[Herr Brackhaus]

That's your interpretation of RAW, Marcus. Nowhere on the rules does it say that stacking is possible, so taking two separate effects and joining them is an interpretation, not RAW.

[Marcus Gideon]

That's been my point all along. Nowhere does it say they can stack, although nowhere does it say they can't either.

If the GM opts to let them stack, they are guaranteeing that their players will never need to worry about Light penalties.

Which is why I think it's far more fitting with the cinematic flair of the game, to make sure they don't stack.

[kyoto kid]

...as I recall, Tetrachromatic vision is a Genemod don't see how it would stack with cybereyes.

[Marcus Gideon]

You can get vision mods from a number of sources. Cyber Eyes, glasses / goggles / contact lenses, natural abilities.

[Rooks]

How does enhancing ambient light have any effect on thermographic vision, or vice versa?

At my table, no stacking allowed. I feel relatively confident that that is what the rules intend. YMMV, so ask your GM because the books won't tell you one way or another.

We usually rule no stacking either but its two different feeds super imposed into one so even if its total darkness you can use thermals but night vision isnt going to do anything because night vision (even from a technical stand point irl) needs a light source to create the night vision effect (thermalgraphic doesnt create light out of nothing, thats what a flashlight is for)

[Whiskeyjack]

That's your interpretation of RAW, Marcus. Nowhere on the rules does it say that stacking is possible, so taking two separate effects and joining them is an interpretation, not RAW.

This is a system where effects generally stack unless explicitly called out as not stacking.

[Herr Brackhaus]

That's a fair point, Whiskeyjack. I can't find anything that specifically calls out stacking vision enhancements either way.

[Marcus Gideon]

That's your interpretation of RAW, Marcus. Nowhere on the rules does it say that stacking is possible, so taking two separate effects and joining them is an interpretation, not RAW.

This is a system where effects generally stack unless explicitly called out as not stacking.

Which is why I have been explaining my reasoning for prohibiting stacking in that kind of instance.

The only time when both Thermo and Low-Light will both come into play, is a scene in Total Darkness.  Low-Light by itself says it automatically brings Dim or Partial all the way up to Full, so the only time it's useless is Total Darkness.

Going purely by game mechanics RAW, ignoring the cinematic description, Thermo brings it up 1 category from Total Darkness to Dim Light. At which point Low-Light takes over and improves it completely to Full. Thus negating the Light penalties entirely.

Cinematically however, a room in Total Darkness has absolutely zero ambient light, and switching to Thermo vision isn't going to create any light (aside from the display screen if you're using Goggles or something). So there still isn't any light for your Low-Light to amplify. Which means there is no cinematic justification for applying Low-Light.

So if you go by "allow stacking unless told otherwise" then adding Thermo + Low-Light = no Light penalties ever.

If you apply a teeny bit of logic and reason, then there's no way they would stack.

[Herr Brackhaus]

To be fair, if the character wants to get around that particular scenario, Marcus, all they need is a low-light flashlight and low-light vision, and they'll have no penalties. I agree 100% with not letting thermo and low-light vision stack because of the difference in technology, but ultimately it doesn't really matter as there are other, completely legal beyond any shadow of a doubt, ways of achieving the same effect.

[Strange]

As Marcus Gideon pointed out, this same discussion took place at the same time on another thread!  Very odd.  If you do a search, there are a couple of older threads about the vision enhancements stacking, too.  I agree that they should not stack, however, I think they should both be allowed to be on at the same time.  It actually exists today in that form, and I imagine it would have only become better.

[kyoto kid]

...getting back to the original question,  yeah the +3 bonus to visual Perception from the Tetrachromatic Vision genemod is still worth it for my character as neither BGC, noise, nor hacking, can interfere with it. 

[Rooks]

To be fair, if the character wants to get around that particular scenario, Marcus, all they need is a low-light flashlight and low-light vision, and they'll have no penalties. I agree 100% with not letting thermo and low-light vision stack because of the difference in technology, but ultimately it doesn't really matter as there are other, completely legal beyond any shadow of a doubt, ways of achieving the same effect.

Except if your opponent has low light vision as well then you stick out like someone wearing a miners hat

[FST_Gemstar]

I'll necro this post for a related question: 

Does Tetrachromatic Vision basically counteract the Night Blindness Quality?

Is it too cheap to pair therm?

[Hobbes]

As a GM I would ask the Player to pay off the Night Blindness quality if they take Tetrachromatic Vision.  Just like if they implanted Low Light vision, you've removed the Negative quality so you pay the Karma to remove it and carry on.

"...too cheap to pair them?"  By Cheap if you mean deliberately taking a Negative Quality that is then ignored by adding a piece of gear, then yes.  I would not allow it as a GM. 

[FST_Gemstar]

That's what I thought too.