Okay, most of my group has thermographic vision and, due in large part to the vague description in the core book I guess, my runners have taken it upon themselves to say the following: "Body heat is generally higher than room temperature so, with just my thermographic vision, I can see into a heavily tinted car and see figures and, if the walls are thin enough, inside a building." When they fail a perception test against stealth they also go, "I use thermographic vision, do I see him?" Realistically I made them roll versus his stealth but, what they're saying is, if he doesn't have thermal dampening, I can see him without rolling perception, especially if he's just up near a dumpster or laying out in tall grass." I kind of see their point but told them I wouldn't allow thermo to automatically see individuals because otherwise stealth is useless. Any thoughts? Thanks guys.

Thermographic will not see through anything.

Why? Because all thermographic is, is the detection of infrared radiation, rather than visible radiation, aka light. So if something that is opaque to the infrared is present between the source of the radiation and the sensor, the source is invisible.

Now, what that actually means is that anything solid, or liquid, between the person using stealth and the person looking around, will block thermographic vision.

Walls? Glass? Those absorb infrared radiation. For any to be radiated, a small area of the wall must be of a different temperature then the rest. Doesn't happen that way, so all you'd see is glass, or a wall. Or even tall grass.

What it does allow is you to see through things that are not dampened and are in physical contact with the person hiding. Skin contact heats things up, radiated heat doesn't. So, someone who is hiding under pillows, a grass matt, or cardboard boxes for any length of time, in rutheneum, and so on and so forth.

Edit: I'm simplifying things a bunch, admittedly. Someone standing near a plain glass window (completely uninsulated) for an hour would probably be visible to thermographic.. as a vague "slightly warmer" spot. And a rice sheet would probably work the same way.

Aside from the boot in the ass, explain to them how the visibility modifiers work. (sr3.112)

"Yeah, I already counted your thermographic vision when determining which visibility modifier to apply. See? It's full darkness, so I only added a... +2 to your target number to see the stealthed individual due to your thermographic vision."

When it comes to checking target numbers, generally, that's ALL thermographic/low light/etc vision does. Explain that to them. Then explain to them that stealth encompasses more than just hiding in the bloody shadows; it includes moving quietly, putting visual obstacles between you and the target, making yourself "small", etc.

What it boils down to is -- thermographic vision IS essentially light. It's just a spectrum that is generated by lower energy levels that isn't normally visible to humans. If something is totally opaque to normal vision, it's *probably* totally opaque to thermographic vision. If glass is designed to be one-way opaque, you can be sure it's opaque to thermographic vision -- metahumans have been around for *how* long? The exception is, as Dawnshadow mentioned, if the radiating object is hot enough and in proximity to the opaque surface long enough to raise the temperature of the opaque surface in any noticable fashion.

Also, why are you even letting them *know* they're rolling perception against stealth? That gives it away. Just write down their dice pool in advance, and roll it secretly. If they get any successes, then let them know. Otherwise, they should remain blissfully ignorant.

Thank you all for your help, especially Vaevictis for citing the corebook's visibility chart. I didn't even think to mention that because, well, I knew thermo would apply to darkness but I wasn't sure what else it could do. I thought they made it too strong. Thanks.

I like telling them they've failed their spot checks pretty regularly; waiting in line at the grocery, on a date with a lady, sitting on the can. Then, to make sure they know I'm not just making stuff up, ninjas who have been nesting on the roof of the bathroom drop down and kill them.

I will say that thermograpihc does add an additional ‘contrast filter’ to vision, so your camo clothing may not count as camo clothing vs thermographic as well. O course, any purpose built camo clothing of the age would also do some stuff to alter and disperse your thermal signature, or it would be pretty worthless.

The Stealth rolls encompasses many small details and actions. It is not simply bypassed by someone with appropriate vision mods. The Stealth roll represents quickly moving between cover, ducking out of sight, and the likes. It's not the computer game version where you press your "stealth" key, and if it's high enough you magically stay undetected while in plain sight.

Our (US Army) BDU's (and now ACU's) are treated to reduce IR signature, and anyone with a hundred bucks (or less depending on where you buy) can buy them new. I would assume that our Marines and even AF uniforms have this as well. I wonder why it's illegal to own them up north?

I've seen the new Canadian green uniform. It's pretty nifty.

Biker gangs were using them when they smuggled to avoid IR camera's that cops use a night.

Even ruthenium states that it is half effect if the observer has thermo vision.

Its all in there.

Edward

Which has what to do with...what?

Interesting about the biker gangs though.

Not to Canada bash, cause I like anyplace that can produce both Stargate SG-1 and Atlantis as well as the Red Green Show, but Canada is not the freedom loving state that the US tends to be. The Canadian Government is in many cases a communist like state, their laws are strict is several ways Americans find odd, like satelite dishes that bring in not state funded or approved channels (AKA Fox News Network), gun laws are different, as well as just about anything labled military in nature, however a woman can walk around topless, so I've got mixed feelings about the laws there...
Here in the US of A, it's pretty much fair game for non military (yes I know the assault weapon ban was a friggin joke as 4 flashlights strapped to a .22 calibre rat killer is now defined as an 'assault weapon') weapons, however many formerly military type items are for sale, like BDU's etc. (mainly cause after a wash or two they no longer hide the thermo radiation) and civies cannot easily get it reapplied yet we cannot show fake cartoon titties on public tv even at 3 in the morning when the kids have gone to sleep. again, I'm of mixed feelings with the laws here...

::sits back to watch the thread degenerate::

My apologies, didn't mean to do anything against TOS. Was just pointing out that open border <> same laws/policies/politcs/culture

... so, Thermal vision. Here's a thang, Radiated heat is not necessarily blocked by all materials, for example, UK bank notes have diffferent levels of transparentness to the IR spectrum on different parts of the note. This aids creatly in the production of bank note verification systems.

It is quite posible for certain substances to be opaque on the visible spectrum but fairly transparent to infra red radiation. Just like x rays can go through most low density non metallic materials.

This leads to cute tricks like hiding weapons turrets with IR sensors behind IR transparrent walls, thermal vision can't see them cos they are the same temperature as the surroundings, but they sure can see out.

As to how thermal vision affects stealth skill, wing it from the circumstances. Somebody hiding in a cardboard box for 20 mins would make it suspiciously hot, somebody ninjing it up behind you and thermal vision don't help any.