In the Lima mudlib, zero is dark, and anything positive is light.  Exactly
how bright anything is is completely ignored.  As long as there is a light
source in the room, you can see; if there isn't, you can't.

Much more complex systems are indeed possible.  In fact, it is not
particularly hard to do something more complex since almost all of the
code involved is in /std/object/light (most of the rest is in
/std/object/move and /std/container).

The rationale for *not* doing it is that it doing a *good* job of
implementing a complex multi-level light system isn't particularly
simple, and in our opinion adds little to the game.  For that reason,
we've gone with something simple, yet functional.

-Beek