Supplement Four
SOC-14 5K
SENSOR rules for use with Classic Traveller
-BASELINE-
From pg. 76 of The Traveller Book, under "Detection" ...Ordinary or commercial starships can detect other ships out to a range of about one-half light-second (about 150,000 km). Military and scout starships have detection ranges out to two light-seconds (600,000 km).
Ships which are maintaining complete silence cannot be detected at distances of greater than half dectection range; ships in orbit around a world and also maintaining complete silence cannot be detected at distances greater than 1/8 detection range. Planetary masses and stars will completely conceal a ship from detection.
From pg. 76 of The Traveller Book, under "Tracking" ...Once a vessel has been detected, it can be tracked by anyone up to three light-seconds (about 900,000 km).
From pg. 57 of The Traveller Book, under "The Bridge" ...Basic controls, communications equipment, avionics, scanners, detectors, sensors, and other equipment for proper operation of the ship are included in the cost and tonnage allocation of the vessel's bridge.
-SENSORS-
Space is vast, almost entirely empty and very, very cold such that even gases freeze solid. A ship's drives have to emit a lot of energy to provide any reasonable thrust, so the energy from a manuvering ship is very easy to detect against the super-cold background of space.
Even if a ship turns off its drives, it has to maintain a reasonable internal temperature for its crew; it contains a power plant which has to power a lot of electrical equipment (life support, computers, etc.). These systems all emit heat (as a waste by-product) which must be shed from the ship to prevent it building up and cooking the crew. Even a carefully contructed 'stealthy' ship must find a way to get rid of this energy, and can therefore be detected using the advanced sensors available in Known Space.
It is generally pretty easy to detect the presence of other starships and extact a fair amount of information as to the ship's type and status, based on its energy emissions.
The filtering of background noise is the limiting factor with modern sensor systems, and a ship's ability to filter electromagnetic energy emitted from a gas giant or background radiation from a system's star is directly related to the quality and capability of the ship's computer and sensor operator.
-SENSOR GRADE-
Sensors come as either standard grade or military grade equipment. Both grades include various active and passive sensors, but specific sensor type and operational parameters are not distinguished in these rules other than to say that military grade sensors are about four times as senstive as standard grade packages.
Military grade sensors are typically restricted and unavailable to those vessels built outside of a military organization, but exceptions do exist (at the choice of the GM). Scout craft typically employ military grade equipment.
-TRANSPONDERS-
By Imperial Law, transponders continually broadcast a vessel's ID and relevant information. When a ship emerges from J-Space, it is bombarded by multiple contacts in a busy system--the transponder signals broadcasting ID and current position of each vessel.
Military vessels have transponders that can be adjusted to broadcast altered ID information. They also have the ability to cease transponder transmission all together. But, all civilian ships must incorporate a transponder that constantly broadcasts and cannot be silenced.
Of course, the military grade transponders find their way to the grey and black market, and they can be had for a price. The penalty for being caught with such a device is high and can include imprisonment or forfeiture of the ship (or both). Transponder inspections are common as part of IAP (incoming-arrival procedure) with many worlds in the Imperium. One would think that corsairs with such a transponder would have an edge over the civilian traffic the pirates prey upon, and in some respects, this does pose a problem to civilian traffic. But, a ship approaching without a transponder broadcast can be blasted from the sky without warning--it being perfectly legal to do so. Corsairs have learned to be more crafty, either by broadcasting a false signal or finding position on a vessel by hiding behind a moon/planet/asteroid/satellite in space, and wounded corsairs find the number of ports where they can make port sparse as officials have to be paid to look the other way.
RULE: A -4DM is applied to the detection roll of any vessel broadcasting transponder ID.
-SENSOR OPS-
Sensor Operation is the skill associated with operating the ship's sensors and interpreting it's readings. Several Traveller skills provide expertise in Sensor Ops. GMs may wish to replace skills on character generation tables with the Sensor Ops skill.
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">Skill Sensor Ops
------------ -------------------------
Navigation at same skill level
Pilot at skill minus one level
Ship's Boat at skill minus one level
Gunner at skill minus two levels
Recon at skill minus one level
Survey at same skill level</pre>[/QUOTE].
-SENSOR RANGE-
Sensor range is variable and reliant on a number of factors. Under these rules, sensor grade determines its range. The table provides sensor range in light-seconds and kilometers.
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">Sensor Package Close/Short/Long Close/Short/Long
--------------- ------------------ ------------------
Standard Grade 0.33/0.50/1.00 LS 100K/150K/300K km
Military Grade 1.00/2.00/3.00 LS 300K/600K/900K km</pre>[/QUOTE]Each listed range is a distance from the ship measured in all directions. For example, a standard grade sensor performs a close range scan on everything within 100,000 km of the ship. At short range, the scan is a sphere, centering on the ship, scanning 150,000 km in all directions. Long range scans stretch out to one light-second (300,000 km) in all directions.
-DETECTION THROW-
Ship's sensors are operated by focusing them on one of the three ranges indicated in the chart above: Close Range Scan; Short Range Scan; Long Range Scan. A separate throw is needed for each scan. In actuality, the ship's sensors are constantly "scanning" (at least with passive sensors, that is). The detection throw represents the sensor operator reading and interpreting the data (and he can focus his attention on close range data, short range data, or long range data).
RULE: The Detection Throw is made by rolling the ship's computer model number or less. A single die, or two or more dice, may be used on the throw, depending on the type of scan being performed. The sensor operator's skill level is used as a DM to decrease the throw and make success more likely.
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">Scan Type Number of Dice
----------------- ---------------
Close Range Scan 1D
Short Range Scan 1D
Long Range Scan 2D</pre>[/QUOTE]RULE: All Close Range scans are performed using a -4 DM. All Short Range scans are made throwing the single die with any applicable DMs. All Long Range scans are made by throwing two dice with any applicable DMs.
Vessels that use M-Drives, transponders, or active sensors are considered "active" targets and thus a -4DM is appropriate when scanning for such vessels.
Sensor operators can attempt to stretch the sensing capability of the ship's sensors by making an expert educated guess at data coming in from beyond long range. This procedure adds one light-second (300,000 km) to the vessel's long range limit, and the scan is performed by throwing 3D for the ship's computer model or less, using any appropriate DMs.
There is ample time during the 1000 second round of Book 2 space combat for the ship's navigator to conduct all four scans. Scans are performed during the ship's movement phase either before or after movement has been completed.
Game masters may implement other DMs to the detection throw based on special circumstances occurring in a scenario.
The maximum DM used on any Detection Throw is a -4 DM. The only modifier that can extend this DM greater than -4 is the sensor operator's skill.
Thus, a sensor operator with Navigation-2 on a vessel with a standard grade sensor package and a Model 2 computer will throw 1D -4 for 2- on Close Range scans, 1D -2 for 2- on Short Range scans, and 2D -2 for 2- on Long Range scans. A scan for targets out at Very Long Range will be performed by throwing 3D -2 for 2-.
By comparison, a sensor operator on this same vessel with Navigation-5 will throw 1D -5 for Close Range scans, 1D -5 for Short Range Scans, 2D -5 for Long Range scans, and 3D -5 for Very Long Range scans.
-HIGH GUARD-
These sensor rules can be used with ship designs from either Book 2 or Book 5. If using the High Guard combat system, consider vessels at the High Guard combat range of Short to be at a distance of five light-seconds or less (0 to 1.5 million km). High Guard Long range is equivalent to 5-15 light-seconds (1.5 to 4.5 million km). These High Guard distances are published in Mayday with the attempt being made to put actual ranges to the abstract distances used in Book 5 space combat. These combat ranges reflect the idea that combat between large capital ships will typically be conducted at high-G velocity. If these sensor rules are used with High Guard combat, allow Detection throws for vessels with military grade sensor packages only (standard grade packages do not have the range for this type of encounter). Targets at Long combat range can be tracked but not detected. Targets at Short combat range can be detected using the throw for a Long Range scan (Short combat range = Long sensor range). Vessels that have matched vectors are considered at Close sensor range. Craft with standard grade sensor packages can receive signal handoffs from friendly vessels with military grade sensors.
Since the Book 5 combat ranges are abstract, a GM may alter the combat ranges listed above for High Guard combat, making them shorter distances, so that standard sensor packages may be used.
-MORE DETAIL-
I've written some more detailed sensor rules for Book 2 combat that can be viewed HERE, but I'm keen to go with the less complicated method presented here (not that the other sensor rules are all that complicated to begin with) in my home game.
I find that these rules are easy to use during a Classic Traveller game (simply roll computer model number or less), and that detection is almost automatic within effective range unless the GM applies modifiers (as in trying to detect a signature from a ship anchored to an asteroid). The "automatic" nature of the detection roll lends itself well to Classic Traveller canon sensors (that is...that everything is detected out to a certain range).
When using these rules, don't forget to apply the range modifiers listed at the top of this post (from pg. 76 of The Traveller Book).
-OPTIONAL DETECT PROGRAM-
The Detect program increases the ship's computer's ability to filter readings and provide viable data for the sensor operator. The program will provide computer augmented "guesses" in attempts to aid the sensor operator with probably readings. Detect-1 will provide a -1 DM when making sensor scans. Detect-2 will provide a -2 DM, and so on.
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">Program Space MCr
-------- ------ ---
Detect-1 1 2
Detect-2 2 4
Detect-3 3 6
Detect-4 4 8
Detect-5 5 10</pre>[/QUOTE].
-OPTIONAL TARGETING RULE-
In the standard rules above, all targets that have been detected may be fired upon during a space combat round. Under this optional rule, a ship may only obtain a sensor lock (needed for targeting) on a number of targets equal to the ship's computer model number. All detected bogeys remain detected, but only those that are "locked" may be fired at with ship's weapons.
Using this rule makes these sensor rules a bit more useful. By design, these rules are not needed in many encounters. Unless the GM places a pretty hefty modifier on the detection of targets, most bogeys will be tracked in short order. By implementing this targeting rule, all detected bogeys are tracked for position but cannot be fired upon unless a sensor lock is obatained as well.
A sensor lock is obtained on a target the first time it is detected, and it remains "locked" until the sensor operator decides to break that lock (or the target moves more than 3 light-seconds from the ship). Detected bogeys can be reacquired as target locks simply by making the Detection throw against them.
-OPTIONAL SIGNAL QUALITY RULE-
GMs can use the result of the Detection throw to measure the quality of the signal lock or the quality of the sensor operator's interpretation of the data. Most times, the result of the Detection throw will be 0, and this indicates 0% margin of error. When the result of the Detection throw is 1 or higher (and still equal to lower than the computer's model number), GMs can use that result to guage the quality of of the scan. This would primarily be used for roleplaying purposes (not space combat).
-------------------------------------------------
Example
The ADROIT PURSUIT is a Type A2 Far Trader with a Model 1bis computer system and a standard grade sensor package. Her navigator is Luukhan Pershiire, skilled with Navigation-2 expertise. During the PURSUIT's movement phase of Book 2 space combat, her computer is running these programs: Maneuver (space 1), Target (space 1), Gunner Ineract (space 1), and Detect-1 (space 1).
One bogey has already been detected on a previous combat round, but Luukhan wishes to read the sensors this round to ensure the ship is not surprised later.
Luukhan will make all four sensor scans.
(Assuming any targets do not have tranponders broadcasting IDs and position or that any targets have gone "active". If so, the DM increases to -4 DM on the Short Range and greater scans.)
The Close Range scan is performed by Luukhan rolling 1D -4 for 1-. On this scan, Luukhan will interpret data from the area of 100,000 km around the ship.
The Short Range scan is thrown by rolling 1D -3 for 1-. This scan will allow Luukahn to interpret data in a sphere around the ship to a distance of 150,000 km.
The Long Range scan is performed by rolling 2D -3 for 1-. And, if Luukhan can make anything out of this data, it will result in detection of bogeys out to a distance of 300,000 km from the ship.
And, although close to impossible, Luukhan's Very Long Range scan will be performed by throwing 3D -3 for 1-. If successful, the scan will discover bogeys out to 600,000 km from the ship.
Any ship that is detected will remain detected (and "locked" for targeting purposes) as long as the vessel remains within 900,000 km of the PURSUIT.
If the optional targeting rule is used, then the PURSUIT can only "lock" one target at a time, but it can track all targets detected. This means a new sensor lock roll (the Detect roll thrown again for a known target) will be needed if the PURSUIT's gunner changes targets.
-AUTHOR'S NOTE-
Does all this look complicated? In actuality, players will throw 1D -4 or 2D -4 for the computer model number or less on most Detection throws. It's as simple as that--just one of those two throws. The bulk of these rules explain the "why's" rather than the "how's" of the system, and I've kept the system flexible should GMs wish to throw in modifiers for target size, stealth masking, M-Drive use, and the like. This extra detail is not necessary (which is why I didn't include it above, but the system can easily handle additional modifiers for things such as this). Range is always a funtion of the grade of the sensor package, and under these rules, there are only two grades of sensor: military and standard. Ideas for enhancing these sensor rules can be garnered by perusing THESE sensor rules I wrote last year.
-BASELINE-
From pg. 76 of The Traveller Book, under "Detection" ...Ordinary or commercial starships can detect other ships out to a range of about one-half light-second (about 150,000 km). Military and scout starships have detection ranges out to two light-seconds (600,000 km).
Ships which are maintaining complete silence cannot be detected at distances of greater than half dectection range; ships in orbit around a world and also maintaining complete silence cannot be detected at distances greater than 1/8 detection range. Planetary masses and stars will completely conceal a ship from detection.
From pg. 76 of The Traveller Book, under "Tracking" ...Once a vessel has been detected, it can be tracked by anyone up to three light-seconds (about 900,000 km).
From pg. 57 of The Traveller Book, under "The Bridge" ...Basic controls, communications equipment, avionics, scanners, detectors, sensors, and other equipment for proper operation of the ship are included in the cost and tonnage allocation of the vessel's bridge.
-SENSORS-
Space is vast, almost entirely empty and very, very cold such that even gases freeze solid. A ship's drives have to emit a lot of energy to provide any reasonable thrust, so the energy from a manuvering ship is very easy to detect against the super-cold background of space.
Even if a ship turns off its drives, it has to maintain a reasonable internal temperature for its crew; it contains a power plant which has to power a lot of electrical equipment (life support, computers, etc.). These systems all emit heat (as a waste by-product) which must be shed from the ship to prevent it building up and cooking the crew. Even a carefully contructed 'stealthy' ship must find a way to get rid of this energy, and can therefore be detected using the advanced sensors available in Known Space.
It is generally pretty easy to detect the presence of other starships and extact a fair amount of information as to the ship's type and status, based on its energy emissions.
The filtering of background noise is the limiting factor with modern sensor systems, and a ship's ability to filter electromagnetic energy emitted from a gas giant or background radiation from a system's star is directly related to the quality and capability of the ship's computer and sensor operator.
-SENSOR GRADE-
Sensors come as either standard grade or military grade equipment. Both grades include various active and passive sensors, but specific sensor type and operational parameters are not distinguished in these rules other than to say that military grade sensors are about four times as senstive as standard grade packages.
Military grade sensors are typically restricted and unavailable to those vessels built outside of a military organization, but exceptions do exist (at the choice of the GM). Scout craft typically employ military grade equipment.
-TRANSPONDERS-
By Imperial Law, transponders continually broadcast a vessel's ID and relevant information. When a ship emerges from J-Space, it is bombarded by multiple contacts in a busy system--the transponder signals broadcasting ID and current position of each vessel.
Military vessels have transponders that can be adjusted to broadcast altered ID information. They also have the ability to cease transponder transmission all together. But, all civilian ships must incorporate a transponder that constantly broadcasts and cannot be silenced.
Of course, the military grade transponders find their way to the grey and black market, and they can be had for a price. The penalty for being caught with such a device is high and can include imprisonment or forfeiture of the ship (or both). Transponder inspections are common as part of IAP (incoming-arrival procedure) with many worlds in the Imperium. One would think that corsairs with such a transponder would have an edge over the civilian traffic the pirates prey upon, and in some respects, this does pose a problem to civilian traffic. But, a ship approaching without a transponder broadcast can be blasted from the sky without warning--it being perfectly legal to do so. Corsairs have learned to be more crafty, either by broadcasting a false signal or finding position on a vessel by hiding behind a moon/planet/asteroid/satellite in space, and wounded corsairs find the number of ports where they can make port sparse as officials have to be paid to look the other way.
RULE: A -4DM is applied to the detection roll of any vessel broadcasting transponder ID.
-SENSOR OPS-
Sensor Operation is the skill associated with operating the ship's sensors and interpreting it's readings. Several Traveller skills provide expertise in Sensor Ops. GMs may wish to replace skills on character generation tables with the Sensor Ops skill.
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">Skill Sensor Ops
------------ -------------------------
Navigation at same skill level
Pilot at skill minus one level
Ship's Boat at skill minus one level
Gunner at skill minus two levels
Recon at skill minus one level
Survey at same skill level</pre>[/QUOTE].
-SENSOR RANGE-
Sensor range is variable and reliant on a number of factors. Under these rules, sensor grade determines its range. The table provides sensor range in light-seconds and kilometers.
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">Sensor Package Close/Short/Long Close/Short/Long
--------------- ------------------ ------------------
Standard Grade 0.33/0.50/1.00 LS 100K/150K/300K km
Military Grade 1.00/2.00/3.00 LS 300K/600K/900K km</pre>[/QUOTE]Each listed range is a distance from the ship measured in all directions. For example, a standard grade sensor performs a close range scan on everything within 100,000 km of the ship. At short range, the scan is a sphere, centering on the ship, scanning 150,000 km in all directions. Long range scans stretch out to one light-second (300,000 km) in all directions.
-DETECTION THROW-
Ship's sensors are operated by focusing them on one of the three ranges indicated in the chart above: Close Range Scan; Short Range Scan; Long Range Scan. A separate throw is needed for each scan. In actuality, the ship's sensors are constantly "scanning" (at least with passive sensors, that is). The detection throw represents the sensor operator reading and interpreting the data (and he can focus his attention on close range data, short range data, or long range data).
RULE: The Detection Throw is made by rolling the ship's computer model number or less. A single die, or two or more dice, may be used on the throw, depending on the type of scan being performed. The sensor operator's skill level is used as a DM to decrease the throw and make success more likely.
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">Scan Type Number of Dice
----------------- ---------------
Close Range Scan 1D
Short Range Scan 1D
Long Range Scan 2D</pre>[/QUOTE]RULE: All Close Range scans are performed using a -4 DM. All Short Range scans are made throwing the single die with any applicable DMs. All Long Range scans are made by throwing two dice with any applicable DMs.
Vessels that use M-Drives, transponders, or active sensors are considered "active" targets and thus a -4DM is appropriate when scanning for such vessels.
Sensor operators can attempt to stretch the sensing capability of the ship's sensors by making an expert educated guess at data coming in from beyond long range. This procedure adds one light-second (300,000 km) to the vessel's long range limit, and the scan is performed by throwing 3D for the ship's computer model or less, using any appropriate DMs.
There is ample time during the 1000 second round of Book 2 space combat for the ship's navigator to conduct all four scans. Scans are performed during the ship's movement phase either before or after movement has been completed.
Game masters may implement other DMs to the detection throw based on special circumstances occurring in a scenario.
The maximum DM used on any Detection Throw is a -4 DM. The only modifier that can extend this DM greater than -4 is the sensor operator's skill.
Thus, a sensor operator with Navigation-2 on a vessel with a standard grade sensor package and a Model 2 computer will throw 1D -4 for 2- on Close Range scans, 1D -2 for 2- on Short Range scans, and 2D -2 for 2- on Long Range scans. A scan for targets out at Very Long Range will be performed by throwing 3D -2 for 2-.
By comparison, a sensor operator on this same vessel with Navigation-5 will throw 1D -5 for Close Range scans, 1D -5 for Short Range Scans, 2D -5 for Long Range scans, and 3D -5 for Very Long Range scans.
-HIGH GUARD-
These sensor rules can be used with ship designs from either Book 2 or Book 5. If using the High Guard combat system, consider vessels at the High Guard combat range of Short to be at a distance of five light-seconds or less (0 to 1.5 million km). High Guard Long range is equivalent to 5-15 light-seconds (1.5 to 4.5 million km). These High Guard distances are published in Mayday with the attempt being made to put actual ranges to the abstract distances used in Book 5 space combat. These combat ranges reflect the idea that combat between large capital ships will typically be conducted at high-G velocity. If these sensor rules are used with High Guard combat, allow Detection throws for vessels with military grade sensor packages only (standard grade packages do not have the range for this type of encounter). Targets at Long combat range can be tracked but not detected. Targets at Short combat range can be detected using the throw for a Long Range scan (Short combat range = Long sensor range). Vessels that have matched vectors are considered at Close sensor range. Craft with standard grade sensor packages can receive signal handoffs from friendly vessels with military grade sensors.
Since the Book 5 combat ranges are abstract, a GM may alter the combat ranges listed above for High Guard combat, making them shorter distances, so that standard sensor packages may be used.
-MORE DETAIL-
I've written some more detailed sensor rules for Book 2 combat that can be viewed HERE, but I'm keen to go with the less complicated method presented here (not that the other sensor rules are all that complicated to begin with) in my home game.
I find that these rules are easy to use during a Classic Traveller game (simply roll computer model number or less), and that detection is almost automatic within effective range unless the GM applies modifiers (as in trying to detect a signature from a ship anchored to an asteroid). The "automatic" nature of the detection roll lends itself well to Classic Traveller canon sensors (that is...that everything is detected out to a certain range).
When using these rules, don't forget to apply the range modifiers listed at the top of this post (from pg. 76 of The Traveller Book).
-OPTIONAL DETECT PROGRAM-
The Detect program increases the ship's computer's ability to filter readings and provide viable data for the sensor operator. The program will provide computer augmented "guesses" in attempts to aid the sensor operator with probably readings. Detect-1 will provide a -1 DM when making sensor scans. Detect-2 will provide a -2 DM, and so on.
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">Program Space MCr
-------- ------ ---
Detect-1 1 2
Detect-2 2 4
Detect-3 3 6
Detect-4 4 8
Detect-5 5 10</pre>[/QUOTE].
-OPTIONAL TARGETING RULE-
In the standard rules above, all targets that have been detected may be fired upon during a space combat round. Under this optional rule, a ship may only obtain a sensor lock (needed for targeting) on a number of targets equal to the ship's computer model number. All detected bogeys remain detected, but only those that are "locked" may be fired at with ship's weapons.
Using this rule makes these sensor rules a bit more useful. By design, these rules are not needed in many encounters. Unless the GM places a pretty hefty modifier on the detection of targets, most bogeys will be tracked in short order. By implementing this targeting rule, all detected bogeys are tracked for position but cannot be fired upon unless a sensor lock is obatained as well.
A sensor lock is obtained on a target the first time it is detected, and it remains "locked" until the sensor operator decides to break that lock (or the target moves more than 3 light-seconds from the ship). Detected bogeys can be reacquired as target locks simply by making the Detection throw against them.
-OPTIONAL SIGNAL QUALITY RULE-
GMs can use the result of the Detection throw to measure the quality of the signal lock or the quality of the sensor operator's interpretation of the data. Most times, the result of the Detection throw will be 0, and this indicates 0% margin of error. When the result of the Detection throw is 1 or higher (and still equal to lower than the computer's model number), GMs can use that result to guage the quality of of the scan. This would primarily be used for roleplaying purposes (not space combat).
-------------------------------------------------
Example
The ADROIT PURSUIT is a Type A2 Far Trader with a Model 1bis computer system and a standard grade sensor package. Her navigator is Luukhan Pershiire, skilled with Navigation-2 expertise. During the PURSUIT's movement phase of Book 2 space combat, her computer is running these programs: Maneuver (space 1), Target (space 1), Gunner Ineract (space 1), and Detect-1 (space 1).
One bogey has already been detected on a previous combat round, but Luukhan wishes to read the sensors this round to ensure the ship is not surprised later.
Luukhan will make all four sensor scans.
(Assuming any targets do not have tranponders broadcasting IDs and position or that any targets have gone "active". If so, the DM increases to -4 DM on the Short Range and greater scans.)
The Close Range scan is performed by Luukhan rolling 1D -4 for 1-. On this scan, Luukhan will interpret data from the area of 100,000 km around the ship.
The Short Range scan is thrown by rolling 1D -3 for 1-. This scan will allow Luukahn to interpret data in a sphere around the ship to a distance of 150,000 km.
The Long Range scan is performed by rolling 2D -3 for 1-. And, if Luukhan can make anything out of this data, it will result in detection of bogeys out to a distance of 300,000 km from the ship.
And, although close to impossible, Luukhan's Very Long Range scan will be performed by throwing 3D -3 for 1-. If successful, the scan will discover bogeys out to 600,000 km from the ship.
Any ship that is detected will remain detected (and "locked" for targeting purposes) as long as the vessel remains within 900,000 km of the PURSUIT.
If the optional targeting rule is used, then the PURSUIT can only "lock" one target at a time, but it can track all targets detected. This means a new sensor lock roll (the Detect roll thrown again for a known target) will be needed if the PURSUIT's gunner changes targets.
-AUTHOR'S NOTE-
Does all this look complicated? In actuality, players will throw 1D -4 or 2D -4 for the computer model number or less on most Detection throws. It's as simple as that--just one of those two throws. The bulk of these rules explain the "why's" rather than the "how's" of the system, and I've kept the system flexible should GMs wish to throw in modifiers for target size, stealth masking, M-Drive use, and the like. This extra detail is not necessary (which is why I didn't include it above, but the system can easily handle additional modifiers for things such as this). Range is always a funtion of the grade of the sensor package, and under these rules, there are only two grades of sensor: military and standard. Ideas for enhancing these sensor rules can be garnered by perusing THESE sensor rules I wrote last year.
