Vision penalties per yard?

[raniE]

So, Ultra-Tech page 114 mentions that in the case of haze, rain, smoke, etc, tha target of a high-energy laser attack gets DR equal to the vision penalty in yards. Now, where can I find examples of such vision penalties, especially for atmospheric conditions (I'm guessing the smoke penalties listed under smoke grneades and such are per yard). Are they in the Basic Set, because I can't find anything about vision penalties except for darkness and Obscure, neither of which seems to be per yard, and don't help me much with atmospheric conitions like rain anyway.

[Stripe]

Hmm... I'm not sure either. In for the answer.

Page 548: "Partial darkness, fog, smoke, etc.: -1 to -9 (GM’s option)"

[raniE]

Originally Posted by Stripe

Hmm... I'm not sure either. In for the answer.

Page 548: "Partial darkness, fog, smoke, etc.: -1 to -9 (GM’s option)"

Yeah but that doesn' give me any particular help in determining how bad the penalty should be, and I'm not familiar enough with high-powered laser systems to eyeball it.

[Ts_]

I'll add a question ... What kind of vision penalty corresponds to what light source? There is something like this for hearing in the Basic Set on the Sense Rolls page, but I couldn't find anything for light. The framing is -10: pitch black and 0: daylight, I guess, and I don't feel bad about judging this on the fly, but I'm curious if someone has a nice list. This of course would also need to be adjusted for distance in some way (including smoke), with different rates of fall-off depending on what part of the sphere the light covers, the focusing etc (luckily there are not a lot of optical elements in a medieval torch or a camp fire).

Thanks!
Ts

[Langy]

I'd put 0 for normal interior lighting as well, which is significantly less bright than daylight. You just don't get a bonus for an area that's really bright until it gets so bright that you get a penalty.

[Anaraxes]

Perhaps Anthony will post his house rules on a non-geocities web page. I can't find that even at archive.org now.

[SCAR]

GURPS Mysteries has some Sense Roll Modifier Tables including Darkness Modifiers (p47) covers the full 0 to -9 range.

The 3e to 4e Conversion changes Smoke to Obscure (Vision) 10, which would equate to a -10 vision penalty.

Otherwise you're mostly looking at GM's option as listed in Basic!

[cccwebs]

Originally Posted by raniE

So, Ultra-Tech page 114 mentions that in the case of haze, rain, smoke, etc, tha target of a high-energy laser attack gets DR equal to the vision penalty in yards. Now, where can I find examples of such vision penalties, especially for atmospheric conditions (I'm guessing the smoke penalties listed under smoke grneades and such are per yard). Are they in the Basic Set, because I can't find anything about vision penalties except for darkness and Obscure, neither of which seems to be per yard, and don't help me much with atmospheric conitions like rain anyway.

Use the range penalty (from size/speed/range table) but only include the portion of the distance covered by the situation. ie, firing the high-energy laser in the rain at a target 100 yds away, the target would have an additional DR of 10

edit - above fnorded out because I should really wake up before responding to a post.

[munin]

It's the vision modifier of the obscurement, not the vision modifier due to range:

"Rain, fog, smoke, snow, and similar weather or atmospheric conditions interfere with all high-energy lasers, adding extra DR to the target equal to the vision penalty (per yard). Thus, if a yard of smoke would be -10 to vision, then each yard gives DR 10; if every 100 yards of haze gives -1 to vision, then 1,000 yards provides DR 10." (p. UT114)

So: haze (-1/yard), smoke (-10/yard).

I'd just break it into three categories and call it a day: light obscurement (1 DR/yard), moderate obscurement (3-5 DR/yard), heavy obscurement (10 DR/yard).

[Anthony]

Originally Posted by Anaraxes

Perhaps Anthony will post his house rules on a non-geocities web page. I can't find that even at archive.org now.

It's now at http://sites.google.com/site/anthonysgurps/lightdark, but doesn't contain useful data for this situation. Atmospheric haze is typically given a visibility, which is a distance (specifically, it's the distance at which 95% of contrast is lost). That distance is probably around a -8 modifier in GURPS (if we're following the same log scale as everything else), so you get a -1 per (visibility/8) distance. Based on the wikipedia numbers, typical fog is going to be a vision penalty ranging from -1 to -9 per hundred yards, and the DR is equal to the vision penalty (the rules in UT are unnecessarily complex).