics Trial (Average for Military sensors; Hard for Extended; not possible for Basic). A ghost that is hailed and does not respond raises suspicion immediately.

Electronic Silence

Electronic silence is the full EM shutdown: transponder off, active sensors offline, all broadcasting systems silent. The ship exists only on passive thermal and visual detection.

Electronic silence is distinct from Cold Running Mode (which is about thermal signature). A ship can run electronically silent without running cold, or run cold without running electronically silent, or attempt both simultaneously.

Electronic silence provides:

• No transponder broadcast
• No active sensor pings
• No relay communications
• No targeting lock emissions

Electronic silence costs:

• Cannot use active sensors (passive Extended sensors still function)
• Cannot send or receive relay communications
• Cannot use targeting-dependent weapons (must use manual targeting at reduced effectiveness)
• Pilot Trials for precise navigation add 1 Bane Die (no AI navigation coordination)

Detection while electronically silent: Extended passive sensors can detect the ship's thermal and electromagnetic signature at Short range on a Hard Electronics Trial. Military sensors may detect at Medium range on a Hard Trial.

Sensor Warfare at the Table

The practical pattern at the table is this: the ship that sees first and is seen least has a significant advantage. That advantage must be paid for in system slots, Power Load, crew attention, and the willingness to operate in conditions that legitimate ships do not.

A smuggler runs electronically silent through a patrol zone and navigates by passive sensors, accepting the Bane Die on precision navigation and hoping the patrol's Basic sensors do not do a thermal sweep. A military corvette uses active Military sensors to light up everything within Long range, accepting that everything in that range now knows the corvette is there. A pursuit ship uses ECM jamming to degrade the quarry's ability to call for help while closing distance.

Each choice involves a real cost. Electronic warfare is not a free advantage; it is a set of trade-offs that good operators manage better than careless ones.