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Old 01-06-2011, 02:04 PM   #1
vicky_molokh
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Default [Spaceships] Heat Signature, Cloaking Device, and Stealth Hull

Greetings, all!

In preparation for my space campaign, I'm looking over how detection works. There are some things that look either unresolved, or at least not 'doubtless' even if RAW. Specifically:

What is the Heat Signature of a Hot Reactionless drive or Boost Drive? RAW mentions 'as a reaction drive' - how much is that?

Stealth Hull requires a signature of +4 or lower to affect the detection roll. At TL10 it gives -2(TL-6)==-8. Auxiliary power is a Signature of +3 anyway, unless one is willing to turn off life support (and active sensors, if it matters).

Cloaking Device (SS1:13) says it makes a ship 'invisible' to sensors, but that it can be seen if it fires weapons or uses a reaction drive. Detection mentions -10 (-4 if already detected (?)), and nothing about weapons affecting it. Should that be interpreted as Basic Set Invisibility until weapons/drives use?

Also, the device is energy-intensive, which likely requires having a Fusion or similar reactor active. This puts it at odds with the Stealth Hull, unless it reduces the signature. Nothing gives me reason to believe that it does except my personal idea of what seems sensible. So, if my idea is wrong and RAW is right, a Cloaking Device gives de-facto -20 to detection (negates Plain Sight, and gives -10), plus 5 or more for the reactor. Stealth Hull, by comparison, provides de-facto -8, plus 3 unless one can ditch life support, but doesn't require a system slot, doesn't require power, cannot be disabled . . . but doesn't provide a penalty to being hit either.

Also, should Cloaking Device negate the Silhouetted Against Deep Space modifier (+24)? Again, no indication in RAW that it should, but my hunchy feeling says this isn't necessarily so. If it does, this makes the cloak much, much more desirable.

Answers? Opinions? Suggestions? Comments?
Thanks in advance!
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Old 01-06-2011, 02:58 PM   #2
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Default Re: [Spaceships] Heat Signature, Cloaking Device, and Stealth Hull

Heat signature: Hot says it has the signature of a conventional drive. The nearest match for thrust is something like an A-mat Plasma Torch, +10 signature. But it does seem either errata or that you're meant to pick the rating yourself to suit your setting.

Cloaking device: Silhouetted is cumulative with Plain Sight but Cloaking cancels Plain Sight: nothing to see (invisible), so no silhouette sounds logical. So does the "those stars just rippled" line of thought. But I'd go with the Star Trek version.
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Old 01-06-2011, 03:11 PM   #3
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Default Re: [Spaceships] Heat Signature, Cloaking Device, and Stealth Hull

I wouldn't allow cloaking devices to eliminate the plain sight bonus.

EDIT: Nevermind, I was thinking of the "silhouetted against deep space" bonus. I wouldn't allow it to negate that.

AM Plasma Torch or Total Conversion Torch have +10 or +11 to detect respectively and the same accel as the hot reactionless, I'd pick whichever number you like the best.

For getting both stealth hull and cloaking device on the same ship, you could use a system of solar panels. But basically a realistic stealth hull is only handy if you're not radiating like a small star.
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Old 08-25-2015, 08:47 AM   #4
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Default Re: [Spaceships] Heat Signature, Cloaking Device, and Stealth Hull

This seems the best place to ask (hence my sinister necromancy): Does a Stealth Hull and Cloaking actually stealth? Can you be more invisible than invisible? Super-extra invisible?

I originally thought they could be, but now I wonder. Cloaking seems to imply the maximum possible penalty (you're invisible), but not only can TL 12 stealth hulls exceed that (-12), but it seems they can stack... for a -22 (plus eliminating the plain-sight bonus of +10, giving them effectively a -32 compared to the average ship). Which is fine... perhaps that's the intent, but I just thought I would clarify.

It seems like your spooky "submarine" ships need a stealth hull and some kind of low IR signature system, but while you can run a cloak on a warship, it's not really going to let you get the complete drop on him, especially as you get closer.
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Old 08-25-2015, 09:13 AM   #5
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Default Re: [Spaceships] Heat Signature, Cloaking Device, and Stealth Hull

At least for normal character-driven Stealth, Kromm said that the In Plain Sight bonus should not apply to a target that is trying to be stealthy in the first place. Not sure whether it's meant to work the same way with spaceships.
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Old 08-25-2015, 11:19 AM   #6
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Default Re: [Spaceships] Heat Signature, Cloaking Device, and Stealth Hull

It's probably worth considering that there ain't no stealth in space. I think the best way to represent that is to always apply the In Plain Sight bonus, no matter what the ship is trying to do.
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Old 08-25-2015, 11:26 AM   #7
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Default Re: [Spaceships] Heat Signature, Cloaking Device, and Stealth Hull

Quote:
Originally Posted by vicky_molokh View Post
At least for normal character-driven Stealth, Kromm said that the In Plain Sight bonus should not apply to a target that is trying to be stealthy in the first place. Not sure whether it's meant to work the same way with spaceships.
You can't really try to be stealthy in situations where there's absolutely no cover, so unless the ship is somewhere that cover exists (rings of Saturn, cinematic asteroid belt, etc), the in plain sight bonus would always apply. Though I'm not sure the bonuses are quite correct at the moment, I think spaceships may make detection range a bit too high (based on human visual sensitivity, sunlit target in space is about +25 total).
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Old 08-25-2015, 11:34 AM   #8
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Default Re: [Spaceships] Heat Signature, Cloaking Device, and Stealth Hull

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Originally Posted by Anthony View Post
You can't really try to be stealthy in situations where there's absolutely no cover, so unless the ship is somewhere that cover exists (rings of Saturn, cinematic asteroid belt, etc), the in plain sight bonus would always apply. Though I'm not sure the bonuses are quite correct at the moment, I think spaceships may make detection range a bit too high (based on human visual sensitivity, sunlit target in space is about +25 total).
Consider that main engines of the Space Shuttle were visible from Uranus with current technology, though. That range penalty is in the -70 to -75 range (didn't work it out exactly).
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Old 08-25-2015, 12:23 PM   #9
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Default Re: [Spaceships] Heat Signature, Cloaking Device, and Stealth Hull

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Originally Posted by Humabout View Post
It's probably worth considering that there ain't no stealth in space. I think the best way to represent that is to always apply the In Plain Sight bonus, no matter what the ship is trying to do.
Cloaked ships are certainly not in plain sight, nor are ships in cinematic asteroid belts or in cinematic nebulas. That's how I see it. "In plain sight" is when you're standing around in an open field, only all of space is an open field... except for those listed above. And someone who is invisible is probably not sufficiently obvious to get the "in plain sight" modifier.

Stealth hulls, though, certainly aren't good enough.
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Old 08-25-2015, 12:46 PM   #10
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Default Re: [Spaceships] Heat Signature, Cloaking Device, and Stealth Hull

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Originally Posted by Mailanka View Post
Cloaked ships are certainly not in plain sight, nor are ships in cinematic asteroid belts or in cinematic nebulas. That's how I see it. "In plain sight" is when you're standing around in an open field, only all of space is an open field... except for those listed above. And someone who is invisible is probably not sufficiently obvious to get the "in plain sight" modifier.

Stealth hulls, though, certainly aren't good enough.
My apologies. I was replying to Vicky's post. Specifically that a ship trying to be stealthy shouldn't be considered In Plain Sight. Removing plain sight bonuses for cloaked ships makes sense, since it seems to try to mimic the submarine feel.
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