Creatures Caves

Drop Status-
Never: Objects are not allowed to be dropped by the hand in this room.
Above floor: Objects dropped by the hand will always teleport above floor-level if you try to drop them below it.
Always: Objects can be dropped on the floor, and under it. Items dropped under the floor will sit 'underground' (on the room's bottom boundary.)

Floor Value- How transparent the floor is. A value of 100 means Creatures can view the rooms below them, whereas a value of 0 means the floor is totally solid. I'm not sure what difference, if any, other values make.

In relation to Floor Value, when you edit two rooms' Linkage properties, the Openness value determines whether a room's boundaries between these two rooms are solid or passable. A value of 0 means solid wall that can't be seen through. 100 means they can see through it, but can't walk through it. 255 means it's totally open and passable. When you're looking at the coloured lines on the map, the colour (red, yellow, or green) represents these values in that order.

Additionally, Openness determines whether light, heat, and radiation can pass through the room. Along the top of the default C2 world, there's a thin row of sky rooms that act as light sources. This light penetrates into lower rooms, such as the rope bridge and desert, because all the rooms between the sky and the ground have an Openness of 255.

Heat from the Volcano source filters along the Ettin garden rooms and up into the volcano's mouth, with temperatures gradually dropping the further the rooms get from the source. (Edit: This doesn't seem to relate to Openness. Heat apparently passes between linked rooms based on distance and ignores Openness entirely.)