Well, i was planing an space encounter where the players get jumped by some pirates. And i was trying to figure out how sensors work, and how I would approach detection or surpise.. and it makes no sense as the rules are written.

On page 227 there is a nice explanation of it how sensors allow you in passive mode to see anything within your range band. When I look up the sensor range of the pirate fighters, the sensor range is the same range as the primary weapons. In fact, the players ship which has better sensors would be able to detect the pirates in passive mode before the pirates detected them. Then all the players would need to do is "punch it" take 2 moves, and be at medium range and never have the encounter.

Secondly, lets say the players want to scan a planet from orbit for a crashed ship (Beyond the rim) with active sensors they could do it at medium range, only if they were outside the atmosphere. But would have to be in the atmosphere to use them on passive mode.

Lastly, how in the name of the force are you going to be able to fight against a Capital ship, when you cannot even SEE it with your sensors until you are just out of range of your weapons, but well within theirs? in fact according to the rules you wouldn't know there is a capital ship out there in space until you almost run into it, or it starts firing on you.

Honestly, i think I have to take some gameplay from the X-wing video games and use this (minus any jamming or stealth systems being used):

Unidentified contact: ship silhouette, and maybe hull type at Extreme range, or at 2 range bands further then your sensor range in passive, and 3 range bands further in Active.

Confirmed contact: as above, but also class of ship, and maybe IFF (identification friend or foe) information at long range, or 1 range band further then your sensor range in passive, or 2 range bands in active.

Identified contact: as above, but active weapons, shields, etc. At medium range, or one range band further in active mode.

Transponder information: at close range only. Ship registry, hull number, ownership, and active scan will allow for limited information on cargo and crew

Space is big, but space is also empty. Sensor-wise, imagine submarine sonar. If you go active (ping) you can detect enemies on passive, but they will all know where you are too. The general rules of thumb I go by are:

If a ship emits (comms, active sensors, etc.), you can detect it with passives.

If you go to active sensors, you will detect your immediate surroundings, but ships can detect you with their passives from farther away than you can detect them with actives.

According to rules Active sensors on work on a single "Arc" at one range band more then listed. But if you cannot even dected them on passives, how do you know which arc to use?

This is not sonar.

I ran across this same problem, so my immediate solution was a network of ancient satellite relays the pirates hacked into in order to scan the entirety of the Onderon system all at once. Bam! Done.

I don't have the book with me right now, but if I recall correctly then you automatically detect everything in a 360 degree sphere around your ship up to the sensors' range in passive. You can also go active, which only scans one arc but extends the sensor range by one band; this requires an Easy: Computers roll. You can just stick the pirates with at least one ship that has sensor range one band less than the PCs and have them run active scans, which means they would spot each other at the same time. Or have one pirate ship slightly in front of the others, thereby making the players think they have an easy fight on their hands and not giving them a reason to run.

I don't like the idea of being blind beyond your sensor range. It just does not make sense.

I don't recall reading anywhere that a ship is blind beyond its sensor range. The book seemed a little fuzzy on that.

The way I understand sensors is that it's all just a static-y soup from which a sensor operator divines structure and shape and energy signatures. One operator might see a fleet of pirates where another might detect only background noise.

The way I'd handle it is to have active scans increase in difficulty with each range band beyond the ship's base sensor range and then things like gas clouds and asteroid fields can increase the difficulty further. Successes will identify a "something" out there, Advantages and Triumphs can add details, and Threats and Despairs can throw false information.

According to rules Active sensors on work on a single "Arc" at one range band more then listed. But if you cannot even dected them on passives, how do you know which arc to use?

I think one of the purposes of Active sensors is to sweep each arc in turn in order to detect enemies before they reach passive range. As you've pointed out, passive range is usually weapon range on most ships. I think passive mode is really just there for the targeting computers to do their thing. Active mode is where sensor operators ought to be focusing their time and Computer checks.

Remember, too, that this is a narrative tool, not a mechanical one.

You wouldn't have the players make Perception checks to detect each combatant on a battlefield. Likewise, you should only bring sensors into play when the dramatic nature of the encounter calls for it.

If the circumstances of the encounter require that the PCs detect a fleet of Imperials at Extreme range, then just tell the players that the sensors pick up a fleet of Imperials at Extreme range.

Maybe a solid house rule to counteract this blindness is that "The listed sensor range refers to the maximum distance at which the ship can detect an object of equal size. For each silhouette larger the object being detected is than the ship who is trying to detect it, the detecting ship's sensor range is considered one Range Band longer." Or something like that. It maintains the ability for fighters to be practically on top of you before they're spotted, but gets rid of the problem that you can be shot by a capital ship that's too far away to even see.

I generally hand wave sensors unless it's a plot issue (ie: need to figure out what exactly type of ship there are or try to scan for life forms). I've been reading a lot of the x-wing books and I generally go by the sensors there, which is that they can detect ships from *very* far away. The exact type and number of ships might need some sensor (computers) rolls, with range and type of sensors being the difficulty and bonuses, but other than that I agree that the rules as written just don't make sense.

I get having range close for firing say the quad blasters on the YT-1300, but they could literally see the ships fly past visually at that range - you're telling me standard sensors are just as good as your eyes? Why not just have a guy with a vaccuum suit on top of a pole attached to your ship, ala a naval ship from the 1800's?

What's more fun, anyway?

"You drop out of hyperspace at extreme range from your asteroid base - you see flashes of light all around it. You receive a frantic transmission from your base crew saying they're under attack from pirates. As you close to long range you successfully roll against a hard computers check and are able detect 4 starfighters strafing the base backed by a scout ship. Your advantages on the roll allow you to detect a larger freighter slipping into an undefended hangar bay. Pushing shields forward, you and your ship take 2 strain and you punch your ship into it's highest speed, heading directly toward the ships."

or

"You drop out of hyperspace and receive a frantic transmission from your base crew saying they're under attack from pirates. You turn your sensors towards your base but detect nothing until you reach short range. You head towards it and when you get into attack range you see a group of pirates."

Whatever you decide to do, just be sure to include "That's no moon!" while you're narrating the scene to the PCs, this is vitally important!

I generally hand wave sensors unless it's a plot issue (ie: need to figure out what exactly type of ship there are or try to scan for life forms). I've been reading a lot of the x-wing books and I generally go by the sensors there, which is that they can detect ships from *very* far away. The exact type and number of ships might need some sensor (computers) rolls, with range and type of sensors being the difficulty and bonuses, but other than that I agree that the rules as written just don't make sense.

I get having range close for firing say the quad blasters on the YT-1300, but they could literally see the ships fly past visually at that range - you're telling me standard sensors are just as good as your eyes? Why not just have a guy with a vaccuum suit on top of a pole attached to your ship, ala a naval ship from the 1800's?

What's more fun, anyway?

"You drop out of hyperspace at extreme range from your asteroid base - you see flashes of light all around it. You receive a frantic transmission from your base crew saying they're under attack from pirates. As you close to long range you successfully roll against a hard computers check and are able detect 4 starfighters strafing the base backed by a scout ship. Your advantages on the roll allow you to detect a larger freighter slipping into an undefended hangar bay. Pushing shields forward, you and your ship take 2 strain and you punch your ship into it's highest speed, heading directly toward the ships."

or

"You drop out of hyperspace and receive a frantic transmission from your base crew saying they're under attack from pirates. You turn your sensors towards your base but detect nothing until you reach short range. You head towards it and when you get into attack range you see a group of pirates."

I think the intent was not numbers and general category. If you look at the actions in the piloting section it talks about reading very fine detail such as attachments, armaments, and mods.

Great bit of narration there by the way.

As for being worried that passive sensors will automatically detect the pirates, also keep in mind that even if the sensors pick them up, that doesn't help anyone if nobody's keeping an eye on the sensor monitor!

I would think pirates would have some way of jamming enemy sensors.

I don't like the idea of being blind beyond your sensor range. It just does not make sense.

I'm not trying to be a jerk, by why?

Is it that in the films everything seems to take place within visual range? I'd call that Short range, really, given the stats of the weapons they use.

Passive sensors don't send signals out, so they themselves are pretty much undetectable. Active sensors would be stuff like lidar . Active sensors would be detectable by passive because they're sending crap into your volume of space. You'd even be able to tell the direction (though not the distance) the beam came from.

If you look at the targeting jammer suite, it notifies everything within a star system of its presence.

I'd also say that anything outside sensor range can be detected, but only silhouette and general location, i.e. distance/range band, and if it is active in some way, or the sensor operator is actively searching the system. Any movement requires tracking over rounds if outside range. Once within range useful information can be gleaned using sensors.

I simply use different scales for Communication/Sensor ranges and Weapon ranges.

In my game Communications and Sensors use a "long" space range (the simple "Close" subspace transceiver of an X-Wing can quickly reach distances of 25 light years if not interrupted and the Rebel base on Hoth and the Imperial fleet outside the system were able to detect and scan each other before the fleet had dropped out of hyperspace), while Weapons use a "short" space range.

I don't like the idea of being blind beyond your sensor range. It just does not make sense.

You might want to make exceptions based on the size of what you are looking for. Planets and large star ships might be easier to spot. But figuring out exactly what it is might be hard or impossible.

FYI it is impossible to use sonar to locate submarines. Sonar doesn't work. Unless... You determine the thermal saline profile of that section of the ocean. Subs can hide at depths that active sonar is naturally deflected from. In fact data was gathered on ocean thermal saline profiles by all combined allied navies since the 60's, and is the basis of much of our understanding of Global Warming.

Back to the post, maybe it's time our ships started hiding in the planetary Magnetic Heliospheres (black dice against detection) when they roll a few lucky charms on piloting...

If you want to know what would be detection in space, read no further: Project Rho

I agree with LukeZZ. It seems like the rulebook failed to indicate that weapons range and sensor range are different scales. That's the only explanation I can see.

My best guess is to use:

Weapons Range - Close - Short - Medium - Long - Extreme - XX

Sensors Range - Close -Close - Close - Short - Short - Medium - Medium - ...

Even tough I think that the detection should be related to ship size, not these bands. The larger the ship, the farther it can be detected from.

Sensors should have quality (1-4 blue dice), where

0 the Mk1 eye-ball,

1 basic sensors (transports, non military)

2 advanced sensors (old fighters, upgraded transports)

3 military sensors (new fighters, old military capital ships)

4 dedicated military sensor array (new military capital ships)

Sensor Range [not weapons range]

Close - 1 purple (planetary)

Short - 2 purple (far orbit)

Medium - 3 purple (50,000 km)

Long - 4 purple (interplanetary 3AU)

Extreme - 5 purple (out system 30AU)

Skill

Computer skill

Upgrades the computer skill for Size/2(?) (round up) times the smallest ship on that range to be detected is. If the smallest ship is detected, all larger ships are detected as well. Sure, check for appropriate conditions.

Jamming, stealth, obstructions (black dice)

1 - minor obstruction, asteroid field, nebulae, basic sensor jamming

2 - major obstruction, behind a rocky planet, advanced sensor jamming

3 - using a gas giant for cover, stealth device

4 - using a star for cover.

5 - using a black hole for cover (!)

What do you guys think?

Cheers,

Whatever you decide to do, just be sure to include "That's no moon!" while you're narrating the scene to the PCs, this is vitally important!

Recent example of how I use sensors:

The PCs were leaving Geonosis with a cargo of Geonosian blaster rifles and pirates were laying in wait in the asteroid field around the planet. I had the sensor op/co-pilot roll a Computers check vs. hard difficulty to detect the pirates. He failed thus the pirates "came out of nowhere" and attacked. The pilot continued to fly, while the co-pilot went to engineering and the other 2 crew members manned the guns. I ruled since no one had yet detected anything the gunners had no targets, they or the pilot needed to spend an action searching for what was out there.

I like:

Weapon Range: Close --- Short --- Med --- Long --- Extreme

Sensor Range: Close --- Close --- Short --- Short --- Medium --- Long --- Extreme

Something like a Cloakshape fighter (sensor range close) with missiles (range short) can only detect a ship when just in weapon range when actively scanning. Seems off. Adjustment above they could detect a ship a couple of combat range bands off of their max weapon range when actively scanning. Just seems like sensors should exceed installed weapons range, and for some ships in FFG rules they don't.

Not to derail this topic, but I also notice that with "Fly/Drive" maneuver, a speed 4 ship at Long range can never, ever close. Even against an entirely stationary enemy. Heck, even two speed 4 ships at Long range in a combat desperately flying towards each other will never reach one another.

It says two maneuvers to go from close-medium or from medium to close, but there is no getting to something at long range ever, apparently unless speed 5? Seems like maybe four maneuvers at speed x should get you one greater than the range band you can cross with two maneuvers or something.

Not to derail this topic, but I also notice that with "Fly/Drive" maneuver, a speed 4 ship at Long range can never, ever close. Even against an entirely stationary enemy. Heck, even two speed 4 ships at Long range in a combat desperately flying towards each other will never reach one another.

It says two maneuvers to go from close-medium or from medium to close, but there is no getting to something at long range ever, apparently unless speed 5? Seems like maybe four maneuvers at speed x should get you one greater than the range band you can cross with two maneuvers or something.

From the FAQ/Errata document for EotE:

PAGE 232

In the Fly/Drive entry, add the following sentence to the end of the paragraph: "Moving between one range band and the next always takes two maneuvers regardless of speed, with the following exceptions detailed below:"

In other words, two maneuvers at any speed will get you from one range band to the next. Faster speeds essentially let you move between range bands for fewer maneuvers as detailed in the book.

Not to derail this topic, but I also notice that with "Fly/Drive" maneuver, a speed 4 ship at Long range can never, ever close. Even against an entirely stationary enemy. Heck, even two speed 4 ships at Long range in a combat desperately flying towards each other will never reach one another.

It says two maneuvers to go from close-medium or from medium to close, but there is no getting to something at long range ever, apparently unless speed 5? Seems like maybe four maneuvers at speed x should get you one greater than the range band you can cross with two maneuvers or something.

From the FAQ/Errata document for EotE:

PAGE 232

In the Fly/Drive entry, add the following sentence to the end of the paragraph: "Moving between one range band and the next always takes two maneuvers regardless of speed, with the following exceptions detailed below:"

In other words, two maneuvers at any speed will get you from one range band to the next. Faster speeds essentially let you move between range bands for fewer maneuvers as detailed in the book.

Thanks! I need to go through that errata more carefully.

In general I like Wowsky's rough suggested detection rule. In a game where sneaking around in trapped dungeons is common, you want some mechanics for moving silently, hiding in shadows, picking locks, etc. Similarly in EoE, sneaking around avoiding the Empire seems likely to be a common thing, so having some mechanics for it for the players to strategize around seems like a good idea.