Light Values for Rooms Using the Nightmare IV Mudlib
		     written by Descartes of Borg
			Last Modified: 940428

In all rooms or things in which players may enter, you need to specify a light
value for it using set_property("light", x); where x is an integer 
representing the light available to any player in the room, 
without adjustments for torches and such.  The following is a table of light 
values for different situations:

Outdoors:
   below -3: pitch black sky, usually indicating a magic darkness
   -3: a starless, moonless night sky
   -2: a starlit, moonless night
   -1: A night lit by a not-so bright moon
   0: Full moon night
   1: Night in a well lit town area, or late twilight
   2: Shadowy areas, early twilight, day with heavy cloud cover
   3: Average daylight
   4: Unusually bright daylight
   5: Blindingly bright daylight (too bright for most beings to see)

Indoors:
   -5: Magically darkned area.  No light exists.
   -4: Magically, darkened, but not as dark as a -5
   -3: Pitch black, no light sources
   -2: Very weak light sources
   -1: Weak sources of light, but still too dark for most humans to function
    0: Too dark for humans to see, but bright enough to allow them to function
    1: Dimly lit room
    2: A room of average lighting
    3: A brightly lit room
    4: A very bright room, usually because of a magic light source.
    5: Blindlingly, magically lit room

Keep in mind that any light value is acceptable.  If you want something so
magically darkened that no one may ever see in it, set_light(-1000);
But any values greater than 5 or less than -5 indicate magic at use.
Indeed, in some cases, numbers within that range indicate magic at work.