Light problem in I7

How can you test to see if a specific room has light in it? I can’t seem to figure it out on my own.

That function is not directly available in I7. This should work (minimally tested):

To decide whether (R - room) offers light: (- OffersLight({R}) -).

This is a somewhat expensive test. It’s normally done just once per turn, in the player’s location (twice if the player moves). If you need to check this very frequently, or on lots of rooms per turn, you might need to code up a simplified test, based on what your game contains.

(For example, if your game has exactly one light source, you could just check “if R is the location of the lantern” and avoid a bunch of work.)

There’s also an example in the I7 manual that checks rooms for light by a rather roundabout route, but I’d guess this is even more expensive.