Request for Assistance with new rule concept.

[philreed]

I'm working on a new PDF detailing cyberassassins and special ops and have been beating my head against a new rule concept. My head hurts now so I thought I'd post what I have currently and ask for assistance. I'm open to all suggestions -- I really think that if this idea can be made to work it will be a great help in running stealth-based games.


New Rule: Shadowed Areas
Shadowed areas are those places that are darker due to the surrounding obstacles and terrain. These rules for shadowed areas are, in all honesty, a variant of the standard rules for cover and concealment and are an extreme simplification of how light and shadow work in the real world. This was done so that shadowed areas may be determined quickly when a new map is brought out for play. To determine the placement of shadowed areas on a map follow these steps.

Determine Stationary Light Source(s)
The GM indicates on the map – with either a marker or pen if using an eraseable map or with a counter or die on a normal map – any light sources. These can be hanging lights, the flickering of a fireplace, or the light of a distant streetlight. Stationary light sources may be positioned off of the map.

Determine Strength of Stationary Light(s)
Once the light source(s) are determined, the strength of each light must be set. The following table details possible types of light sources, the strength, and the shadow distance for each one.

Light Strength Shadow Distance
Candle 1 –
Torch 4 1
Naked Bulb 8 2
Flourecent Light 16 4
Searchlight 20 5
Partial Moon 24 6
Full Moon 40 10
Sun 60 15

Strength: The number of squares from the light source that are illuminated by the source. If no obstacle that could cast shadows is within that area the light source – while it does illuminate the affected spaces – does not create any shadowed areas.

Shadow Distance: This number is the base number of squares on the opposite side of the light source that are hidden in shadows by an obstacle.

Identify Obstacles
Now that you know where the light source is on your map, locate each obstacle on the map that is within range of the light source. Make a quick list of these obstacles and list their height in feet. Some common obstacles, and associated heights, may be found in the table below.
Obstacle Height
Table 3’

Mark Shadowed Areas
Now that you know the light sources and obstacles, it’s time to determine the shadowed areas on your map.

 

[philreed]

Some feedback I was already sent:

I like the concept it seems really appropriate for a d20 modern campaign/spycraft. (sort of a Metal Gear Solid feel) I saw nothing on this topic in the main book for spycraft (I would have thought it would). It seems simple enough of an idea, but it does create a number of issues though:

1) Different light sources will provide widely different shadow patterns.
For example:

a torch will flicker (alternating the strength and direction of the light) this will cause the shadows to move silently and provide inconsistent darkness.

a flourescent light is often diffuse leading to a large interference
pattern and often week shadows.

a direct source such as a flash like will provide a much sharper shadow than some others

2) Shadows darkness (penumbra vs. umbra) depends on how close the obstacle is to the light source and how much of its total light is blocked.

3) If you have two or more light sources in a given room it could
become very difficult to place shadowed areas. (even worse if different types, direct or diffuse, sources are combined)

4) Obstacle height will affect the shadows but so will the height of the
light source. (And likewise the angle between them) This will be clear
to most with the concept of sunlight and lengthening and shortening
shadows at different times of the day.

I think #1 and #3 will be apparent to the average gamer and the other
two complications only the diehard and those of us that have taught high
school science too long.

 

[Nellisir]

I'd look at the light sources as burst effects, like spells, and model the language that way. As it stands, it doesn't read at all like a "quick" way to model light and shadow.

I'm also not sure what advantage this variant is intended to offer over the standard rules, unless it's the addition of obstacles that create shadow. In that case, you might focus the rules on them, instead of the light sources.

Just some off-the-cuff thoughts,
Nell.

 

[jezter6]

I believe Mad Kaiser had some sort of 'light value' in Bare Knuckle Bar Fightin that you could look into for inspiration, and if it's open content you could probably just use bits of it without having the wrack your brain coming up with something new.

 

[HeapThaumaturgist]

Hrm, I think I'd like it even more simplified than that. As-is, even if I wanted to have some assassins in my game, there's a bit much work.

I'd go with standard rules, light sources like burst effects: Torch = 20' Light, 20' Shadow.

Bare light bulb, same thing. Shaded lamp, 15' and 15'. Desk lamp 5' and 5'.

Then divide a handful of objects into 5' sizes. For each 5' of height, it turns 5' of light behind it to shadow or 5' of shadow to darkness.

I'd say three ratings: Light, Shadow, Darkness

Use standard Object Sizes. Fine, Dimin. have no effect. Small only creates shadow/dark in its own square (if applicable), Medium 5', Large 10', etc etc.

Use D&D bursts with Light/Shadow in equal proportion in standard 5' sizes.

I think that would be very fast, very easy. Uses all standard terms and sizes that everybody is familiar with. A few simple rules like Obstructions stepping light down one level, you're good to go.

--fje

 

[Nellisir]

So, did you get anything figured out? Did we help at all?


Nell.

 

[Aaron2]

I'm working on a new PDF detailing cyberassassins and special ops and have been beating my head against a new rule concept. My head hurts now so I thought I'd post what I have currently and ask for assistance. I'm open to all suggestions -- I really think that if this idea can be made to work it will be a great help in running stealth-based games.

I've been thinking of similar rules for my WW2 game. Basically, rather than terrain providing just a set amount of concealment (for example, a bush provides one-quarter concealment), rather, the terrain would provides different values of concealment based on how many squares your are looking through (for example, a bush might provide one-quarter concealment for 5' thick, one-half concealment for 10' thick, three-quarters concealment for 15' thick, etc). It would be listed similar to how range increments work. That way even otherwise open terrain (like a field) would provide some concealment at a distance allowing careful characters to creep across otherwise open ground (thus avoiding the "casual observation" problem).

Using a scale for concealment where 1=one-quarter -> 5=total concealment you might get:

light foliage: 1 + 1 per 5 ft.
natural field: 0 + 1 per 30 ft.
football field (very short grass, perfectly flat): 0 + 1 per 100 ft.
dense foliage: 3 + 1 per 5 ft.
etc.

Poor lighting would then simply serve to reduce this range increment thus allowing the character to possibly get better concealment even when they would otherwise be within the range of the light. So while an area might be lit by moonlight, terrain would serve to provide better protection. Very poor lights (torches, flashlights, etc) wouldn't have much of an effect since the light would fade quickly before the terrain's concealment would come into effect.

I hope this made sense.


Aaron

 

[tjoneslo]

Phil, what you are descibing here is a process call ray tracing, used most frequently for generating photorealistic computer images. It's also used in most first person shooters to enable the computer to draw the scene (called ray casting here). I would use these terms to describe the effect you are looking, as anyone who is going to spend the time to calculate out this kind of effect will immediatly understand it.

My suggestion would be instead of trying to draw the lines on a map would be to build a set using minatures and real 3d walls (lego!) and use flashlights or lamps to provide the illumination. If the game is getting into the kind of detail where this map is a requirement, I'd prefer the real thing.