[Enhanced Senses] Darkness, Night Vision, and flickering

Strabo · 11-15-2023, 05:20 AM

I’ve been trying to figure out how light and darkness work in GURPS for a long time. I did my due diligence, and I am content with the illumination levels table from page 13 of GURPS Enhanced Senses (version 1.1, not 1.0). However, there are some parts of the rules that are little bit unclear to me, and I’d greatly appreciate if somebody would shine some light on them. I feel that light and darkness are very important rules, and since they come up very often, it’s nice to have consistent and clear rules.

1. GURPS Powers: Enhanced Senses says that torch is equivalent to an illumination level of -1. In Basic Set, it is -3, in Template Toolkit 2: Races it is -2, in DF it is 0. Enhanced Senses, however, mentions that flickering lights add another -1 to -3. Is this flickering penalty taken into account in the table? I mean, does -1 mean (0 illumination with -1 for flickering), or should this penalty be applied to this -1? That would bring the torch down to -2, -3, or -4 (two of which correspond to torchlight intensity from other sources).
2. “A light source in a dark environment eliminates or reduces Vision penalties within the illuminated area but *prevents* seeing outside it. Treat the light as “in plain sight” to distant observers who have a clear view of it: +10 to Vision rolls to notice the lighted area (p. B358). However, they’re at ‑7 to see anything else.” This rule also exists in GURPS Underground Adventures, but is phrased slightly differently – “However, they’re at -7 to see anything outside its radius.”
This causes many questions, especially when multiple light sources are visible, and Night Vision is present. I drew a diagram that demonstrates the situation. I don’t know if it is correct. The ambient darkness penalty is -5, and there are two groups with torches, and some without torches.

Diagram link

3. “Prolonged exposure to intense light can cause lasting or permanent vision loss.” How long is prolonged?

11-15-2023, 05:20 AM	#1
Strabo Join Date: Jun 2012	[Enhanced Senses] Darkness, Night Vision, and flickering I’ve been trying to figure out how light and darkness work in GURPS for a long time. I did my due diligence, and I am content with the illumination levels table from page 13 of GURPS Enhanced Senses (version 1.1, not 1.0). However, there are some parts of the rules that are little bit unclear to me, and I’d greatly appreciate if somebody would shine some light on them. I feel that light and darkness are very important rules, and since they come up very often, it’s nice to have consistent and clear rules. 1. GURPS Powers: Enhanced Senses says that torch is equivalent to an illumination level of -1. In Basic Set, it is -3, in Template Toolkit 2: Races it is -2, in DF it is 0. Enhanced Senses, however, mentions that flickering lights add another -1 to -3. Is this flickering penalty taken into account in the table? I mean, does -1 mean (0 illumination with -1 for flickering), or should this penalty be applied to this -1? That would bring the torch down to -2, -3, or -4 (two of which correspond to torchlight intensity from other sources). 2. “A light source in a dark environment eliminates or reduces Vision penalties within the illuminated area but prevents seeing outside it. Treat the light as “in plain sight” to distant observers who have a clear view of it: +10 to Vision rolls to notice the lighted area (p. B358). However, they’re at ‑7 to see anything else.” This rule also exists in GURPS Underground Adventures, but is phrased slightly differently – “However, they’re at -7 to see anything outside its radius.” This causes many questions, especially when multiple light sources are visible, and Night Vision is present. I drew a diagram that demonstrates the situation. I don’t know if it is correct. The ambient darkness penalty is -5, and there are two groups with torches, and some without torches. Diagram link 3. “Prolonged exposure to intense light can cause lasting or permanent vision loss.” How long is prolonged?