[3.5] Ambient Light at Dawn and Dusk

[Maginomicon]

In the regular game I run it's important to keep track of exactly what time of day it is.

Is there something in the official rules for how to determine the ambient light level based on the time of day?

I was thinking that creatures and objects in what would usually be broad daylight would just progressively gain mundane concealment depending on the hour of the day, and this kind of concealment would stack with all other forms of concealment up to a limit of 50% (total concealment).

To keep it simple, I assume a 24-hour day in a middle lattitude in the spring and ignoring daylight savings. Naturally, changes to any of these factors would change the table's contents as-appropriate.
{table=head]Dawn Hours | Dusk Hours | Concealment
9 AM onward | before 6 PM | 0% |
8~8:59 AM | 6~5:59 PM | 5% |
7~7:59 AM | 7~6:59 PM | 10% |
6~6:59 AM | 8~7:59 PM | 15% |
before 6 AM | 9 PM onward | 20% |
[/table]

(NOTE: The nighttime hours assume clear starlight/moonlight, cloud cover or other mundane effects change the 20% line to something more up to a limit of 50%.)

(NOTE: The table's intentionally skewed to favor daylight hours because even the slightest sliver of sunlight at dawn or dusk causes us to have more daylight hours than nighttime hours because of sunlight curving inside the atmosphere.)

If there isn't something like this in the official rules, does anyone have any particular input on the above table?

[Duke of Urrel]

I like the idea of dim-light concealment, and I also like the idea of dim-light Spot check penalties.

There were once rules for these things in Version 3.0, which I expanded for my own purposes. I have not abandoned them now that I use Version 3.5, but I have changed them a little.

On page 60 of my Dungeon Master's Guide (v.3.0), there are rules for Spot check penalties in dim light: –5 in moonlight, –10 in starlight. On page 133 of my Player's Handbook (v.3.0), the miss chance for "one-quarter" concealment (which I applied to moonlight) is set at 10%, the miss chance for "one-half" concealment is 20% (the equivalent of "normal" concealment in v.3.5), the miss chance for "three-quarters" concealment is 30%, the miss chance for "nine-tenths" concealment is 40%, and the miss chance for total concealment is 50% (as in v.3.5)

As I said, I have adopted some of these rules for v.3.5. I impose Spot check penalties of –4, –6, and –8 in areas of moonlight, moonshadow (the equivalent of shadowy illumination), and starlight, respectively. For creatures with Low-Light Vision, the corresponding penalties are zero, –4, and –6, respectively, and these creatures can see with a Spot check penalty of –8 in starshadow, which is near-total darkness. (Notice that the +8 racial bonus that owls add to their Spot checks in dim light neatly cancels out this penalty!) Concealment miss chances are 10% in moonlight, 20% in moonshadow or shadowy illumination, and 30% in starlight. For creatures with Low-Light Vision, the miss chances are zero, 10%, and 20%, respectively, and 30% in starshadow. I don't apply a 40% miss chance under any circumstances.

In the early morning and late evening hours, I impose a –5 "sun-in-the-eyes" penalty on the Spot checks of all creatures that are facing the sun. I don't impose any miss chance during daylight hours, unless there's thick fog or some kind of heavy precipitation. A 5% miss chance seems to me like too much trouble to bother with, but I think a –2 Spot check penalty for creatures with human vision would be appropriate for twilight, because that's half the penalty that I impose in moonlight. I'm ambivalent about using a 15% miss chance, because I don't know whether Low-Light Vision would reduce this miss chance to 5% or zero (and the difference is pretty slight).

This is all just for your consideration, Maginomicon. Thanks for drawing attention to this topic, which I think is well worth considering!

[Gerrtt]

May we ask why it is so important to keep track of what time it is in your game?

[Maginomicon]

May we ask why it is so important to keep track of what time it is in your game?You probably wouldn't like it.

Long story short (it would require a lot of pasting from my campaign house rules for me to fully explain it)... I run an intensely super-powered game full of a number of variants both in the SRD and of my own design. Most relevant to the discussion here, I use Reserve Points (http://www.d20srd.org/srd/variant/adventuring/reservePoints.htm) and Auto-regenerating Spell/Power/Infusion Points.

Reserve Points are spent 1 per minute (thus why it's important to keep track of the passing of minutes), and essentially prevent the need for the party to have an out-of-combat healing character (to a limit, as you eventually run out of reserve points).

"Auto-Regen" in entries in the table below means that the relevant points regenerate at a rate of 1 per level per hour distributed and back-loaded amongst 15min segments (i.e. A 6th-level Psion regenerates 1 power point after 15min, +2 after the 30min mark, +1 after the 45min mark, and +2 after the hour mark) with the clock starting when they first spend enough points such that they drop below their effective normal maximum (which for most characters is 2/3 their normal maximum).

{table=head]Type | After 1 hour regardless of rest | After 1 hour of rest | After 2 consecutive hours of rest
Wizard-type | 0 spell points regained | if currently lower, set at "1/3 maximum - spell point burn" | if currently lower, set at "2/3 maximum - spell point burn" |
Sorcerer-type | Auto-Regen, so "Caster Level"-worth of spell points regained, but only up to a limit of "2/3 maximum - spell point burn" | if currently lower, set at "1/3 maximum + amount recovered in an hour without rest - spell point burn", but only up to a limit of "2/3 maximum - spell point burn" | if currently lower, set at "2/3 maximum - spell point burn" |
Artificer-type | 0 infusion points regained | Auto-Regen, so "Caster/Manifester Level"-worth of infusion points regained, but only up to a limit of "2/3 maximum" | as an hour with rest, but once again |
Psion-type | Auto-Regen, so "Manifester Level"-worth of power points regained, but only up to a limit of "2/3 maximum" | N/A (rest is irrelevant) | N/A (rest is irrelevant)
[/table]

It works because among other difficulty factors in my game all encounters are rated at "APL+2" using the level-independent encounter generation method. Gods-help-them if they ever go into the Tomb of Horrors.