Illumination

Information
Illumination is a very minor change, it can be found at the very bottom left corner while looking in the Map interface. It is used to measure how bright or dark it is in places. When your next to a light source it can go from 10-15. When you enter a place that is unlit with no doors or windows, it can go all the way to 0. It is mostly important to know that monsters do spawn below 7.